BILTEN PRIRODE PARK PARKA NATURE ......Bilten parka prirode Nature Park Bulletin Lonjsko polje Vol....

BILTEN PRIRODE PARKPARKA NATURE BULLETINBILTEN PRIRODE PARKPARKA NATURE BULLETIN

Go

din

a/V

ol.

6B

roj/N

o. 2

ISS

N:

1332

-068

8U

DK

:50

2.4

Go

din

a/V

ol.

6B

roj/N

o. 2

ISS

N:

1332

-068

8U

DK

:50

2.4

Bilten parka prirode

Nature Park BulletinLonjsko polje

Vol. 6/No. 2, 2004.

Ovaj projekt je izraðen uz pomoæ LIFE financijskog instrumenta Europske unije

This project has been carried out with the contribution of the LIFE financial instrument of the European Community

2 Bilten parka prirodeLonjsko polje

Nature Park BulletinVol. 6/No. 2, 2004

Nakladnik / Published by:

Glavni i odgovorni urednik / Editor in chief:

Uredništvo / Editorial board:

Tajnica uredništva / Administrative secretary:

Adresa uredništva / Adress of the Editorial Board:

Tel./faks:

E-mail:

Prijevod / Translation:

Lektor i korektor

Naklada:

Tisak

Javna ustanova "Park prirode Lonjsko polje"Lonjsko Polje Nature Park Public ServiceHR-44324 Jasenovac, Trg kralja Petra Svaèiæa bbHrvatska / Croatia

Goran Gugiæ

Darko Kovaèiæ, Radenko De�eliæ, Martin Schneider-Jacoby

Marija Kušina

Javna ustanova "Park prirode Lonjsko Polje"BiltenHR-44324 JasenovacTrg kralja Petra Svaèiæa bbHRVATSKA / CROATIA

++385 (0)44 672 080

[email protected]

Graham McMaster, Ivana Maguire

Ivan Jindra

Izlazi dva puta godišnje / The Bulletin appears twice yearly

500 primjeraka

Gratis tiskara - Kutina

IMPRESSUM

SADR�AJ / CONTENTS

Bilten parka prirodeLonjsko poljeNature Park BulletinVol. 6/No. 2, 2004

3

Uvod ........................................................................................................................................................ 4.................................................................................................................................................... 4

Mr.sc. Ivica Milkoviæ:Stanje šuma srednje Posavine ............................................................................................................... 6

.................................................................................... 6

Ivan Štanfar, dipl.ing.:Iskaz površina i stanje šuma na podruèju parka prirode Lonjsko poljekojim gospodari Uprava šuma, podru�nica Nova Gradiška ................................................................... 12

.................................................................... 12

Dubravko Janeš, dipl. ing. šum.:Stanje i problematika šuma na podruèju parka prirode Lonjsko polje ................................................... 20

................................................................................................................... 20

Tihomir Pejnoviæ, dipl.ing.:Nizinske šume ........................................................................................................................................ 23

...................................................................................................................................... 24

Doc. dr. sc. Igor Aniæ:Zagrebaèka škola uzgajanja šuma i gospodarenje nizinskim šumama .................................................. 25

............................................ 25

Dr.sc. Juro Èavloviæ:Stanje i projekcije buduæega gospodarenja i razvoja dobne strukture u šumamahrasta lu�njaka i poljskog jasena na podruèju parka prirode Lonjsko polje ............................................. 38

........ 38

Dra�en Ivaštinoviæ, dipl.ing.:Prikaz stanja dobnih razreda na podruèju parka prirode Lonjsko polje ................................................... 50

................................. 50

doc. dr. sc. Ivica Tikviæ, prof. dr. sc. Zvonko Seletkoviæ:Propadanje stabala i poremetnja stabilnosti nizinskih šumskih ekosustava .......................................... 58

............................................ 58

Nova Gradiška, 18. o�ujka 2004:Zakljuèci sa struènog skupa - Stanje šuma u parku prirode Lonjsko polje,gospodarenje i oèuvanje krajobrazne i biološke raznolikosti ................................................................. 68

................................. 68

Preface

The condition of the forests of central posavina

Schedule of area and condition of forests in the area of the Lonjsko poljenature park managed by the Nova Gradiška forest district

The current state of and problems connected with the forests in the areaof Lonjsko polje nature park

Lowland forests

The Zagreb school of silviculture and the management of lowland forests

The present condition and a projection of the future management and development/agestructure in common oak and narrow-leaved ash forests in the area of Lonjsko polje nature park

A review of the condition of age classes in the area of Lonjsko polje nature park

Dieback and disturbance of the stability of the lowland forest ecosystems

Conclusions of the conference - the condition of the forests in the Lonjsko poljenature park management and preservation of landscape and biological diversity

PREFACE

On behalf of Lonjsko Polje Nature Park PublicInstitute I bid you welcome, distinguished fellowforesters, scientists, ecologists, ecologists,journalists and representatives of local governmentand the competent central government bodies andrepresentatives of the conservation areas, here, inNova Gradiška, at this conference concerning theCondition of the Forests in Lonjsko Polje Nature Parkthe Management and Preservation of Landscapeand Biological Diversity.

I think that Nova Gradiška is a location very wellselected for the holding of such a conference. And Ican tell you why: it is now several years, and I recallthat I had not at that time begun to complain aboutthe appearance of the first grey hairs brought on bydirectorial cares when in search of data about thearea of today's nature park I went over the militaryarchives in Vienna. In a pile of books that I washanded by the archivist there was one the title ofwhich was: Forsteinrichtungswerk für das Neu-Gradischkaner Regiment or the Forest ManagementPlan of the Nova Gradiška Regiment, dated 1882.Anyone who can read this Plan can get a fascinatinginsight into the state, structure and history of thelowland riparian forests in the lower part of today'snature park.

Lowland riparian forests not only inherentlyconstitute an invaluable biological and landscapevalue, not only constitute something that makesCroatia recognisable at the international level, but inthe lowland riparian forests a great deal of the historyof the profession of forester in Croatia is reflected.By this I mean that the foresters have taken an activepart in the creation of the unique cultural landscapeof Lonjsko Polje Nature Park. And today too theyhave to be an integral part of it.

From this derives the great responsibility that we allshare. It requires the maximum seriousness andprofessionalism in our approach, it requires, andallow me to use this kind of expression, thesilviculture skills of each forester who manages thelowland riparian forests, and it seeks and forgive thisexpression again the management skills of thosewho are the stewards of the protected areas in orderfor us to be able to preserve the lovely, ancientpicture that in 1888, Josip Kozarac, precisely here, intoday's Lonjsko Polje Nature Park described in hissketch Slavonian Woods.

It is from this point of view that we would like to worktoday at this conference.

UVOD

U ime Javne ustanove Park prirode Lonjsko poljepozdravljam sve vas, poštovani kolege šumari,znanstvenici, ekolozi, novinari i predstavnici lokalneuprave, mjerodavnih dr�avnih tijela i zaštiæenihpodruèja, ovdje u Novoj Gradiški, na struènom skupuStanje šuma u Parku prirode Lonjsko polje,gospodarenje i oèuvanje krajobrazne i biološkeraznolikosti.

Mislim da je Nova Gradiška dobro izabrana zaodr�avanje takvog skupa. Reæi æu vam i zašto. Imatome veæ nekoliko godina - sjeæam se da se tada jošnisam mogao po�aliti na pojavu prvih sijedih vlasizbog ravnateljskih briga - otkako sam, u potrazi zapodacima o podruèju današnjega Parka prirode,pronašao ratni arhiv u Beèu. U hrpi knjiga, koje mi jeuruèio arhivar, bila je i jedna naslovljena"Forsteinrichtungswerk für das Neu-GradischkanerRegiment", u prijevodu "Šumskogospodarskaosnova za novogradišæansku pukovniju", izdanagodine 1882. Onome tko tu osnovu zna èitati, otvarase fascinantan uvid u stanje, strukturu i povijestnizinskih poplavnih šuma u donjem dijeludanašnjega Parka prirode.

Nizinske poplavne šume, ne samo što su same posebi neprocjenjiva biološka i krajobrazna vrijednost,ne samo što znaèe nešto po èemu je Hrvatskaprepoznatljiva na meðunarodnoj razini nego se unizinskim poplavnim šumama ogleda velikim dijelomi povijest šumarske struke u Hrvatskoj. �elim reæi:šumari su aktivno sudjelovali u stvaranjujedinstvenoga kulturnog krajobraza parka prirodeLonjsko polje. Oni i danas moraju biti njegov sastavnidio.

Iz toga proizlazi velika odgovornost sviju nas;najveæa ozbiljnost i profesionalnost u našem pristupudopustite mi takav izraz - uzgajivaèko umijeæesvakoga šumara koji gospodari nizinskim poplavnimšumama i - dopustite mi ponovno takav izraz -upravljaèko umijeæe onih koji zaštiæenim podruèjemupravljaju kako bi se oèuvala ta prekrasna drevnaslika koju je Josip Kozarac godine 1888. upravoovdje, na mjestu današnjega Parka prirode Lonjskopolje, opisao u svojoj crtici "Slavonska šuma".

S takvom svrhom �elimo danas raditi na ovomstruènom skupu. Za�ivjela je naša suradnja i naterenu. Ona je veæ dosegnula takve razmjere da sadaveæ moramo tra�iti konkretna rješenja za nekeprobleme, iz èega bi, po mojemu mišljenju, trebaleproizaæi konkretne upute našim operativcima kako binaša suradnja bila što djelotvornija, racionalnija i štomanje optereæena administrativnim postupcima.

Struèni skup - Stanje šuma u parku prirode Lonjsko polje - gospodarenje i oèuvanje krajobraznei biološke raznolikosti; Nova Gradiška, 18.III.2004.

The condition of the forests in the Lonjsko polje nature park management and preservationof landscape and biological diversity - Nova Gradiška 18.03.2004.




5

Zato molim predavaèe da se strogo dr�e ogranièenjapredviðenih programom kako bismo osigurali vrijemeza bezuvjetno potrebnu raspravu, a sudionike da se uraspravi usredotoèe na konkretne i operativneprijedloge koji se odnose na podruèje parka prirodeLonjsko polje.

Veseli me što se Šumarski fakultet ukljuèio kaosuorganizator ovoga struènog skupa, pa æu iskoristitipriliku da za to zahvalim predstavniku Fakulteta,dekanu prof. Zvonku Seletkoviæu.

Veseli me što meðu nazoènima mogu pozdraviti isvoga prethodnika, šumara, gospodina StjepanaCrnka.

Napokon, svima nama �elim uspjeh ovoga struènogskupa.

Ravnatelj:

Goran Gugiæ

Collaboration between us in the field has come to life,too. It has assumed such dimensions already thatnow we have to accept the search for concretesolutions of certain problems that in my opinionshould result in the finding of concrete instructions tooperational staff so that our collaboration should bestill more efficient, rational and to the least extentpossible burdened with administrative andmanagement procedures. For this reason I wouldlike to ask lecturers to keep strictly to the timetableforeseen in the programme so that we should be ableto provide the time for the absolutely essentialdiscussion, and so that participants in the discussionshould be able to concentrate on the concrete andoperational proposals that relate to the area ofLonjsko Polje Nature Park. I am very happy that theFaculty of Forestry has joined in as co-organiser ofthe conference, and I would like to give specialthanks to the representative of the faculty, DeanProfessor Zvonko Seletkoviæ.

I am also happy to be able to see among thosepresent my predecessor, Mr Stjepan Crnko theforester.

And now I would like to wish us all a very successfullyproduced conference.

Managing director

Goran Gugiæ





STANJE ŠUMA SREDNJEPOSAVINE

Uvod

1. Šumski ekosustavi na mikrouzvisinama(grede)

2. Šumski ekosustavi u mikroudubinama (nize)

3. Šumski ekosustavi u mokrimmikroudubinama (bare)

Površina šuma i šumskih zemljišta

U radu je prikazano stanje šuma na podruèju izmeðu�eljeznièke pruge Zagreb - Slavonski Brod, nasjeveru, i rijeke Save, na jugu, od Dubrovèaka i IvaniæGrada, na zapadu, do rijeke Orljave, na istoku.Rijeè je o nizinskom podruèju, veæim dijelom upoplavnom pojasu rijeke Save. Uz Savu, bitan utjecajna hidrološke prilike ovoga podruèja imaju i njezinepritoke (Orljava, Šumetlica, Sloboština, Ilova,Èesma, Lonja, Pakra, Trebe�). Voda kao ekološkièimbenik (oborinska, poplavna ili podzemna)presudno utjeèe na stanje i sastav nizinskih šumaPosavine.Hidrotehnièki i infrastrukturni zahvati promijenili suvodni re�im, što znatno pridonosi nestabilnosti ipropadanju šumskih ekosustava na promatranompodruèju.Glavnina tih šuma tvori retenciju za regulaciju visokihvoda rijeke Save.U nizinskim šumama Posavine razlikuju se tri skupineekosustva koji se pojavljuju u razlièitim oblicimadolinskog mikroreljefa:

Predstavnik ove skupine ekosustva je šuma hrastalu�njaka i obiènoga graba

Predstavnik ove skupine ekosustava je šumahrasta lu�njaka i velike �utilovke s rastavljenimšašem

Predstavnik ove skupine ekosustava je šumapoljskog jasena s kasnim drijemovcem

Prikaz stanja šuma ovdje se temelj i našumskogospodarskim osnovama podruèja, stanje1996. godine.

Dr�avne šume i šumska zemljišta na promatranompodruèju pokrivaju 51 697 ha, a glavninom gospodari

(Carpino betuli-Quercetum roboris typicum Rauš 71)

(Genisto elatae-Quercetum roboriscaricetosum remotae Ht. 38)

(Leucoio-Fraxinetum agnustifoliae Glav. 59)

THE CONDITION OF THE FORESTSOF CENTRAL POSAVINA

Introduction

1. Forest ecosystems on micro-elevations

2. Forest ecosystems in mirco-depressions.

3. Forest ecosystem in wet micro-depressions(pools)

Area of forests and forest lands.

This paper considers the state of affairs in the forestsin the area between the Zagreb-Slavonski Brodrailway line to the north and the Sava River to thesouth, from Dubrovèak and Ivaniæ Grad to the west,and the Orljave River to the east.This is a lowland area, most of it in the floodplain ofthe Sava River. As well as the Sava, the hydrologicalcircumstances in the area are crucially influenced byits tributaries (the Orljava, Sumetlica, Slobostina,Ilova, Èesma, Lonja, Pakra and Trebe�). Water isthe ecological fact as precipitation, as flooding orunderground water that has a crucial effect on thecondition and composition of the lowland forests ofPosavina.Hydro-engineering and infrastructure operationshave changed the water regime, which mainly hasled in turn to instability in and dieback of forestecosystems in the region under observation. Themajor part of the forest area constitutes a floodwaterretention area for the regulation of high water in theSava River.In the lowland forests of Posavina, we candistinguish three groups of ecosystems that areinundated with various forms of valley micro-relief.

Arepresentative of this group of ecosystems is thecommon oak and hornbeam forest (Carpinobetuli-Quercetum roboris typicum Raus 71)

Arepresentative of this group of ecosystems is theforest of common oak and broom with scatteredreeds. Genisto elatae-Quercetum roboriscaricetosum remotae Ht.38)

Arepresentative of this group of ecosystems is theforest of narrow-leaved ash with snowflake(Leucoio-Fraxinetum agnustifoliae Glav.59).

An account of the condition of the forests is given,according to the forest management plan of the area,as of 1996.

The total area of state-owned forests and forestlands in the area under observation comes to 51,697




7

Tablica 1.

poduzeæe “Hrvatske šume” d.o.o. (49 941 ha),manjom površinom dr�avnih šuma gospodareŠumarski fakultet (513 ha) i Hrvatske vode (1243 ha).Privatne šume u tom podruèju zauzimaju izmeðu 10 i20% površina dr�avnih šuma. Dakle, dok su sadašume srednje Posavine prete�no u dr�avnomvlasništvu, prije Drugoga svjetskog rata u dr�avnomvlasništvu bilo je oko 42% šuma, imovne opæine sugospodarile sa 34% ukupnih površina, zemljišnezajednice sa 16%, a ostatak su bili razlièiti obliciprivatnoga vlasništva.Otvorenost šuma prometnicama iznosila je 1996.godine 8,9 km/000 ha.

Struktura površina šuma i šumskih zemljišta zapovršine kojima gospodare Hrvatske šume d.o.o.prikazana je u sljedeæoj tablici:

ha, most of it being managed by the firm CroatianForests d.o.o. (49,941 ha). A small area of the state-owned forests is managed by the Forestry Faculty(513 ha) and Croatian Water (1,243 ha). The area ofprivate forests inside this area comes to between 10and 20% of the area of the state-owned forests.Thus, at the moment the forests of central Posavinaare mostly state-owned, while before World War IIabout 42% of the forests were state-owned;corporations managed about 34% of the total area,land communities about 16%, with the rest being invarious forms of private ownership.The forests were accessible by road in 1996 in theratio of 8.9 km/000 ha.

The structure of the areas of forests and forest landswith respect to the areas managed by CroatianForests d.o.o. is shown in the following table:

Table 1.





U parku prirode Lonjsko polje nalazi se oko 29 000 hadr�avnih šuma ili 58% nizinskih šuma na podruèjusrednje Posavine.

Drvna zaliha iskazana je na površini od 34 418 hasastojina starijih od prvog dobnog razreda; hrastlu�njak i jasen tvore 88% drvne zalihe.

Drvna zaliha i prirast

Within Lonjsko Polje Nature Park there are about29,000 ha of state-owned forests, or about 58% ofthe lowland forests in the area of Central Posavina.

Timber reserves are expressed on the area of34,418 of stands older than the first cohort, commonoak and narrow-leaved ash making up 88% of thetimber reserves.

Timber reserves and increment

Tablica 2.

Table 2.




9

Namjena šuma i ureðajni razredi Purpose of Forests and Management Classes

Tablica 3.

Table 3.





Dobna struktura i normalitet

Zdravstveno stanje šuma

Ocjena stanja i prijedlozi za poboljšanje

S obzirom na to da ureðajni razredi sjemenjaèahrasta lu�njaka i sjemenjaèa poljskog jasena èineviše od 93% ukupnih obraslih površina, pokazatæemo njihove dobne strukture i normalitet sastojina.Šumskogospodarskom osnovom podruèja propisanietat glavnog prihoda za I/1 gospodarskopolurazdoblje na površini od 1901 ha za ureðajnirazred hrasta lu�njaka (N=3605 ha) i 2619 ha zaureðajni razred poljskog jasena (N=3313 ha)usmjeren je na postizanje normalne dobne strukturesastojina, što je, naravno, dugoroèna zadaæa.

Zdravstveno stanje šuma na promatranom podruèjunajbolje oslikava podatak o udjelu suhih i ošteæenihstabala hrasta lu�njaka u ukupnom etatu za razdoblje1996. - 2002. koji iznosi 35%.

Stanje šumskih ekosustava na promatranompodruèju u pogledu proizvodnosti, ekološkestabilnosti i biološke raznolikosti nije najbolje.

Uzroke takvom stanju vidimo u sljedeæimèimbenicima:

1. Infrastrukturnim i hidrotehnièkim zahvatimapromijenjen je vodni re�im, podruèje je pretvoreno uperiodièku retenciju, što se višestruko nepovoljnoodra�ava na stabilnost ekosustava:· površine u retenciji postaju vla�nije, na površinama

uz duboke kanale snizuje se razina podzemnevode

· slijeganje leda nakon povlaèenja zimskih poplavasavija i lomi mlada stabalca

· s obzirom na to da je prosjeèno godišnje trajanjepoplave u retenciji tijekom vegetacijskogarazdoblja oko 23 dana, dolazi do propadanja ponikai pomladka šumskih vrsta drveæa i grmlja

· za vrijeme poplave, stoka, koja bez nadzora boraviu šumi, divljaè i glodavci migriraju na preostalenepoplavljene površine, kojih bude oko 10%, gdjepoèine znatne gospodarske i ekološke štete

· zbog dugotrajnih poplava vrlo su ogranièenemoguænosti izvoðenja sjeèe glavnoga prihoda upropisanim vremenskim razmacima, a zbograskvašenoga tla nastaju znatne štete na tluprilikom privlaèenja drvnih sortimenata.

2. Poèetkom prošloga stoljeæa šumama na ovom

Age Structure and Even-Age Distribution

The health of the forests

An evaluation of the state of affairs andproposals for improvements

Since the management classes of common oak seedtrees and narrow-leaved ash seed trees constituteover 93% of the total of covered areas for thosemanagement classes, we give a review of the agestructure and the even-age distribution of the stands.In the forest management plan of the area theprescribed felling cut for the I/1 management half-period on an area of 1901 for the management classof common oak (N=3605 ha) and 2619 ha for themanagement class of narrow-leaved ash (N=3313ha) is aimed at the achievement of an even-agedstructure of the stands, which is, of course, a long-term assignment.

The health of the forests in the area underconsideration is best imaged by the figuresconcerning the proportion of dead and damagedcommon oak trees in the total permissible cut for theperiod of 1996-2002, which comes to 35%.

The situation of the forest ecosystems in the areaobserved with respect to productivity, ecologicalstability and biological diversity is not optimal.

The causes of this state of affairs can be ascribed tothe following factors:1. Infrastructure operations and hydro-engineeringhave changed the water regime; the area has beenturned into an occasional floodwater retention area,which reflects unfavourably upon the stability of theecosystem in several ways:· the areas in the retention area become more

humid, in the areas along the deep channels thelevel of underground water drops;

· the settling of ice after the withdrawal of the winterfloods breaks and bends the young trees;

· since the average annual duration of the flooding inthe retention area during the vegetation area isabout 23 days, the shoots and young trees of foresttrees and shrubs decay;

· during the time of the floods, the livestock roamswithout control in the forest, the game and rodentsmigrate to the non-inundated areas, about 10%,doing considerable economic and ecologicaldamage;

· because of the long-term floods, there are verylimited opportunities for carrying out the loggingoperations for the main cut in the prescribed intervalsof time, and because of the waterlogged ground,damage necessarily is incurred by the ground whilethe wooden assortments are being hauled.




11

podruèju poèela se širiti biljka(divlji bagrem ili èivitnjaèa) koja od prirode dolazi napodruèju Floride. Ta biljka, èije se sjeme uglavnom širivodom za vrijeme poplava, vrlo agresivno zauzimasloj grmlja u nizinskim šumama i onemoguæujeprirodnu obnovu sastojina te, potiskujuæi biljke kojetvore sloj grmlja i prizemnog bilja u ovim šumama,znatno su�ava biološku raznolikost;

3. Polovicom prošloga stoljeæa holandska bolestbrijesta, èiji je uzroènik gljiva ( ),uzrokovala je intenzivno sušenje i nestajanjenizinskog ili poljskog brijesta ( ) iznizinskih šuma. Udio nizinskog brijesta, koji je dotada èinio i do 30% drvne zalihe nizinskih šuma,smanjen je ispod 1%, što takoðer loše utjeèe naekološku stabilnost i biološku raznolikost šumaovoga podruèja.

Predla�emo zajednièko sudjelovanje šumarskestruke i zaštite prirode na popravljanju utvrðenogastanja, i to sljedeæim aktivnostima:

i s t ra� i van jem i p red lagan jem mode lanajpovoljnijega vodnog re�ima srednje Posavinerazradom standarda i pravila za ispašu stoke našumskim površinama (broj grla po jedinici površine,obveze vlasnika, površine na kojima nijedopuštena ispaša i sl.)izradom standarda o ekološki prihvatljivom brojudivljaèi u šumskim ekosustavima i obvezomlovozakupnika u pogledu naknade štete kojudivljaè uzrokujesuradnjom na izradi projekata ekološki prihvatljivogotvaranja šuma šumskim prometnicama, èime bise smanjile štete koje nastaju privlaèenjem drvnihsortimenataistra�ivanjem ekološki prihvatljivih metoda zaiskorjenjivanje èivitnjaèe iz nizinskih šumskihekosustava i participiranje u troškovimaizradom i zajednièkim provoðenjem projektarevitalizacije nizinskog brijesta.

Amorpha fruticosa L.

Ophiostoma ulmi

Ulmus carpinifolia

�

�

�

�

�

�

2. At the beginning of the last century, the plant(bastard indigo occurring

naturally in Florida) began to spread in the area.This plant, the seeds of which are mainlydisseminated by water during the time of flooding,very aggressively occupies the shrub layer in thelowland forests and precludes the naturalregeneration of stands and suppresses plants thatmake up the epigeal growth and shrug layer, thusconsiderable reducing biological diversity in theseforests.

3. In the middle of the 20th century, the Dutch elmdisease, the etiologic agent of which is the fungus

, caused the intensive witheringand disappearance of the smooth leaf elm,

, from the lowland forests. The proportionof lowland elm up to that time had constituted up to30% of the timber reserves of the lowland forests,but was reduced to less than 1%, which has leftfurther negative consequences on the ecologicalstability and biological diversity of the forests of thisregion.

We propose a joint approach between the forestryprofession and nature conservation to remedy thesituation as established, through the followingactivities:

research and proposal for a model for theoptimisation of the water regime of CentralPosavinaelaboration of standards and rules for the grazingof livestock in the forest areas (number of head perunit of area, obligations of owners, areas in whichgrazing is not allowed, and so on);drawing up a standard for the ecologicallyacceptable numbers of game in the forestecosystems and the obligations of game leaseswith respect to the damage caused by game;collaboration on the elaboration of projects ofecologically acceptable opening up of the forestswith forest roads, thus reducing the damageresulting while hauling timber;research into ecologically acceptable methods forthe eradication of bastard indigo from the lowlandforest ecosystems and participation in the costs;elaboration and joint implementation of a projectfor the revitalisation of the lowland elm.

Amorpha fruticosa L

Ophiostoma ulmiUlmus

carpinifolia

�

�

�

�

�

�

Mr.sc. Ivica MilkoviæHrvatske šume d.o.o.

Slu�ba za Ureðivanje šumaLj. Farkaša Vukotinoviæa 2, 10000 Zagreb





ISKAZ POVRŠINA I STANJE ŠUMANA PODRUÈJU PARKA PRIRODELONJSKO POLJE KOJIMGOSPODARI UPRAVA ŠUMA,PODRU�NICA NOVA GRADIŠKA

1. Stanje površina šuma i šumskog zemljišta

SCHEDULE OF AREA ANDCONDITION OF FORESTS IN THEAREA OF THE LONJSKO POLJENATURE PARK MANAGED BYTHE NOVA GRADIŠKA FORESTDISTRICT

1. Condition of area of forests and forest land

1.a. Minirane površine šuma i šumskog zemljišta 1.a. Mined areas of forest and forest land




13





2. Površina ureðajnih razreda 2. Areas of management classes




15

3. Drvna zaliha po vrstama drveæa 3. Timber reserves per species of tree





4. Tablica dobnih razreda 4. Table of age classes




17

5. Ukupno propisani etat 5. Total permissible cut

6. Ukupno propisani uzgojni radovi 6. Total prescribed silviculture works

Uzgojni radovi JBR

Silviculture works





Radovi PBR

Works of PBR

IZVRŠENI ETAT U PROŠLIH 10 GODINA PERMISSIBLE CUT EXECUTED IN THE LASTTEN YEARS

GLAVNI PRIHOD

Redoviti 453 230Sluèajni 14 164Izvanredni 2 174

MAIN CUT

Regular 453 230Accidental 14 164Special 2 174




19

PRETHODNI PRIHOD

Redoviti 163 193Sluèajni 167 496

PRELIMINARY CUT

Regular 163 193Accidental 167 496

Ivan Štanfar, dipl. ing. šum.Hrvatske šume d.o.o.

Podru�nica Nova GradiškaSlu�ba za Ureðivanje šuma

Strossmazerova 11, 35400 Nova Gradiška





STANJE I PROBLEMATIKA ŠUMANA PODRUÈJU PARKA PRIRODELONJSKO POLJE

Uprava šuma, Podru�nica Zagreb gospodari sa 79630 ha dr�avnih i 75 800 ha privatnih šuma.Posebnost Podru�nice je u tomu da gotovo 30%površine dr�avnih šuma kojima gospodari zauzimajutri parka prirode: Medvednica - 8200 ha, �umberak-Samoborsko gorje - 5100 ha i, najviše, Lonjsko polje -9700 ha. Osim više manjih površina šuma posebnenamjene, rasporeðenih na cijelom podruèju, �elimistaknuti i dvije gospodarske jedinice: park-šuma, i tona podruèju Grada Samobora, G. J. "Tepec-Palaènik-Stra�nik" od 345 ha, i park-šume Grada Zagreba,površine 360 ha.Uprava šuma Podru�nica Zagreb meðu prvima je -što je dokaz dosadašnjega kvalitetnog i pravilnoggospodarenja - dobila FSC-certifikat, i to za podruèjeŠumarije Krapina 17. 12. 2000., a za podruèje cijelePodru�nice 21. 6. 2001.Uprava šuma Podru�nica Zagreb na podruèju parkaprirode Lonjsko polje gospodari sa 9700 ha šuma išumskog zemljišta, što je rasporeðeno na trišumarije: Popovaèa, Kutina i Lipovljani, a kojeobuhvaæaju tri gospodarske jedinice "Popovaèkenizinske šume", "Kutinske nizinske šume" i "JosipKozarac". Unatoè tomu što se nalaze u podruèjuparka prirode, sadašnji zakonski i podzakonskipropisi tretiraju ih kao normalne gospodarske šume.No tu tvrdnju pobijaju ogranièenja u uvjetima zaštiteprirode, dobivena od Ministarstva kulture, primjerice,da oplodnu sjeèu treba provoditi u što duljemvremenskom razdoblju, zatim zabranu uporabekemijskih sredstava, osim uz posebnu dozvoluMinistarstva, uputu da treba ostavljati zaštitne zoneoko gnijezda ptica te pojedinaènih stabala nasjeèinama. Uz ova i ostala ogranièenja, premaZakonu o zaštiti prirode, proizlazi da to nisu normalnegospodarske šume.Prema podacima iz "Osnova gospodarenja" na ovompodruèju najzastupljenije su sastojine ureðajnograzreda hrasta lu�njaka - ophodnje 140 godina - 64%,te poljskog jasena - ophodnje 80 godina - 23%. Odostalih ureðajnih razreda, koji ukupno zauzimaju13%, a zastupljeni su u malom postotku, navodimureðajne razrede graba, crne johe, bijele vrbe i topola(domaæe i euroamerièke).Stanje zastupljenosti po vrstama drveæa je sljedeæe:hrast lu�njak je zastupljen sa 55%, poljski jasen 33%,a slijedi grab 5%, joha 3%, dok su sve ostale vrstedrveæa zastupljene s preostalih 4%.Stanje sastojina na ovom podruèju prema dobnimrazredima je sljedeæe: najzastupljeniji je I. dobnirazred - 25%, zatim V. - 19%, VI. - 15%, VII. - 13%,

THE CURRENT STATE OF ANDPROBLEMS CONNECTED WITHTHE FORESTS IN THE AREA OFLONJSKO POLJE NATURE PARK

The Forest Administration Zagreb Branch manages79,630 ha of state-owned and 75,800 ha of privately-owned forests. The particularity of this branch is thatalmost 30% of the area of the state-owned foreststhat it manages is occupied by three nature parks:Medvednica, 8200 ha; �umberak-Samobor Hills,5,100 ha; and the largest, Lonjsko Polje, 9,700 ha.Apart from several smallish areas of special purposeforests distributed over the whole area, I would like tomake particular reference to two economic units offorest park, the 345 ha Tepec-Palaènik-Stra�nik parkin the area of the city of Samobor; and the ForestPark of the city of Zagreb, on an area of 360 ha.The Forest Administration Zagreb Branch wasamong the first to obtain an FSC certificate asevidence of the high quality and proper managementto date, for the area of the Krapina Forest Unit, inDecember 2000, and for the area of the branch as awhole in June 2001.The Forest Administration Zagreb Branch manages9,700 ha of forest and forest land in the area ofLonjsko Polje Nature Park, distributed over threeforest units: Popovaèa, Kutina and Lipovljani,covering three economic units: Popovaèa lowlandForests, Kutina lowland forests, and Josip Kozarac.In spite of the fact that they are in the nature park, thecurrent statutory and byelaw regulations affect totreat them as normal industrial forests. This howeveris contradicted by the constraints in the conditions ofnature protection sent down by the Ministry ofCulture, of which I would like to highlight the seedingcut having to be carried out in as long a period aspossible, the ban on the use of chemical preparationsexcept with the special permission of this ministry,leaving a buffer zone around the nests of birds andgiven trees in the felling areas. From these and otherconstraints according to the Nature Protection Law, itcan be seen that these are not actually normalindustrial or commercial forests.According to data from the General ManagementPlan, in this area the most highly represented arestands of the management class of common oak,140 year rotation, 64%; and of narrow-leaved ash,rotation 80 years, 23%. Of the other managementclasses, which occupy all told 13%, and arerepresented in small percentages, I would refer to themanagement classes of hornbeam, black alder,white willows, and poplars (domestic and EuropeanandAmerican).The composition of the forests according to treespecies is as follows. Common oak accounts for55%, narrow-leaved ash for 33%, and then comeshornbeam, with 5%, alder with 3%, and all the other




21

zatim slijede sastojine III. i IV. dobnog razreda - 9%, teII. sa 8% i VIII. sa 2%. Od ukupne drvne zalihe kojaiznosi 2 500 000 m sijeèe se prosjeèno godišnje2,2% ili 81% od prirasta. Od ukupno sjeèomrealizirane drvne zalihe preko 23% drvne zaliherealizirano je u sušcima, što znatno utjeèe nanormalno gospodarenje ovim sastojinama i znatnosmanjuje prihod iz ovih šuma.Dosadašnjim istra�ivanjima ekosustava poplavnihpodruèja, a u svezi s pojavom sušenja domaæih vrstadrveæa (lu�njak, jasen, brijest), utvrðena jemeðusobna ovisnost razvoja biljnih zajednica, tla ivoda. Program rješavanja vodnog re�ima ovogpodruèja zapoèinje 1963., nakon poplave u graduZagrebu, kada zapoèinje regulacija toka rijeke Save injezinih pritoka na podruèju srednje Posavine,izgradnja odteretnih kanala (Lonja - Strug, Sava -Odra, Zelina - Èesma). Uz veæe, izgraðen je i cijeli nizmanjih kanala i jaraka, koji takoðer imaju veliki utjecajna vodni re�im. Osim kanala na vodni re�im, velikiutjecaj ima i mnogo javnih i šumskih prometnicaizgraðenih u tom razdoblju.Svi spomenuti radovi narušili su dotadašnji prirodnire�im poplava ovog podruèja, a podruèje slu�i kaoretencioni prostor, odnosno podruèje na koje sekontrolirano izlijeva voda radi sprjeèavanja poplavena podruèju koje se �eli zaštititi.Stvaranjem retencije znatno je poremeæenadotadašnja dinamika dotoka, zadr�avanja i otjecanjapoplavnih voda, a tijekom godine mijenja se istruktura tla, uz sve veæu akumulaciju štetnih tvari.Posljedica dugog zadr�avanja vode u retencionompolju je zagrijavanje vode i gubitak kisika u vodi i tlu,što, uz veæ spomenutu poveæanu koncentracijuštetnih tvari u tlu, uzrokuje propadanje i odumiranjekorijena.Dalje, treba reæi da je tim radovima na regulacijivodotoka narušen vodni re�im i u ostalom dijelugodine, i to u onom najva�nijem segmentu, a to jerazina podzemnih voda, koje su najva�nije zaopstanak sastojina. Spuštanje razine podzemnihvoda glavni je razlog sušenja sastojina na ovompodruèju, a procijenjeno je da je od 1963. do danassušenjem ošteæeno oko 500 000 m drvne zalihe.Osim lošeg utjecaja na razvoj i opstanak starihsastojina, na ovom podruèju pojavljuju se velikiproblemi obnove sastojina. Dalje zadr�avanje vode uretencionom polju tijekom proljeæa i u ljetnomrazdoblju utjeèe na propadanje sjemena i, osobito,ponika i pomlatka u sastojinama koje su u procesuobnove, pa èak i u onima kojima je poèetna fazaobnove završena, izvršen dovršni sjek. Zimi,zaleðivanjem tih površina, nastaju novi problemi: ledobuhvati mlade biljke i ako poraste razina vode,išèupa ih iz zemlje, odnosno ako razina vode opadne,pritiskom nastaju prelomi i ošteæivanja mladih biljaka.Osim spomenutih šteta, led ošteæuje i ograde

3

3

kinds of tree account for the remaining 4%.The situation of the stands in this area, according tocohort, is as follows: the most highly represented isthe 1st age class, 25%; then the 5th, 19%; the 6th,15%; the 7th, 13%; then come stands of the 3rd and4th cohort, 9%; the 2nd, with 8%, and the 8th, 2%. Ofthe total timber stocks that come to 2,500,000 cubicmetres, the average annual cut is 2.2% or 81% of theincrement. Of all the timber stocks realised throughfelling, over 23% is realised in dead trees, whichconsiderably affects normal management of thesestands and considerably reduces the earnings fromthese forests.Investigation to date into the ecosystems of theriparian area, in connection with the phenomenon ofthe dying of the domestic species of trees (oak, ash,elm) has shown the interrelationship between thedevelopment of the plant communities, the soil andthe water. The project to resolve the water regime ofthis region started in 1963, after the flooding in thecity of Zagreb, when the course of the Sava Riverstarted be straightened and embanked, as did itstributaries in the area of Central Posavina; reliefchannels were constructed (Lonja-Strug, Sava-Odra, Zelina-Èesma). Along with these majorchannels, a whole series of smaller channels andditches were constructed, which also had a majoreffect on the water regime. Apart from the channels,the great number of public and forest roads built inthe period also had a great impact.All these works distorted the previous natural regimeof flooding of the area, and the area began to be usedas a retention basin, i.e., an area into which waterwas released in a controlled way for the purpose ofprotecting the flooding of areas to be protected. Thecreation of this retention area considerably disturbedthe previous dynamics of inflow, standing anddrainage of the flood waters, and over time therewere changes in the structure of the soil, with an evergreater accumulation of detrimental substances. Theconsequences of the long retention of the water inthe retention field was the heating of the water andthe loss of oxygen in the water and soil, which,alongside the previously mentioned concentration ofdetrimental substances in the soil, led to the decayand death of the roots.By the watercourse engineering works alreadymentioned, the water regime was deranged the restof the year, in the most important segment, that is,the level of the underground waters, which are mostimportant for the continued survival of stands. Thedropping of the levels of the underground waters isthe main reason for the mortalitz of the stands in thisarea, and it is estimated that since 1963, some500,000 cubic metres of timber stocks have beenaffected by mortality.Apart from the development and survival of the oldstands there are big problems in the area with theregeneration of the stands. Further standing of thewater in the retention field during spring and in the





podignute u svrhu zaštite pomlaðenih površina oddivljaèi i stoke.Iz izlo�enog mo�emo zakljuèiti da je gospodarenjesastojinama znatno ote�ano, od nemoguænostiplaniranja sjeèa i uzgojnih radova u "Osnovamagospodarenja", do provoðenja propisanih radova.Ovo potvrðuje i intenzivnim sušenjem uvjetovanapotreba promjene propisa "Osnova gospodarenja" utijeku jednog polurazdoblja, tako da su za podruèjeG.J. "Josip Kozarac" u tijeku polurazdoblja izraðenedvije izvanredne revizije.U iduæem razdoblju mogu se oèekivati velikiproblemi, uzrokovani sušenjem stabala, a nastat æe iproblem obnove, pogotovo sastojina ureðajnograzreda jasena i sastojina lu�njaka u kojim je jaèezastupljen jasen.Sušenjem uzrokovano smanjenje kakvoæe drvnihsortimenata, smanjit æe prihode, a problemi u obnovidodatno æe poveæati troškove gospodarenja ovimsastojinama.Svi ovi problemi evidentirani su i u ostalim nizinskimšumama na podruèju Uprave šuma Podru�nicaZagreb, od kojih istièemo G. J. "�utica" na podruèjuŠumarije Novoselec, te G. J. "Turopoljski lug" napodruèju Šumarije Velika Gorica.Sve podrobnije informacije o sastojinama napodruèju Uprave šuma Podru�nica Zagreb mo�etedobiti na Web stranici / http://www.zagreb.hrsume.hrUprave šuma Podru�nica Zagreb.

summer period means that the seed rots and decays,and the shoots and young trees in the stands, whichare in the process of regeneration, even in those inwhich the initial phase of regeneration has beencompleted, and the final cut has been accomplished.In the winter period, when the areas freeze, a newproblem arises; the ice takes hold of the youngplants, and if there is a rise in the level of the water, itwill rip them from the soil, and if the waters drop, thepressure of the sinking ice will lead to the youngplants being damaged and broken.Apart from this kind of damage, ice does damage bybreaking the fences put up to protect the regeneratedarea from domestic livestock and game.From all this we can conclude that management ofthe stands is made much more difficult; from theimpossibility of planning cuts and silvicultureoperations in the General Management Plan, to theimplementation of such works as have beenprescribed. This is also confirmed by the need tochange, because of the intensive withering, theregulations of the Management Plan during a singlehalf-period, in such a way that for the area of theJosip Kozarac area, during a half-period, twoextraordinary reviews were made. In the comingperiod it can be expected that there will be bigproblems brought about by the dying of trees, and theproblem of regeneration, particularly of themanagement class of ash, and of stands of oak inwhich ash also figures in a major way.The reduction in the quality of the timber broughtabout by mortality will lead to reduction in revenue,and problems in regeneration will put up the costs ofmanaging these stands.All these problems are recorded for the other lowlandforests in the area of the Forest AdministrationZagreb Branch, of which we could refer particularly tothe �utica Management Unit in the area of theNovoselec Forest Unit, and the Turopoljski lugManagement Unit in the area of the Velika GoricaForest Unit.

All further information about stands in the area of theForestAdministration Zagreb Branch can be found athttp://zagreb.hrsume.hr.

Dubravko Janeš, dipl. ing. šum.Hrvatske šume d.o.o.

Slu�ba za Ureðivanje šumaPodru�nica Zagreb,

Ul. Vladimira Nazora 7, 10000 Zagreb




23

NIZ

INS

KE

ŠU

ME

mr.sp

. Tih

om

irP

ejn

ovi

æH

rvats

kešu

me

d.o

.o.

Podru

�nic

aS

isak

Slu

�ba

zaU

reðiv

anje

šum

aR

unja

nin

ova

12,44000

Sis

ak

Upra

vašu

ma

Podru

�nic

aS

isak





LO

WL

AN

DF

OR

ES

TS

Sis

ak

Fore

stA

dm

inis

tratio

n



mr.sp

.Tih

om

irP

ejn

ovi

æH

rvats

kešu

me

d.o

.o.

Podru

�nic

aS

isak

Slu

�ba

zaU

reðiv

anje

šum

aR

unja

nin

ova

12,44000

Sis

ak


25

ZAGREBAÈKA ŠKOLAUZGAJANJA ŠUMA IGOSPODARENJE NIZINSKIMŠUMAMA

UVOD

ŠUMARSTVO, UZGAJANJE ŠUMA,GOSPODARENJE ŠUMOM

Èesto se prigovara šumarima kako svojimpostupcima »krèe« šumu, »uništavaju« stabla, nepostupaju »ekološki«, tra�i se zaštita šuma odšumara i sl. Pri tome se zaboravlja èinjenica da jeHrvatska jedna od najbogatijih europskih zemalja poprirodnim šumama. Naime, pribli�no 95% našihšuma je prirodnoga karaktera. To znaèi da su nastaleprirodno i da se prirodno razvijaju. Izmjenageneracija teèe u skladu s prirodnim naèelima.Prirodan naèin njihova postanka, prirodnoststrukture, stupanj biološke raznolikosti, ekološka isocijalna vrijednost tome takoðer govore u prilog.Postavlja se pitanje kako je moguæa takva slika našihšuma kad znamo da su veæinom gospodarskogakaraktera. Istodobno, kako je moguæe da je površinašuma u Hrvatskoj i unatoè gospodarenju ostalagotovo nepromijenjena u posljednjih stotinjakgodina? Odgovori su sa�eti u èinjenici da ješumarstvo u Hrvatskoj tradicionalno ustrojeno premanaèelima prirodnoga pristupa šumskom ekosustavu.Taj se pristup gotovo dva i pol stoljeæa razvija podnazivom Zagrebaèka škola uzgajanja šuma iprimjenjuje se u svim, pa i u nizinskim šumama.Svrha je ovoga èlanka razjasniti što je Zagrebaèkaškola uzgajanja šuma i kako se njezina naèelaprimjenjuju u praksi gospodarenja nizinskimšumama. Šume u parku prirode Lonjsko polje dobarsu primjer za to, s obzirom na èinjenicu da je u njimaradio jedan od najznaèajnijih predstavnika te škole,veliki hrvatski šumar i knji�evnik Josip Kozarac.

Objasnit æemo na poèetku tri pojma koji su znaèajniza razumijevanje teksta: šumarstvo, uzgajanje šumai gospodarenje šumom. Treba napomenuti da se veæiz toga mo�e podosta zakljuèiti o pristupu hrvatskogašumarstva šumskom ekosustavu.Šumarstvo je znanost, struka i umijeæe gospodarenjai oèuvanja šuma i staništa, odnosno èitavogašumskog ekosustava za trajnu dobrobit društva,okoliša i privrede. Ono se brine o uravnote�enom ipotrajnom gospodarenju šumama i drvnim zalihama,

THE ZAGREB SCHOOL OFSILVICULTURE AND THEMANAGEMENT OF LOWLANDFORESTS

INTRODUCTION

FORESTRY SILVICULTURE FORESTMANAGEMENT

There are frequently expressed criticisms of forestryworkers who, during their procedures, “clear” thewoods and do not behave “ecologically”, whileprotection of the forests against the foresters issought, and so on. But the critics, the while, losesight of the fact that Croatia is one of the richest ofEuropean countries in terms of natural forests.About 95% of all our forests are of a naturalcharacter. In other words, they were created andhave developed naturally. The alternation ofgenerations is carried out in accordance with naturalprinciples. The natural manner of their genesis, thenaturalness of the structure, the degree of biologicaldiversity, and the ecological and social value arealso witnesses to this.The question arises as to how this kind of image ofour forests is possible when they are mostlycommercial in character. At the same time, how is itpossible for the area of the woods in Croatia, even inconjunction with management, to have remainedalmost unchanged in the last hundred years or so?The answers are summed up in the fact that forestryin Croatia is traditionally organised according to theprinciples of a natural approach to the forestecosystem. This approach has developed for almosttwo and a half centuries under the name of the“Zagreb School of Silviculture” and is applied in allthe woods, including those in the lowlands. Theobjective of this paper is to explain what the “ZagrebSchool of Silviculture” is, and how its principles areemployed in the practice of managing the lowlandforests. The forests within Lonjsko Polje Nature Parkare a good example of this, because of the fact thatin them once worked one of the most importantrepresentatives of the school, that great Croatianforester and writer Josip Kozarac.

To begin with we shall explain three concepts thatare important for the understanding of this article:forestry, silviculture and forest management. Itshould be said that from this it will already bepossible to draw conclusions about the approach ofthe Croatian forestry to the forest ecosystem.Forestry is the science, profession and art ofmanaging and conserving forests and habitats, thatis, the whole of the forest ecosystem, for the lastingbenefit of society, the environment and theeconomy. It is concerned with a balanced andenduring management of the forest and timberreserves, maximal yields and optimal regeneration,





o najveæim prinosima i najboljem pomlaðivanju, otrajnoj stabilnosti šumskih ekosustava, a istodobno obujnom �ivotinjskom svijetu, obilnim i trajnimprièuvama pitke vode, privlaènom i rekreacijskomokolišu kako u prirodnim tako i u urbanim sredinamate o raznovrsnim uslugama i proizvodima.Uzgajanje šuma je znanstvena i struèna disciplinakoja se bavi osnivanjem, njegom i pomlaðivanjemšumskih sastojina kako bi najbolje i trajno ispunjavalegospodarske i opæekorisne funkcije. Uzgajanje šumaizuèava procese i šumskouzgojne postupke kojima jeu najkraæem razdoblju, uz što manje troškove ioèuvanje staništa, moguæe osnovati, podiæi teoblikovati šumsku sastojinu koja æe najpovoljnije itrajno pru�ati gospodarske, ekološke i socijalneblagodati.Primjenjujuæi šumskouzgojne postupke ostvarujemogospodarenje šumom, odnosno postizanje iodr�avanje ciljeva gospodarenja. �ivot šume odnastanka do zrelosti i konaène sjeèe, kao i istodobnaizmjena generacija moraju teæi u skladu s prirodnimzakonitostima, onako kako teku u »najprirodnijojšumi«, tj. prašumi. Šumskouzgojni postupci trebajupodupirati i usmjeravati prirodni razvoj šuma uznajveæe uva�avanje svih procesa koji se zbivaju uinaèe slo�enu i osjetljivu šumskom ekosustavu. Jer»

(Leibundgut, 1959.).

U skladu s tim izra�eni su i današnji strateški ciljevigospodarenja šumama u Hrvatskoj:1. osiguranje stabilnosti ekosustava2. odr�avanje i poboljšavanje opæekorisnih funkcija

šuma3. potrajno gospodarenje4. iskorištavanje šuma i šumskih zemljišta na naèin i

u takvoj mjeri da se odr�ava njihova biološkaraznol ikost , produkt ivnost , sposobnostobnavljanja, vitalnost i potencijal

5. ispunjavanje, sada i u buduænosti, bitnihgospodarskih, ekoloških i socijalnih funkcija nalokalnoj i globalnoj razini, a da to ne šteti drugimekosustavima.

Kako vidimo, u strateškim ciljevima gospodarenjašumama u Hrvatskoj naglašeno je oèuvanješumskoga ekosustava i njegovo potrajnoiskorištavanje. Posljednje dvije toèke identiène sudefiniciji pojma potrajno gospodarenje šumama(istozn. odr�ivo gospodarenje šumama).Nijedan od spomenutih ciljeva nije dar prirode i nemo�e se postiæi ako se šuma prepusti samospontanim, prirodnim procesima (Matiæ i dr., 2003.,Pintariæ, 1969.). Ti se ciljevi mogu postiæi i, što je još

najbolji je onaj šumar koji zna kako pustiti prirodu daide svojim ciljevima«

in conjunction with the lasting stability of forestecosystems, taking account at the same time of theflourishing animal world, the abundant and lastingreserves of potable water, an attractive andrecreational surrounding but in natural and in urbanmilieus, and also concerned with various productsand services.Silviculture is a scientific and professional disciplineconcerned with the establishment, care andregeneration of forest vegetation units [stands], insuch a way that that they permanently and optimallyfulfil their economic and general use functions.Silviculture studies the processes and forest-cultivation procedures that will, in the shortest periodof time, with the lowest costs and with theconservation of the habitats, allow a forestvegetation unit to be established, raised and shapedto provide various economic, ecological and socialbenefits, optimally and lastingly.Through the implementation of silvicultureprocedures, we put forest management intopractice, that is achieve and maintain the objectivesof forest management. The life of the forest, fromcreation to maturity and final felling, and thesimultaneous succession of generations, mustunfold in accordance with the laws of nature, in thesame way that it unfolds in the most natural forest ofall, in a virgin forest, that is. Silviculture proceduresshould support and channel the naturaldevelopment of the forests, with the maximumdegree of respect being paid to all the process thatunfold in the actually very complex and sensitiveforest ecosystem. Because

(Leibundgut 1959).In accordance with this, today's strategic objects forforest management in Croatia have been expressedas follows:1. ensuring the stability of the ecosystem(s)2. maintaining and improving the general use

functions of the forests3. lasting management4. use of forests and forest lands in a manner and to

such an extent that their biological diversity,productivity, capacity to regenerate, vitality andpotential are maintained

5. meeting, now and in the future, essentialeconomic, ecological and social needs at the localand global level, without detriment thereby toother ecosystems.

As we can see, in the strategic objectives of forestmanagement in Croatia, the preservation of the forestecosystem and its lasting use are stressed. The lasttwo points are identification to the definition of theconcept of lasting forest management (or sustainableforest management, which is the same thing).None of these objectives is a gift of nature, andcannot be achieved only if the forest is leftexclusively to spontaneous natural processes(Matiæ et al, 2003; Pintariæ, 1969). These objectivescan be achieved, and what is even more important,

“the best forester is hewho knows how to let nature go on towards its ownobjectives”




27

bitnije, trajno odr�ati jedino ako se u šumi obavljajušumskouzgojni postupci. Dakle, šuma ne mo�enajbolje i trajno ispunjavati ekološke, socijalne igospodarske funkcije bez šumskoga gospodarenja.Meðutim, šumsko gospodarenje mora biti usmjerenona postizanje i trajno odr�avanje tih funkcija.

Razlikuju se prirodni i umjetni pristup uzgajanju šuma(Korpel, 1991.). Prirodna (tradicionalna, klasièna)škola uzgajanja šuma gleda na šumu kao naekosustav. To znaèi da se u prirodnom pristupu pazina sve sastavnice šumskoga ekosustava.Predstavnici te škole zagovaraju uzgajanje i trajnooèuvanje prirodnih šuma. Protiv su uporabe«stranih» vrsta drveæa. Zagovaraju prilagodbušumskouzgojnih postupaka prirodnome razvojušume i prirodno pomlaðivanje (Korpel i Saniga,1995.; Otto, 1998.). Cil jevi gospodarenjaobuhvaæaju, osim gospodarskoga, i opæekorisniaspekt (ekološke i socijalne funkcije šume). Danas jeklasièna škola uzgajanja šuma prepoznatljiva podnazivom ili

(prirodi blisko uzgajanje šuma, prirodnouzgajanje šuma, uzgajanje prirodnih šuma).Umjetnu (tehnièku) školu uzgajanja šumaobilje�avaju: pristup šumi kao gospodarskomobjektu, šumskouzgojni postupci prilagoðeni jedinogospodarskim ciljevima, pomlaðivanje èistimsjeèama, umjetno pomlaðivanje. Zagovornici te školenisu protiv uporabe »stranih« vrsta drveæa ako tonala�u zakoni tr�išta. Zala�u se za uzgajanje onihvrsta drveæa koje se u danom trenutku isplate. Ostalesastavnice šumskoga ekosustava uzimaju se u obzirsamo ako se njihovom prodajom mo�e ostvariti dobit.Usporedit æemo dva primjera iz njemaèkogašumarstva 19. stoljeæa, iz kojih se vide opisanipristupi uzgajanju šuma i šumarstvu uopæe. U svomud�beniku o uzgajanju šuma, godine 1817., HeinrichCotta, prvi i dugogodišnji ravnatelj Šumarskeakademije u Tharandtu, piše: »

. Bilo je to dobakada je u Njemaèkoj vladao koncept koji jepoistovjeæivao šumarstvo s poljoprivednomproizvodnjom: èista sjeèa - sadnja - èista sjeèa (�etvasjetva �etva). Opæekorisne uloge šume (tlo, voda,klima, kisik, šumski plodovi, ljekovito bilje, gljive,�ivotinje, zaštita od erozija, vjetra, lavina,zdravstvena uloga, estetska uloga …) nisu uzimaneu obzir. Zbog takvoga je pristupa šumarstvu u veæemdijelu Europe (ne i u Hrvatskoj!) obavljena pretvorbaautohtonih prirodnih šuma u šume tada rentabilnijih

ZAGREBAÈKAŠKOLAUZGAJANJAŠUMA

close-to-nature silviculture naturalisticsilviculture

…uzgajanje šuma jeslièno poljoprivredi. Ono izuèava kako osnovati injegovati šumu te iskoristiti drvo«

maintained indefinitely only if silviculture proceduresare carried out in the forest. A forest, that is, cannotoptimally and permanently perform its ecological,social and economic functions without forestmanagement. However, forest management has tobe directed towards the achievement and lastingmaintenance of these functions.

There are differences between the natural and theartificial approaches to silviculture (Korpel, 1991).The natural (traditional, classical) school ofsilviculture looks upon the forest as an ecosystem.This means that in the natural approach, care istaken of all the components of the forest ecosystem.Proponents of this school champion the cultivationand permanent conservation of natural forests. Theyare against the use of foreign species of trees. Theystand up for the adjustment of silvicultureprocedures to the natural development of the forestand natural regeneration (Korpel and Saniga, 1995;Otto, 1998). The objectives of management include,as well as the economic, the general use aspect aswell (the ecological and social functions of theforest). Today the classical school of silviculture isidentifiable by the namesor .The artificial or technical silviculture school ischaracterised by: an approach to the forest as to aneconomic facility, silviculture procedures adjustedexclusively to economic goals, regeneration byclear-cutting, artificial regeneration. Those whostand for this school are not against the use offoreign species of tree, if the laws of the market insistupon it. They champion the culture of those speciesof tree that are profitable at the current moment.Other vegetation units of the forest ecosystem aretaken into consideration only if a profit can be madeby the sale of them.We shall compare two examples from Germanforestry of the 19th century, from which theapproaches to silviculture and forestry in generalcan be perceived. In his silviculture manual of 1817,Heinrich Cotta, the first and a long-time director ofthe Forestry Academy in Tharandt writes“

”. This was thetime when Germany was dominated by the conceptthat equated forestry with agricultural production:clear-cutting planting clear-cutting (harvestingsowing harvesting). The general use roles of theforest (to do with the soil, water, climate, oxygen,forest fruits, medicinal herbs, fungi, animals,protection against erosion, winds, avalanches, therole in the preservation of health, and the aestheticrole) were not taken into consideration. Because ofthis kind of approach, in most of Europe (but not inCroatia) there was a transformation of theindigenous natural forests into forests of species oftrees that were profitable at the time. Apart fromthat, through sudden exploitation, the naturaldevelopment of the forests was very largely

THE ZAGREB SCHOOL OF SILVICULTURE

close-to-nature silviculturenaturalistic silviculture

silviculture is like agriculture. It studies how toestablish, tend and make use of trees





vrsta drveæa. Osim toga, naglim iskorištavanjemporemeæen je u veæoj mjeri prirodni razvoj šuma.Nastale su »umjetne šume«, odnosno šumskekulture koje i danas pokrivaju dobar dio šumskihzemljišta. S druge strane, Karl Gayer, profesoruzgajanja šuma u Münchenu, razvijao je misao omješovitim šumama raznolike strukture koje seprirodno pomlaðuju. Naglašavao je kako je bitno nadtlom saèuvati stalan šumski pokrov i iskljuèiti èistesjeèe. Njegov je pristup bio: »

.Zagrebaèka škola uzgajanja šuma dio je prirodneškole uzgajanja šuma. Rezultat je gotovo dva i polstol jeæa dugoga cjelokupnog usmjerenja,znanstvenoga i obrazovnoga pristupa te praktiènogapostupanja u gospodarenju hrvatskim šumama, uzozakonjenja takvih spoznaja i aktivnosti.

Njezine su temeljne znaèajke:- gospodarenje prirodnim šumama- potrajnost u gospodarenju šumama- pomlaðivanje pod zastorom krošanja- prirodno pomlaðivanje- umjetno pomlaðivanje po naèelima prirodnoga- odr�anje strukture i stabilnosti šume njegom- šumskouzgojni postupci obavljaju se tako da

usmjeravaju razvoj sastojine prema naèelimarazvoja prašume, ali na temelju kriterija kojiproizlaze iz ciljeva gospodarenja.

Povijest Zagrebaèke škole uzgajanja šumauklopljena je u razvoj šumarske struke i znanosti uHrvatskoj. Prema Matiæu i dr. (2001.) i Klepcu (1998.,1997.), svemu je prethodilo osnivanje i ureðenjeVojne krajine (1702. - 1746.) te zapovijed MarijeTerezije godine 1762. kojom je zabranila izvozhrastovine za brodogradnju iz svoje zemlje. Naredilaje podroban opis, premjer i izradu karata šuma,sastavljanje šumskoga reda (danas osnovagospodarenja) te postavljanje struènoga osoblja zagospodarenje šumama. Zato su od 1764. do 1765.izraðene prve gospodarske osnove s kartama iosnovane prve šumarije. Šumarska slu�ba bila jeureðena uredbama sa zakonskom snagom izakonima o šumama. Šumarski struènjaci najprije suse školovali na Šumarskoj akademiji u Mariabrunnu.Godine 1898. u Zagrebu je osnovana Šumarskaakademija, preteèa današnjega Šumarskogafakulteta. Time je zapoèela visokoškolska nastavašumarstva u Hrvatskoj. Tako je na naèelimaZagrebaèke škole uzgajanja šuma do danasobrazovano 106 naraštaja in�enjera šumarstva.Naèelo potrajnosti u gospodarenju šumama poznatoje od 18. stoljeæa i do danas je ostalo jedini pravi

prihvatimo da je prirodanaš najbolji uèitelj«

distorted. Artificial forests were created, that isforest cultures that today cover a large part of theforest land. On the other hand, Karl Gayer, professorof silviculture in Munich, developed a way of thinkingabout mixed forests of a varied structure that wouldbe naturally regenerated. He stressed that it wasessential to maintain a permanent forest cover overthe ground and to avoid clear-cutting. His approachwas: “

”.The Zagreb Silviculture School is part of the naturalschool of silviculture. It is the outcome of an almosttwo and a half century long overall orientation, of ascientific and educational approach, and practicalprocedure in the management of Croatian forests,and the legislation of such cognition and activity.

The fundamental characteristics of it are:

- managing natural forests- persistence in managing the forests- regeneration under the canopy screen- natural regeneration- artificial regeneration along the lines of natural

regeneration- maintenance of forest structure and stability by

care- silviculture procedures are carried out in such a

way that they direct the development of avegetation unit (a stand) after the principles ofthe virgin forest, but pursuant to criteria thatderive from management goals.

The history of the Zagreb Silviculture School fits inwith the development of the forestry profession andforestry science in Croatia. According to Matiæ et al(2001) and Klepac (1998, 1997), this was allpreceded by the foundation and organisation of theVojna Krajina, the Military Border (1702-1746) andthe edict of Maria Theresa of 1762 forbidding theexport of oak for shipbuilding outside the country.The empress ordered a detailed description, surveyand the elaboration of forest maps, the compositionof the “forest order” (today the forest managementplan) and the appointment of qualified men tomanage the forests. That is why in the 1764-1765the first economic plans with maps were drawn upand the first forest management units were founded.The forest service was organised by edicts with theeffect of legislation as well as by Forest Statutes.Forestry experts were first of all educated at theForestry Academy in Mariabrunn. In 1898 theForestry Academy was established in Zagreb, theforerunner of today's Forestry Faculty. This startedthe tertiary level teaching of forestry in Croatia.Thus 106 generations of forestry engineers havebeen trained to date along the principles of theZagreb Silviculture School.The principle of sustainability in forest managementhas been known since the 19th century, and hasremained the only real example of sustainabledevelopment to the present day (Glavac 1999). In

let us accept the fact that nature is our bestteacher




29

primjer odr�ivoga razvoja (Glavaè, 1999.). UHrvatskoj je to naèelo uvedeno veæ 1769. kada jeobjavljena »Zakonska uredba o šumama«. Ta seuredba smatra prvim hrvatskim šumarskim zakonom,prvom instrukcijom za ureðivanje šuma i prvimud�benikom šumarstva (Meštroviæ, 1995.).Prema uredbi bila je propisana metoda razdiobešuma na godišnje sjeèine. Metoda se sastoji u tomeda se površina šume razdijeli na onoliko podjednakihdijelova (sjeèina) koliko ophodnja (vijek šume nanekoj površini od nastanka do zrelosti) broji godina.Svake se godine sijeèe jedan dio. Tako je na koncuophodnje cijela šuma posjeèena. Sjeèa je moglaponovno zapoèeti na istome mjestu kao na poèetkuophodnje (Klepac, 1998.). Naèela te uredbeugraðena su u prve zakone o šumama (1852.,1894.), na temelju kojih je bilo organizirano šumskogospodarenje.Godine 1846. osnovana je staleška udruga Hrvatsko-slavonsko šumarsko društvo, preteèa današnjegaHrvatskoga šumarskog društva. Na prvoj skupštiniraspravljalo se o temi Kako treba gospodariti u starimhrasticima prašumske strukture da bi se kvalitetnopomladili?

Slika 1. Shematizirani prikaz potrajnoga šumskogagospodarenja: šuma površine 1000 ha podijeljena jena 20 jednakih dijelova jer ophodnja traje 20 godina.Svake se godine sijeèe 1/20 šume, a na krajuophodnje sjeèa se vrati na mjesto odakle je poèela.Do danas je taj sustav u Hrvatskoj usavršen uvišenamjensko progresivno potrajno gospodarenje.

Croatia this was introduced as far back as 1769when the Legislative Ordinance [Edict] Concerningthe Forests was published. This ordinance isconsidered the first Croatian forestry law, the firstset of regulations for managing the forests, and thefirst forestry manual (Mestrovic, 1995).According to this ordinance, the method of dividingthe forest for annual felling was prescribed. Thismethod consists of the area of the forest beingdivided into as many equal parts (felling areas) asthe rotation (the age of a forest in some area fromorigin to maturity) has years. Each year, one part isfelled. Thus at the end of the rotation, the whole ofthe forest has been felled. Felling can berecommenced in the same place as at the beginningof the rotation (Klepac 1998). The principles of thisordinance were incorporated into the first ForestLaws (1852, 1895), pursuant to which forestmanagement was organised.In 1847 the professional association called theCroatian and Slavonian Forestry Association wasfounded; this was the forerunner of today's CroatianForestry Association. At the first annual assembly,the topic of discussion was: How should old oakstands of a virgin forest structure be managed insuch a way as to ensure high quality regeneration?

Figure 1. Diagrammatic view of sustainable forestmanagement: a forest of an area of 1000 ha isdivided into 20 equal parts, because a rotationcomes to 20 years. Each year one twentieth of theforest is felled, and at the end of the rotation thefelling returns to the spot it started off from. By thepresent age, this system has been perfect in Croatiainto multi-purpose progressive sustainablemanagement.





Godine 1852. donesen je prvi zakon o šumama. Udrugom èlanku toga zakona piše »

. U devetom èlanku stoji da »

.Tim je zakonom naglašena potreba oèuvanjapovršine šuma i šumskog zemljišta, a posebicepotreba da se stanje šuma poboljša. Tako jeutemeljeno višenamjensko progresivno potrajnogospodarenje. Dodajmo tome i 1894. godinu kada jedonesen sljedeæi zakon o šumama. U njemu jeponovno istaknuto naèelo potrajnosti jer u treæemèlanku piše: »u šumah obæinskih ima se zavestipotrajno gospodarenje (Nachaltiger Betreib)«.

I danas su šume i šumska zemljišta prepoznati kaodobra od interesa za Hrvatsku, pa imaju njezinuosobitu zaštitu (prema èlanku 52. Ustava RepublikeHrvatske). U prvom èlanku Zakona o šumama šume išumska zemljišta definirani su kao specifiènoprirodno bogatstvo te s opæekorisnim funkcijamašuma èine posebne prirodne i gospodarske uvjeterada.

Nizinske šume Hrvatske prostiru se sjeverno odKarlovca, uglavnom u prostoru omeðenom rijekama:Dravom na sjeveru, Dunavom na istoku i Savom najugu, u nizinskom (planarnom) vegetacijskom pojasu,na nadmorskim visinama izmeðu 80 i 150 metara.Površina nizinskih šuma zauzima pribli�no 290 000ha. Od toga 205 000 ha pokrivaju šume hrastalu�njaka, 27 000 šume poljskog jasena, 17 000 šumecrne johe, 11 500 ha šume domaæih vrba, ponajprijebijele vrbe, 6000 ha šume domaæih topola, ponajprijebijele i crne topole, a 16 000 ha šumske kulture iplanta�e euro-amerièkih topola dok su na 6500 hašume ostalih vrsta drveæa (Vukeliæ i Rauš, 2001.).Temeljni je ekološki èimbenik, koji regulirafunkcioniranje nizinskih šumskih ekosustava, voda,bilo poplavna (znaèajna za šume vrba i topola),podzemna (znaèajna za šume hrasta lu�njaka) iliobje (znaèajno za šume poljskog jasena i crne johe).Postanak i razvoj nizinskih šuma naèelno se dogaðaprema Slici 2. Obešumljenu, golu površinu najprijenaseljavaju pionirske vrste drveæa koje oblikujupionirsku šumu. U posavskim šumama najva�nijipionir je poljski jasen ( ). Podzastorom krošanja pionirske šume mijenjaju seekološke prilike u usporedbi s golom površinom:nema mikroklimatskih ekstrema, nema suše, tlo jepod zasjenom, kemizam prostirke i humusnoga slojadrugaèiji su nego na goloj površini…

da se nijednošumsko zemljište ne smije oduzeti niti pretvoriti udrugu kulturu« se šumene samo trebaju uzdr�avati nego valja neprestanoprimjerenim naèinom njihovo stanje poboljšavati«

Fraxinus angustifolia

NAÈELAGOSPODARENJANIZINSKIM ŠUMAMA

In 1852 the first Forests Act was passed. Article 2says that “

”.Article 9 says that “

” This law highlightsthe need to preserve the forest areas and the forestland, and in particular the need to improve thecondition of the forests. Thus the foundations wereset for multi-purpose progressive sustainablemanagement were laid. We might add to this that in1894 the next Forests Law was passed. It also, onceagain, highlighted the principle of sustainability, forArticle 3 writes: “in the public forests sustainablemanagement (nachaltiger Betreib) is to beintroduced.”

Today too the forests and forests lands arerecognised as assets that are of interest to the state,and which have the particular protection of the state(according to Article 52 of the Constitution of theRepublic of Croatia). In Article 1 of the Forests Law,the forests and forest lands are defined as a specifickind of natural riches, and with their general usefunctions of the forests, constitute special naturaland economic conditions of work.

The lowland forests of Croatia stretch from north ofKarlovac, mainly in the area bordered by the riversDrava in the north, Danube in the east and the Savain the south, in the lowland or plain vegetation zone,at heights above sea level of 80 to 150 m.The area of the lowland forests comes to about290,000 hectares. Of these, 205,000 ha arecommon oak forests, 27,000 ha narrow-leaved ash,17,000 forests of black alder, 11,500 forests ofwillows, mainly white willows, 6,000 ha of forests ofdomestic poplars, mainly white and black poplars,16,000 ha are covered with forest cultures andplantations of European and American poplars, and6,500 ha are forests of other kinds of trees (Vukeliæand Raus, 2001).The fundamental ecological factor that regulates thefunctioning of the lowland forest ecosystems iswater, whether floodwater (important for the poplarand willow woods), underground water (importantfor common oak forests) or both (important for theash and alder forests).The origin and development of lowland forests inprinciple follows a cycle depicted in Figure 2. Adeforested bare area is first of all colonised bypioneering kinds of tree that form the pioneeringforest. In the forests of Posavina the most importantpioneer is , the narrow-leavedash. Under the canopy of the treetops of thepioneering forest, the ecological conditions changeas compared with those of the forest-free area.There are no such microclimatic extremes, there areno droughts, the ground is shaded, and the

no piece of forest land may beappropriated or turned into some other kind of crop

the forests need not onlymaintaining but, through some appropriate manner,their condition needs improving.

Fraxinus angustifolia

THE PRINCIPLES FOR MANAGING THELOWLAND FORESTS




31

Slika 2. Shema sukcesije nizinskih šuma snaznakama naèina pomlaðivanja, vrstama šumskihsastojina i staništaTakvi uvjeti više ne pogoduju pomlaðivanju pionirskihvrsta, nego pomlaðivanju polusvjetloljubivih,polusjenoljubivih i sjenoljubivih vrsta drveæa. Tako

chemistry of the cover and the humus layer aredifferent than they are on the bare surface…

Adiagrammatic sketch of the succession inthe lowland forests, with indications of the manner ofregeneration, the kinds of forest vegetation units,and habitats.

Figure 2.





postupno nastaje prijelazna šuma. Ako se �elizaustaviti prirodni tijek sukcesije i ostati pri pionirskojšumi, primijenit æe se zato èista sjeèa. Èistom sjeèomuklanjamo odjednom sva stara stabla. Njome seoponašaju ekološki uvjeti obešumljenoga staništa nakojemu se ponovno oblikuje pionirska šuma.Treba napomenuti kako su èiste sjeèe u HrvatskojZakonom o šumama zabranjene. Inaèe je obvezadobroga šumskoga gospodara usmjeravati šumskiekosustav prema progresivnoj sukcesiji, a ona se nemo�e postiæi èistom sjeèom. Èista sjeèa degradirastanište i zaustavlja prirodni tijek progresiješumskoga ekosustava.Prijelazna šuma je poveznica izmeðu pionirske ikonaène šume. U njoj se pod krošnjama pionirskihvrsta drveæa (poljskog jasena, crne johe, vrba,topola) pomlaðuju brijestovi, grabovi, javori, lipe,šumske voækarice i vrste konaène šume, poglavitohrast lu�njak ( ). Prijelazna je nizinskašuma, primjerice, miješana šuma poljskoga jasena ihrasta lu�njaka ili poplavna lu�njakova šuma.Konaèna šuma (klimaks-šuma, klimatogena šuma)relativno je ustaljen završetak prirodnoga razvojašumskoga ekosustava. Tvore je konaène(klimatogene) vrste drveæa. U nizinskim šumamakonaèna je vrsta drveæa hrast lu�njak, a konaèni oblikšume je miješana šuma hrasta lu�njaka i obiènogagraba. Meðutim, i taj je ekosustav dinamièan. Bitno jeshvatiti da je svaka šuma »�ivi organizam« kojinastaje, raste, stari, odumire, raspada se i istodobnopomlaðuje po odreðenim zakonitostima. Zadatak ješumara prilagoditi se tim procesima po naèelimadobrih gospodara.Pomlaðivanje prijelazne i konaène šume zbiva sepod zastorom krošanja starih stabala (Slika 3).Jedino se tako uspijeva stvoriti i odr�ati novageneracija šume. Naime, nju tvore vrste drveæa kojenemaju znaèajke pionirskih vrsta, posebice gledesvjetla. To je razlog zbog kojega se prijelazne ikonaène šume pomlaðuju pod zastorom krošanjastarih stabala, postupkom poznatim pod nazivomprirodno pomlaðivanje oplodnim sjeèama. Oplodnimsjeèama se postupno, u 2 - 3 navrata, sijeku starastabla. Sjekovi se zovu pripremni, naplodni i dovršni.U hrastovim se šumama sjekovi obavljaju u pribli�nimvremenskim razmacima, svake 2 - 3 godine, pa èitavpostupak pomlaðivanja mo�e potrajati do 8 godina.Tim se sjekovima stara stabla potièu na pojaèani urodsjemena, tlo se naploðuje tim sjemenom, ono klija, anova generacija raste u skladu s potrebama zasvjetlom koje se dozira uz pomoæ oplodnih sjeèa.Tako se na najbezbolniji i najprirodniji naèin obavljapostupna izmjena generacija šume, bez šoka idegradacije staništa.

Quercus robur

Such conditions no longer favour the regeneration ofthe pioneering species, rather the regeneration ofspecies of trees that favour shady, semi-shady andlight habitats. Thus a transitional kind of forestcomes into being. This is the reason why, if onewants to halt the natural course of the successionand stick with the pioneering forest, clear-cutting isused. Clear-cutting removes at once all the oldtrees. This is used to imitate the ecologicalconditions of the deforested habitat in which thepioneering forest can once again be formed.It should be mentioned here that pure felling isforbidden in the Croatian Forests Law. It is actuallythe obligation of a good forest steward to direct theforest ecosystem towards the progressivesuccession, and this cannot be achieved with theclear-cutting. Clear cutting degrades a habitat andhalts the natural course of the progression of a forestecosystem.A transitional forest is a link between a pioneeringand a climax forest. In it, under the crowns of thepioneering species (narrow-leaved ash, alder,willow, poplar), the regeneration comes in the form ofelms, hornbeams, maples, limes, forest fruit treesand species of the climax forest, particularly thecommon oak, . A transitional lowlandforest, for example, is a mixed forest of narrow-leaved ash and common oak or a riparian commonoak forest.The final or climax forest, the climax forest, is arelatively settled conclusion of the naturaldevelopment of the forest ecosystem. It is made bythe climax (climatogenic) species of tree. In thelowland forest the climax species of tree is thecommon oak, and the climax form of forest is mixedforest of common oak and common hornbeam.However, this ecosystem too is dynamic. It isessential to understand that every forest is a livingorganism that comes into being, grows, ages, diesand decays and is at the same time regeneratedaccording to certain laws. It is the task of the foresterto adjust to these processes according to principlesof good stewardship.Regeneration of the transitional and climax foresttakes place under the canopy of the crowns of the oldtrees (Figure 3). Only in this way is it possible tocreate and maintain the new generation of the forest.For it is made by tree species that do not have thecharacteristics of the pioneering species,particularly with respect to light. This is the reasonwhy the transitional and climax forests arerejuvenated under the cover of the crowns of the oldtrees by the procedure known under the name of thenatural regeneration by regenerative felling. Inregenerative felling, gradually, on two or threeoccasions, the old trees are felled. These cuts arecalled preparatory, seeding and final. In oak foreststhe cuts are carried out in approximate intervals ofevery two to three years, and the whole process ofregeneration can last up to eight years. With suchfellings the old trees are provoked to producerincreased seed, the ground is seeded with theseseeds, the seed sprouts, and the new generation

Quercus robur




33

Slika 3. Proces pomlaðivanja šumske sastojineoplodnim sjeèama: a) izgled sastojine prije poèetkapomlaðivanja; b) izgled sastojine nakon pripremnogasijeka. Njime su razmaknute krošnje i izazvan jepojaèan urod sjemena preostalih, najkvalitetnijihstabala. Istodobno, tim se sijekom stanište pripremaza prihvat i klijanje sjemena; c) sastojina nakonnaplodnoga sijeka. Tim se sijekom dozira svjetlonovoj generaciji koja raste pod krošnjama. Intenzitettoga sijeka ovisi o potrebama za svjetlom novegeneracije; d) nova generacija nakon dovršnogasijeka. Taj sijek se izvodi kada novoj generaciji višene treba zaštita krošanja starih stabala.Treba istaknuti da se ovim naèinom oponaša procespomlaðivanja koji se inaèe dogaða u prašumi, u fazinjezina raspadanja (Prpiæ i Seletkoviæ, 1996.; Korpel,1989.; Leibundgut, 1978.; Matiæ i dr., 1979.). U

grows in line with the needs for light, which isadjusted with the regeneration felling. Thus in themost painless and most natural way, the gradualsuccession of the generations of the forest isachieved, without any shock, without degradation ofthe habitat.

The process of regenerating a forestvegetation unit with seeding cuts: a) the appearanceof a stand before the beginning of regeneration; b)the appearance of a stand after the preparatory cut.This provides greater distance between crowns andan increased production of seed among the other,high quality, trees is stimulated. c) the stand after theregeneration cut. This cut is used to adjust the lightfor the new generation growing beneath the crowns.The intensity of this cut depends on the newgeneration's need for light. d) the new generationafter the final cut. This cut is done when the newgeneration no longer needs the protection of thecanopy of the older trees.

Figure 3.

(a)

(b)

(c)

(d)

prašumi stara stabla postupno odumiru i raspadajuse kada dosegnu svoju fiziološku zrelost. Istodobno,ona zasiju okolnu površinu svojim sjemenom. Procesnjihova raspadanja i istodobnoga nastanka novegeneracije slièan je pomlaðivanju pod zastoromkrošanja u gospodarskim šumama.Naravno da proces prate mnogobrojni problemi.Spomenut æemo najva�nije koji utjeèu na uspjehpomlaðivanja hrasta lu�njaka (Matiæ, 1996.; Matiæ idr., 1979.):

- štetnici i gljivièna oboljenja �ira i mladoga hrasta

It is worth mentioning that this manner copies themanner of regeneration that occurs in the virginforest in the phase of its decay (Prpiæ and Seletkoviæ,1996; Korpel 1989; Leibundgut 1978a; Matiæ et al1979). In the virgin forest the old trees gradually dieoff and decay when they reach their physiologicalmaturity. At the same time, they sow the surroundingarea with their seeds. The process of decay and thesimultaneous creation of a new generation aresimilar to regeneration under a canopy of crowns incommercially managed forests.Of course, the process is associated with many





- nedovoljan urod �ira- vlaga i temperatura tla u fazi klijanja �ira- trajanje proljetne poplave, posebice u fazi

poèetnoga rasta biljèica- intenzitet osvjetljenja biljèica u prvih 3 - 5 godina

razvoja- konkurencija ostalih vrsta drveæa, grmlja i

prizemoga rašæa- stanje populacije štetnika, posebice šumskih

glodavaca- stanje populacije divljih svinja i �irenje.

Mo�e se dogoditi da u tijeku pomlaðivanja nemadovoljno biljaka nove generacije ili èak da novageneracija bude uništena. Zbog toga se slu�imopostupkom sjetve ili sadnje sjemena ili sadnica.Postupak se obavlja jednako kao i prirodnopomlaðivanje. Razlika je u tome što biljke novegeneracije nisu nastale iz sjemena s krošanja starihstabala, nego iz posijanoga ili posaðenoga sjemenaili sadnica.Tijekom �ivota šuma se njeguje. Pod njegom šumapodrazumijevaju se oni uzgojni postupci kojima senastoji stvoriti takva šumska struktura koja æeosiguravati njezinu stabilnost, produktivnost, vitalitet,bioraznolikost i, na kraju �ivota, moguænostkvalitetnoga prirodnog pomlaðivanja.Njegom usmjeravamo razvoj šume u skladu sprirodnim zakonitostima, najbolje iskorištavajuæistanišne uvjete, biološka svojstva i ekološke zahtjevevrsta drveæa. Na taj naèin podupiremo i odr�avamošumu u najboljim strukturnim uvjetima gdje sustabilnost, produktivnost i biološka raznolikosttemeljni pokazatelji optimalnoga stanja. Moguænostprirodnoga pomlaðivanja tako njegovanih šumalogièan je slijed i korak koji vodi njihovoj vjeènosti.Njegom se ne utjeèe toliko na kolièinu koliko nakakvoæu šume (Matiæ i dr., 2003., Leibundgut, 1978.,Lang, 1982., Koestler, 1952., Pintariæ, 1969.).Njega šuma i stabala utemeljena je na èinjenici da jefenotip rezultat genotipa i utjecaja okoliša, odnosnostanišnih uvjeta. Njegom se utjeèe na fenotip istanište. Njome se spontano odabiranje stabala ušumi zamjenjuje odabiranjem temeljenim našumskouzgojnim naèelima. Razlikuju se pozitivno inegativno odabiranje. Negativnim odabiranjemuoèavaju se i uklanjaju sve nepo�eljne jedinke doone dobi kada se poèinju uoèavati stabla buduænosti.Nakon toga prelazi se na postupke pozitivnogaodabiranja kojima se iz šume uklanja ono što ometarazvoj uoèenih stabala buduænosti. Pri tome se moravoditi raèuna da sastojina ne izgubi bitna obilje�ja:prirodnu strukturu, suvislost, proizvodnost,stabilnost, raznolikost i moguænost prirodne obnove(Matiæ i dr., 2003.).

problems. We shall mention a few of the mostimportant that affect the success of regeneratingcommon oak forests (Matic 1996; Matic et al 1979):

- pests and fungal conditions of the acorn andyoung oak

- insufficient yield of acorns- continuation of spring flooding, particularly in

the initial growth phase of the plant- intensity of illumination of the young plant in the

first three to five years of development- competition from other species of trees, bushes

and epigeal growth- state of population of pests, particularly rodents- condition of the population of wild boar and

foraging.

It can happen that during regeneration there are notenough plants of the new generation and even thatthe new generation is destroyed. Because of this theprocedure of sowing or planning seeds or plants isresorted to. The procedure is done in a manneridentical to natural regeneration. The difference isthat the plants of the new generation have not beencreated from the seeds that came down from thecrowns of the old trees, but from sown or plantedseeds or plants.During its lifetime the forest has to be tended.Tending of the forest implies all those cultivationprocedures by which an endeavour is made to formsuch a structure of forest as to ensure its stability,productivity, vitality, biodiversity and at the end of itslife, the capacity for high-quality naturalregeneration.Through this care we direct the development of theforest in line with the natural laws, making optimumuse of the conditions of the habitat, the biologicalconditions and ecological requirements of thespecies of trees. In this way we support and maintainthe forest in the optimum structural conditions, inwhich stability, productivity and biological diversityare the basic indicators of an optimum condition. Thepossibility of natural regeneration of forests care forin this way is the local consequence and step thatleads to their eternity. Through care both thequantity and the quality of the forest are affected(Matiæ i dr. 2003, Leibundgut 1978, Lang 1982,Koestler 1952, Pintariæ 1969).Care of forests and trees is based on the fact that thephenotype is the result of the genotype and theinfluence of the environment, that is of the conditionsof the habitat. Through care, the phenotype and thehabitat are affected. The spontaneous selection ofplants in the forest is replaced with a selection basedon silvicultural principles. Positive and negativeselection are distinguished. through negativeselection, all the undesirable individuals areperceived and removed, up to the age when thetrees of the future start being discerned. After this,one goes over to procedures of positive selection, bywhich everything is removed from the forest thathinders the development of the perceived trees ofthe future. But in so doing, one must be careful that




35

Prorjeðivanjem šume odr�ava se njezina higijena ipoma�e razvoj najboljih stabala. Oblikuju se krošnje,njeguju se debla stabala koja ostaju u šumi. Uprašumi se takoðer dogaða odabiranje stabala.Meðutim, prašuma ima svoja naèela odabira pokojima pobjeðuju biološki i ekološki jaèe vrste. Hrastlu�njak po svojim je bioekološkim osobinamanajslabija vrsta meðu drveæem nizinskih šuma(»osjetljivi kralj šume«). Zato, kada ne bi bilo struènenjege i pomlaðivanja, ne bi bilo glasovitih slavonskihhrastika veæ grabika, vrbika, jošika ili bi hrastici bilinekvalitetni, skloni sušenju i bolestima.

Slika 4. Shema razvoja šume hrasta lu�njaka, snaznakom vrste uzgojnih postupaka te krivuljamabroja stabala i obujma šume. U razdoblju od 140godina, kol iko najmanje iznosi ophodnjagospodarske hrastove šume s grabom u nas, brojstabala hrasta lu�njaka se smanji od pribli�no 50 000kom/ha, koliko ih ima u ranoj mladosti, do pribli�no100 kom/ha, koliko ih ima u 140. godini. Tih 100stabala imaju zavidne dimenzije i ljepotu, na njima jekumulirano preko 600 m /ha najkvalitetnije, glasoviteslavonske hrastovine.Ako uzmemo da je �ivotni vijek šume hrasta lu�njakaodreðen s najmanje 140 godina, jasno je da supotrebna 3 - 4 naraštaja šumarskih struènjaka kako bise podigla jedna slavonska hrastova šuma. Danasšumarstvo Hrvatske gospodari s prvom, drugom,

3

the stand does not lose the essential features: thenatural structure, the cohesion, productivity,stability, diversity and ability to regenerate naturally(Matic et al, 2003).Through the thinning of a forest, its hygiene ismaintained, and the development of the best trees ishelped. The crowns are formed, the trunks of thetrees that remain in the forest are cared for. In thevirgin forest, the selection of trees also occurs. Butthe virgin forest has its own principles of selection, inwhich the biologically and ecologically strongerspecies win. In bioecological features, the commonoak is the weakest species among the trees of thelowland forests (the vulnerable king of the forest).Thus, if there were no expert care and regeneration,there would be none of the famed Slavonian oakforests, rather stands of hornbeam, willow, alder,and the oak groves would be of low quality, apt tosickness and withering.

Figure 4. Diagram of the development of a commonoak forest, with an indication of the kinds ofcultivation procedure and the curves of numbers oftrees and volume of the forest. In a period of 140years, which is the shortest period which a cohort ofoak and hornbeam forest in this country lasts, thenumber of trees of common oak is reduced fromapproximately 50,000 to an acre, as there are inearly youth, to about 100 a hectare, which there arein the 140th year. These 100 trees haveremarkable dimensions and beauty, and they haveaccumulated over 600 cubic metres per hectare ofthe finest celebrated Slavonian oak wood.

POMLADAK MLADIK MLADA SREDNJODOBNASTARAPONIK

STARIJA STARA STARAPONIK

N-broj stabalaV-volumen

ophodnja

NV

RADOVI S TLOMZAŠTITA MLADE SASTOJINENJEGA NAKON DOVRŠNOG SJEKAPOPUNJAVANJEÈIŠÆENJE

PRORJEDE

POMLAÐIVANJE





ponegdje s treæom generacijom nizinskih hrastovihšuma. Prve je hrastike, prašume hrasta lu�njaka,poèeo pomlaðivati Josip Kozarac, nekadašnjiupravitelj šumarije Lipovljani. Danas šumaripomlaðuju one hrastike koje je on osnovao (drugageneracija).Svojedobno je Kozarac (1896.) poruèio kolegama izNjemaèke: »

. Ova je reèenica aktualna i danas kada mnogipraktièari i znanstvenici šumarstva dolaze naekskurzije u hrvatske hrastove šume vidjetigospodarenje po naèelima Zagrebaèke školeuzgajanja šuma.Zato šumarstvu u Hrvatskoj ne treba postavljatipitanja koja Bengtsson i dr. (2000.) postavljajueuropskome šumarstvu: Kako promijeniti preèestorabljenu praksu uzgajanja šumskih monokultura?Kako procese u prirodnim šumama primijeniti napraksu gospodarenja šumama? Kako razvijatipotrajno gospodarenje u gospodarskom iopæekorisnom smislu? Kako poveæati biološkuraznolikost i stabilnost šume? Ono odgovore na tapitanja ima.

Šume Hrvatske, poglavito nizinske i gorske,najznaèajnija su ekološka uporišta naše zemlje. Tomislimo danas, ali treba imati na umu da su njihovevrijednosti bili svjesni i u 18. stoljeæu. Nije zatosluèajno šumarstvo u Hrvatskoj nastalo upravo na timpodruèjima. Ono se pojavilo iz straha od nestankašuma i potrebe za oèuvanjem šuma, a razvijalo seprema naèelima Zagrebaèke škole uzgajanja šuma.Šumarstvo je tako bilo prva »ekološka«, »zelena«struka koja je uspjela odr�ati šume u stanju u kakvomsu danas.Gospodarenje šumama razvijalo se po naèeluvišenamjenske progresivne potrajnosti: uvijek naistoj površini šuma se iskorištavala koliko se mogla, aostajala je sve bolja.Zahvaljujuæi pristupu gospodarenju i zakonskimrješenjima, hrvatske su šume do danas zadr�aleprirodni karakter, a površina im je ostala saèuvana.Hrvatsko se šumarstvo mo�e pohvaliti èinjenicomkako vjerojatno jedino u Europi gospodari prirodnimšumama u skladu s prirodnim naèelima. Shvaæa linaše društvo tu prednost?

Napokon i to: nemojte gospodonjemaèki šumari hodoèastiti jedino u Spessart, nije toprava Mekka plemenite Quercus pedunculate; negoizvolite zaviriti i u Slavoniju, pa ja kriv, ako mnogi odvas æe prestati odgajati hrast ondje, gdje mu mjestanema«

ZAKLJUÈAK

If we take the average life span of a common oakforest as being at least 140 years, it is clear that aleast 3-4 generations of forestry experts are requiredto bring one Slavonian oak forest to maturity. Todaythe forestry of Croatia manages the first, second andoccasionally the third generation of lowland oakforests. The regeneration of the first oak groves, thevirgin forests of common oak, was started by JosipKozarac, the one-time warden of the forest area ofLipovljani. Today foresters are regenerating thoseoak groves that he established (2nd generation).Once, Kozarac (in 1896) told his Germancolleagues: “

”. This sentence istopical today, too, when many practical and scientificforesters go on excursions into the Croatian oakforests to see forest management according to theprinciples of the Zagreb Silviculture School.Thus forestry in Croatia need not be posed thequestion that Bengtsson et al (2000) put to Europeanforestry: How to change the too frequently usedpractice of raising forest monocultures: How to applythe processes in the natural forest to the practice offorest management? How is one to developsustainable management in an economic andgeneral-use sense? How can the biological diversityand stability of the forest be increased? For it has theanswers to all these questions.

The forests of Croatia, particularly those in thelowlands and the highlands, are the most importantecological resource of our country. We share thisopinion today, but one should bear in mind thatpeople in the 18th century were also aware of theirvalue. It is not accidental that forestry in Croatiacame into being in these very areas. It appeared outof fear of the disappearance of the forest, and theneed to preserve them, and it developed accordingto the principles of the Zagreb Silviculture School.Forestry was the first ecological and greenprofession, and managed to maintain the forests inthe condition in which we see them today.Forest management developed on the principle ofmulti-use progressive sustainability; always, on thesame area, the forest was used as much as it couldbe, and was left always in a better condition.Thanks to the approach to management and to thelegislative approaches, Croatian forests haveretained to this very day their natural character, andtheir area has remained the same. Croatian forestrycan boast of being probably the only such institutionin European terms that manages natural forests inaccordance with natural principles. Is our societyaware of this advantage?

Finally, this: don't, you Germanforesters, make pilgrimages just to Spessart, that isnot the true Meca of the noble Quercus pedunculate;but go and take a look at Slavonia, and I shall be toblame, but many of you shall cease to cultivate theoak where it has no place to be

CONCLUSION




37

LITERATURA

Bengtsson, J., S. G. Nilsson, A. Franc, P. Menozzi, 2000: Biodiversity, disturbances, ecosystem function andmanagement of European forests. Forest Ecology and Management 132(1): 39 50.

Glavaè, V., 1999: Uvod u globalnu ekologiju. Dr�avna uprava za zaštitu prirode i okoliša, »Hrvatske šume« p. o.Zagreb, 211 str., Zagreb.

Klepac, D., 1998: Hrvatsko šumarstvo u XIX. i XX. stoljeæu. U: Sveuèilišna šumarska nastava u Hrvatskoj 1898 -1998, knjiga II., Šumarski fakultet, str. 9 - 33, Zagreb.

Klepac, D., 1997: Hrvatsko šumarstvo u drugoj polovici XIX. stoljeæa. Šumarski list CXXI (3 4): 115 126, Zagreb.

Korpel, Š., M. Saniga, 1995: Prirode blizke pestovanie lesa. TU Zvolen, 158 str., Zvolen.

Korpel, Š., 1991: Pestovanie lesa. Priroda, 465 str., Bratislava.

Korpel, Š., 1989: Pralesy Slovenska. VEDA, 322 str., Bratislava.

Kozarac, J., 1896: Njemaèki šumari i uzgoj hrastovine. Šum. list, str. 144 - 152, Zagreb.

Köstler, J. N., 1953: Waldpflege. Hamburg/Berlin.

Lang, E., 1982: Pflege von Buchenbästanden im Hessichen Forstamt Happenheim.Allgemeine Forstzeitschrift,21, Muenchen.

Lebundgut, H., 1978: Die Waldpflege. Verlag Haupt, 204 str., Bern/Stuttgart.

Leibundgut, H., 1978a: Über die Dynamik europaeisher Urwaelder.Allg. Forstzeitschr. 24: 686 - 690.

Leibundgut, H., 1959: Über Zweck und Methodik der Struktur- und Zuwachsanalyse von Urwaeldern. Schwiz. Z.Forstwes.

Matiæ, S., I. Aniæ, M. Oršaniæ, 2003: Uzgojni postupci u bukovim šumama. Obièna bukva (Fagus sylvatica L.) uHrvatskoj,Akademija šumarskih znanosti, 340 - 369, Zagreb.

Matiæ, S., I. Aniæ, M. Oršaniæ, 2001: Uzgojni postupci u prebornim šumama. Obièna jela (Abies alba Mill.) uHrvatskoj,Akademija šumarskih znanosti, 407 - 443, Zagreb.

Matiæ, S., 1996: Uzgojni radovi na obnovi šuma hrasta lu�njaka. Hrast lu�njak (Quercus robur L.) u Hrvatskoj,Hrvatska akademija znanosti u umjetnosti i „Hrvatske šume“ p. o. Zagreb, str. 169 - 184, Zagreb.

Matiæ, S., B. Prpiæ, Ð. Rauš, A. Vrankoviæ, Z. Seletkoviæ, 1979: Ekološko-uzgojne osobine specijalnih rezervatašumske vegetacije Prašnik i Muški bunar u Slavoniji. U: Ð. Rauš (ur.), Drugi kongres ekologa Jugoslavije,Savez društava ekologa Jugoslavije, str. 767 - 823, 1979, Zagreb.

Meštroviæ, Š., 1995: Dvjestodvadeseta godišnjica Zakonske uredbe o šumama. Šumarski list CXIX(4): 144 -158, Zagreb.

Otto, J. H., 1998: Practical criteria and indicators of sustainability in forests. In: 2nd International Pro SilvaCongress proceedings, Pro SilvaAssociation, str. 223 - 239,Apeldoorn.

Pintariæ, K., 1969: Njega šuma. Univerzitet u Sarajevu, 187 str., Sarajevo.

Prpiæ, B., Z. Seletkoviæ, 1996: Istra�ivanja u hrvatskim prašumama i korištenje rezultata u postupku s prirodnomšumom. U: B. Mayer (ur.), Unapreðenje proizvodnje biomase šumskih ekosustava, Šumarski fakultetSveuèilišta u Zagrebu i Šumarski institut, Jastrebarsko, str. 97 - 14, Zagreb.

Vukeliæ, J., Ð. Rauš, 2001: Lowland forests in Croatia. Floodplain forests in Europe, European Forest InstituteResearch Report 10, 101 125, Leiden Boston Koeln.

Doc. dr. sc. Igor AniæSveuèilište u Zagrebu

Šumarski fakultetZavod za Uzgajanje šuma

Svetošimanska 25, 10000 Zagreb



STANJE I PROJEKCIJEBUDUÆEGA GOSPODARENJA IRAZVOJA DOBNE STRUKTURE UŠUMAMA HRASTA LU�NJAKA IPOLJSKOG JASENA NAPODRUÈJU PARKA PRIRODELONJSKO POLJE

SA�ETAK

Kljuène rijeèi:

Potencijali staništa šuma hrasta lu�njaka i poljskogjasena u nizinskim šumama Hrvatske posebno suveliki, pa su dugoroène projekcije i planiranjegospodarenja tim šumama, kako na razini cijelogpodruèja, tako i na razini manjih podruèja, osobitova�ni. Predmet ovoga rada su sastojine u ureðajnimrazredima hrasta lu�njaka (16 865 ha) i poljskogjasena (10 403 ha) na podruèju parka prirode Lonjskopolje. Cilj rada je dobiti i raspraviti projekcijebuduæega gospodarenja i razvoja dobne strukture tihšumskih resursa. Metoda simulacije zasniva se nasustav-dinamièkom modelu regularne šume.Intenzitet obnove sastojina uzima se kao najva�nijiutjecajni èimbenik buduæega razvoja dobnestrukture. Tri scenarija gospodarenja su definirana, sobzirom na naèin planiranja godišnjega površinskogetata glavnoga prihoda (na temelju ukupne površinešume, na temelju površine sastojina starijih od polaophodnje i na temelju površine sastojina zadnjegdobnog razreda). Osim toga, za ureðajni razredhrasta lu�njaka simulirano je produ�enje ophodnjena 160 godina, a za poljski jasen skraæivanjeophodnje na 80 godina. Za svaki scenarij dobivenesu projekcije godišnjega površinskog etata obnove,razvoja dobne strukture, kretanja drvne zalihe tegodišnjih etata glavnog i prethodnog prihoda. Sobzirom na poèetnu dobnu strukturu, s velikimudjelom zrelih sastojina i mladih sastojina prvogdobnog razreda u oba ureðajna razreda, razmotrenje najprihvatljiviji scenarij. Dosljedno gospodarenjedefinirano planiranjem godišnje obnove sastojina natemelju površine sastojina starijih od pola ophodnjemoglo bi voditi postizanju prihvatljivije dobnestrukture (veæ za 50 godina) kao i strukture i odnosasjeèa glavnoga i prethodnoga prihoda. Za ureðajnirazred hrasta lu�njaka planiranje bi se moglozasnivati na ophodnji od 160 godina, a za ureðajnirazred poljskog jasena na ophodnji od 80 godina.

regularno gospodarenje, razvojdobne strukture, planiranje obnove sastojina,oplodna sjeèa, ophodnja.

THE PRESENT CONDITION ANDA PROJECTION OF THE FUTUREMANAGEMENT ANDDEVELOPMENT/AGESTRUCTURE IN COMMON OAKAND NARROW-LEAVED ASHFORESTS IN THE AREA OFLONJSKO POLJE NATURE PARK

ABSTRACT

Key words:

The potentials of the common oak and narrow-leaved ash forest habitats in the lowland forests ofCroatia are particularly significant, and so the long-term projections and planning of the management ofthese forests, at the level of both the entire area andsmall areas, are of great importance. This paperconcerns stands within management classes ofcommon oak (16865 ha) and narrow-leaved ash(10403 ha) in the area of Lonjsko Polje Nature Park.The objective of the paper is to obtain and discussprojections for the future management anddevelopment of the age structure of these forestresources. The simulation method is based on thesystem/dynamic model of an even-aged forest. Theregeneration intensity of stands is taken as the mostimportant causal factor of future development of theage structure. Three scenarios for managementare defined with respect to manner of planning,annual area of the main cut (according to the totalarea of the forest, according to the area of the area ofstands older than half the rotation, and according tothe area of stands of the last age class). Apart fromthat, for the management class of common oak, theprolongation of the rotation to 160 years is simulated,and for narrow-leaved ash an abbreviation of therotation to 80 years. For each of the scenarios,projections of the annual felling cut, the developmentof the age structure, trends in timber reserves, andannual preliminary and main cuts are obtained. Themost acceptable scenario is considered with respectto the initial age structure, with a large proportion ofmature stands and young stands of the first ageclass within both management classes. Consistentmanagement defined by the planning of an annualregeneration of stands according to the area of thestands older than half a rotation could lead toattainment of acceptable age structures (in as earlyas 50 years), and to structures and relations ofintermediate and main cuts. For the managementclass of common oak, planning could be based on arotation of 160 years, and for the management classof narrow-leaved ash, on a rotation of 80 years.

regular management, development ofage structure, stand regeneration planning, seeingcut, rotation





Uvod

Predmet rada

U nizinskom podruèju Hrvatske, sa 31% obraslepovršine, vrijedne su šume hrasta lu�njaka i šumepoljskog jasena. Potencijali staništa šuma hrastalu�njaka, od 202 150 ha, i poljskog jasena, od 27 300ha, veæi su u odnosu na postojeæu strukturu drvnezalihe i volumnog prirasta (Èavloviæ, 1999.). Zbogvelikog su opæega i gospodarskoga znaèenjadugoroène projekcije i planiranje gospodarenjanizinskim šumama, kako na razini cijelog podruèja,tako i na razini manjih podruèja, osobito va�ni.U uvjetima kada postoje stalne promjene ekološkihuvjeta, razvoja i prirasta šumskih sastojina,istovremeno sa stalnim promjenama zahtjevadruštva za proizvodima i uslugama šuma, priplaniranju gospodarenja šumama treba stalnousklaðivati ponudu i potra�nju za dobrima šume. Tomo�e biti osigurano sveobuhvatnim modelimaplaniranja na razini šumske uprave, podruèja ili cijelezemlje (Mohren, 2003.).Simulacijski modeli imaju znaèajnu ulogu uprocesima odluèivanja pri planiranju i gospodarenjušumama. Brojni simulacijski modeli na razinisastojine (Pretzsch, 1997; Pretzsch et al, 2002.;Lindner et al, 1997.; Robinson and Monserud,2003.), kao i istra�ivanja utjecaja promjena stanišnihuvjeta na rast sastojina (Spiecker et al, 1996.;Karjalainen et al, 2002.; Kramer and Mohren, 2001.)predstavljeni su znanstvenoj javnosti.Na razini regularne šume (ureðajni razred, šumarija,Uprava šuma) tijekom dugog razdoblja, promjene urastu, prirastu i vrijednosti šume su uvjetovanepromjenom dobne strukture šume (Èavloviæ, 1999;Èavloviæ et al., 2000.). U kontekstu modeliranja narazini veæeg prostora (Nabuurs et al, 1998) idugoroènog planiranja (Nabuurs et al, 2001;Nabuurs et al, 2002; Nelson, 2003) u radu æe bitiprikazane projekcije buduæega gospodarenja irazvoja dobne strukture šuma hrasta lu�njaka ipoljskog jasena na razini parka prirode Lonjsko polje.Planiranje gospodarenja šumama ima nedjeljivuvremensko-prostornu dimenziju. U radu æe te�ište bitiviše na vremenskom dugoroènom planiranju, uzrazmatranje i prostorne dimenzije planiranja. Glavnicilj je utvrditi uz kakvo gospodarenje æe se dobitinajprihvatljiviji razvoj dobne strukture, kretanjestrukture obnove, drvne zalihe i sjeèa glavnog iprethodnog prihoda.

Predmet rada su sastojine ureðajnih razreda hrastalu�njaka i poljskog jasena koji se nalaze u sastavu 11gospodarskih jedinica. Gospodarske jedinice

Introduction

The subject of the paper

In the lowland area of Croatia, 31% covered withtimber, there are valuable forests of common oakand of narrow-leaved ash. The potentials of thecommon oak forest habitats, of 202,150 ha, and ofnarrow-leaved ash, of 27,300, are greater than theactual existing structure of timber reserves andvolume yield (Èavloviæ, 1999). Because of the greatgeneral and economic importance, the long-termprojections for and planning of the management ofthe lowland forests, at the level of the area as awhole, and at the level of small areas, are ofparticular importance.In conditions in which there are constant changes inthe ecological conditions, the development and yieldof forest stands, simultaneously with constantchanges in the requirements of the society for theproducts and services of the forests, forestmanagement planning needs all the time to adjustsupply of and demand for the assets of the forest.This can be secured by comprehensive planningmodels at the level of forest unit or compartment.(Mohren, 2003).Simulation models play an important role indecision-making in planning and managing theforests. Many simulation models at the level of stand(Pretzsch, 1997; Pretzsch et al, 2002; Lindner et al,1997; Robinson and Monserud, 2003), as well asresearch into the influence of habitat conditions onthe growth of stands (Speicker et al, 1996;Karjalainen et al, 2002; Kramer and Mohren, 2002),have been submitted to the scientific public.At the level of even-aged forest (management class,forest unit, forest district) over a long period of time,changes in growth, yield and value of the forest areconditioned by changes in the age structure of theforest (Èavloviæ,1999; Èavloviæ et al, 2000). In thecontext of modelling over a large area (Nabuurs et al,1998) and long-term planning (Nabuurs et al, 2001;Nabuurs et al, 2002; Nelson, 2003), the paper willshow projections of the future management anddevelopment of the age structure of forests ofcommon oak and narrow-leaved ash at the level ofLonjsko Polje Nature Park. The planning of forestmanagement constitutes a single indivisibledimension of time and space. The emphasis in thework will be on temporal long-term planning, with aconsideration of the spatial dimension of planning aswell. The main goal is to determine what kind ofmanagement will lead to the most acceptabledevelopment of the age structure, the trend inregeneration structure, timber reserves and first andfelling cuts.

The subject of the paper is stands of managementclasses of common oak and narrow-leaved ash thatare in 11 management units. The management units


39



�abarski bok, Trst ika I , Grede-Kamare,Meðustrugovi, Lonja, Brezovica, Kutinske nizinskešume, Popovaèke nizinske šume, Zelenika, JosipKozarac i Krapje ðol se u potpunosti ili najveæimdijelom nalaze na podruèju Parka prirode Lonjskopolje. Za potrebe ovoga rada nisu utvrðivani dijelovigospodarske jedinice (odsjeci) koji se ne nalazeunutar granica Parka prirode, pa se podaci ureðajnihrazreda hrasta lu�njaka i poljskog jasena ne moguuzeti kao potpuno toèni. Isto tako, dobna strukturaureðajnih razreda na razini podruèja svih 11gospodarskih jedinica nije utvrðena na temeljutrenutaène starosti svake pojedine sastojine, negona temelju postojeæe dobne strukture unutar svakepojedine gospodarske jedinice. Dobna strukturaunutar pojedine gospodarske jedinice se odnosi nagodinu obnove ili revizije osnove gospodarenja.Kako unutar navedenih 11 gospodarskih jedinicapostoji normalna dinamika ureðivanja šuma, mo�ese reæi da se dobivena dobna struktura prosjeènoodnosi na stanje prije pet godina.Dobna struktura ureðajnih razreda hrasta lu�njaka ipoljskog jasena po površini i drvnoj zalihi, te odnosprema normalnoj dobnoj strukturi prikazan je slikom 1i slikom 2. Podaci prikazani slikama pokazujupoèetno stanje projekcije buduæeg razvoja dobnestrukture.

Odnos dobne strukture po površini i drvnojzalihi za ureðajni razred hrasta lu�njaka uistra�ivanom podruèju

Slika 1.

of Zabarski bok, Trstika I, Grede-Kamare,Meðustrugovi, Lonja, Brezovica, Kutinske nizinskešume, Popovaèke nizinske šume, Zelenika, JosipKozarac and Krapje-Ðol are totally or mostly in thearea of Lonjsko Polje Nature Park. For the purposesof this work, the parts of a management unit(compartments) that are not within the borders of theNature Park are not determined, and the data of themanagement classes of oak and ash cannot beconsidered totally accurate. Similarly, the agestructure of the management classes at the level ofthe areas of all the 11 management units has notbeen determined pursuant to the current age ofevery individual stand, but on the basis of theexisting age structure within each individualmanagement unit. The age structure within anindividual management unit relates to year orregeneration or review of the management plan.Since inside these 11 management units there is anormal dynamics of forest management, it can besaid that the age structure obtained refers onaverage to the situation of five years back.The age structure of the management classes ofcommon oak and narrow-leaved ash, according toarea and timber reserves, and the ratio towards thenormal age structure, in shown in Figures 1 and 2.The data shown in the figures are the initial state ofthe projection of the future development of the agestructure.

Ratio of age structure in terms of area andtimber reserves for the management class ofcommon oak inside the research area.

Figure 1.





Slika 2. Odnos dobne strukture po površini i drvnojzalihi za ureðajni razred poljskog jasena uistra�ivanom podruèju

Figure 2. The ratio of age structure per area andtimber reserves for the management class ofnarrow-leaved ash inside the research area

Metoda projekcije buduæeg razvoja dobnestrukture

Metoda se zasniva na sustav-dinamièkom modeluregularne šume (Èavloviæ, 1996.). Slika 3. pokazujesustav regularne šume koji se sastoji od sedamdobnih razreda, s obzirom na 140-godišnju ophodnjui širinu dobnih razreda od 20 godina. To je zatvorenisustav unutar kojega se tijekom vremena odvijaprela�enje sastojina izmeðu dobnih razreda.Prela�enje sastojina (površine) u sljedeæi dobnirazred ovisi o površini dobnog razreda i širini dobnograzreda. Prela�enje sastojina iz zadnjeg u prvi dobnirazred uvjetovano je s površinom obnove sastojina(planiranje gospodarenja), pa se na taj naèin mo�eutjecati na buduæe kretanje dobne strukture. Buduæekretanje kolièine i strukture drvne zalihe, prirasta isjeèa u neposrednoj je vezi s kretanjem dobnestrukture po površini.U modelu je pretpostavljeno linearno postizanjenormalnoga prosjeènog volumena po ha (normalniobrast sastojina) prema PPT (Špiranec, 1975.) zapojedini dobni razred u definiranom vremenu.

Method of projection of future development ofthe age structure

This method is based on the system-dynamic modelof even-aged forest (Èavloviæ, 1996). Figure 2shows the system of an even-aged forest thatconsists of 7 age classes, with reference to the 140year rotation and the breadth of age classes of 20years. This is a closed system within which over timethe transition of stands between the age classestakes place. The transition of stands (areas) into thenext age class depends on the area of the age classand the width of the age class. The transition of thestands from the last to the first age class isconditioned by the area of regeneration of stands(planned management) and in this way can affect thefuture trends in the age structure. The future trend inthe volume and structure of timber reserves, yieldand harvest is in direct relation with the trend in theage structure according to area.The model assumes a linear achievement of thenormal average volume per hectare (normal cover ofstands) according to PPT (Spiranec, 1975) for agiven age class inside the defined time.


41



Dobna struktura po površini

0

500

1000

1500

2000

2500

3000

3500

I II III IV V20-god dobni razredi

pov

ršin

a(h

a)

Stvarna

Normalna10403 ha10403 ha

Dobna struktura po površini

0

500

1000

1500

2000

2500

3000

3500

I II III IV V

20-god dobni razredi

pov

ršin

a(h

a)

Stvarna

Normalna

10403 ha

Dobna struktura po drv zalihi

0

0,2

0,4

0,6

0,8

1

1,2

1,4

I II III IV V

drv

na

zali

ha

(mil

.m3)

Vk

Vkn

Vn

2.222.22 milmil. m. m33

2.642.64 milmil. m. m33

2.762.76 milmil. m. m33

Dobna struktura po drv zalihi

0

0,2

0,4

0,6

0,8

1

1,2

1,4

I II III IV V

drv

na

zali

ha

(mil

.m3)

Vk

Vkn

Vn

2.22 mil. m3

2.64 mil. m3

2.76 mil. m3

Slika 3. Sustav-dinamièki model regularne šumehrasta lu�njaka uz ophodnju od 140 godina

Figure 3. The system-dynamic model of normalforest of common oak with a rotation of 140 years.

Kao što je veæ reèeno, regularno gospodarenje jezasnovano na 140-godišnjoj ophodnji i 10-godišnjemrazdoblju oplodne sjeèe. Kako intenzitet obnove popovršini najviše utjeèe na buduæe kretanje dobnestrukture, za projekciju buduæega gospodarenjaprimijenjena su tri scenarija definirana sljedeæimjednad�bama:

Scenarij 1:

Scenarij 2:

Scenarij 3:

gdje je IO intenzitet obnove (ha/godišnje); F-ukupnapovršina šume; u-ophodnja; FM-površina sastojinastarijih od pola ophodnje i Fz-površina zadnjegdobnog razreda.

As was stated earlier, regular management is basedon a 140 year rotation and a 10 year period ofseeding cuts. Since the intensity of regeneration perarea is the most important factor impacting the futuretrends in the age structure, for the projection of futuremanagement, three scenarios are taken, defined bythe following equations:

Scenario 1:

Scenario 2:

Scenario 3:

where IO is intensity of regeneration (ha/annual); F-total area of forest; u-rotation; FM area of standsolder than half a rotation and Fz the area of the lastage class.





Rezultati projekcije razvoja dobne strukture

Tablica 1.

Temeljem izvršenoga simuliranja dobivene suprojekcije kretanja godišnjega površinskog etataglavnog prihoda (intenziteta obnove), razvoj dobnestrukture, kretanje drvne zalihe, kao i godišnjeg etataglavnoga i prethodnoga prihoda za svaki odprethodno definirana tri scenarija.Za ureðajni razred hrasta lu�njaka pri gospodarenjuuz ophodnju od 140 godina slika 4 prikazuje buduæekretanje godišnjeg površinskog etata glavnogprihoda i razvoja dobne strukture.

Radi utvrðivanja utjecaja produ�ivanja ophodnje prigospodarenju sastojinama hrasta lu�njaka nabuduæe gospodarenje, izvršeno je simuliranjegospodarenja uz ophodnju od 160 godina (slika 5).Kako se vidi iz slika 4 i 5, najveæe promjene se moguoèekivati tijekom prvoga 50-godišnjeg razdoblja. Utablici 1 su prikazani sumarni rezultati oèekivaneobnove sastojina, etata glavnog i prethodnog prihodaza prvo 50-godišnje razdoblje unutar scenarija.

Prikaz intenziteta obnove i oèekivanogetata s obzirom na ophodnju i scenarij gospodarenjaza prvih 50 godina projekcijskog razdoblja zaureðajni razred hrasta lu�njaka.

Results of the projection of the development ofthe age structure

Table 1.

According to the simulation carried out, projectionsof the annul felling cut (intensity of regeneration), thedevelopment of the age structure, the trends intimber reserves, and the annual felling andintermediate cuts have been obtained for each of thepreviously defined scenarios.For the management class of common oak inmanagement pattern with a 140 year rotation, Figure4 shows the future trends of annual felling cut andthe development of the age structure.

For the sake of determining the impact of theextension of the rotation while managing commonoak stands on the future management, a simulationof management with a 160 year rotation was carriedout (Figure 5).

Review of intensity of regeneration andexpected permissible cut with respect to rotation andmanagement scenario for the first 50 years of theprojection period for the common oak managementclass.

As can be seen from Figures 4 and 5, the greatestchanges can be expected during the first 50 yearperiod. Table 1 shows the summary results of theexpected regeneration of the stands, the main andthe intermediate cut for the first 50 year period withinthe scenarios.


43



Isto kao za ureðajni razred hrasta lu�njaka, dobivenirezultati za ureðajni razred poljskog jasena prigospodarenju uz ophodnju od 100 godina prikazanisu slikom 6. S obzirom na zastupljenost prezrelihsastojina jasena, starijih i od 100 godina, tepropisanu ophodnju za jasen, slikom 7 je prikazanutjecaj gospodarenja uz ophodnju od 80 godina nadinamiku obnove i razvoja dobne strukture.

Najveæe promjene u kretanju dobne strukture iobnove (scenarij 3) mogu se oèekivati tijekom prvih40 godina.

Prikaz intenziteta obnove i oèekivanogetata s obzirom na ophodnju i scenarij gospodarenjaza prvih 40 godina projekcijskog razdoblja zaureðajni razred poljskog jasena.

Tablica 2.

Just as with the common oak management class,the results obtained for the narrow-leaved oakmanagement class, with a rotation of 100 years, areshown in Figure 6. Because of the representationof over-mature stands of ash, older than 100 years,and the prescribed rotation for ash, Figure 7 showsthe effect of management with an 80 year rotation onthe dynamics of regeneration and the developmentof the age structure.

The greatest changes in the trends in the agestructure and regeneration (Scenario 3) can beexpected during the first 40 years.

Review of the intensity of regeneration andthe expected permissible cut with respect to rotationand management scenario for the first 40 years ofthe projection period for the narrow-leaved ashmanagement class.

Table 2.

Zakljuèna rasprava

Modeliranje scenarija dugoroènog gospodarenjašumom na razini šireg prostora ima za cilj podr�atiprostorno i vremensko planiranje gospodarskihpostupaka (Baskent et al., 2002.; Rohner andBoswald, 2001.; Ohman and Lamas, 2003.).Meðutim, ukljuèivanje prostora kao elementaplaniranja pri dugoroènom planiranju mo�e proceseplaniranja znatno ote�ati (Ohman and Lamas,2003.). S obzirom na razinu planiranja, u ovom raduje razmotren dugoroèni utjecaj tri razlièita scenarijagospodarenja na dinamiku buduæe obnove sastojina,razvoj dobne strukture te kretanje drvne zalihe isjeèa. Prostor nije neposredno ukljuèen, meðutim onje nedjeljivi element koji se razmatra u okvirucjelovitog planiranja.Planiranje buduæega gospodarenja regularnomšumom ovisno je o postojeæoj (poèetnoj) dobnojstrukturi šume (Èavloviæ, 1996.; Salo and Tahvonen,2002.). Nepravilna dobna struktura, s velikimudjelom starih i mladih sastojina te malim udjelomsrednjodobnih sastojina za oba ureðajna razreda,

Conclusion

The modelling of scenarios for the long-timemanagement of forests at the level of a wider area isaimed at supporting the spatial and temporalplanning of management procedures (Baskent et al.,2002; Rohner and Boswald, 2001; Ohman andLamas, 2003). However, the inclusion of the area asan element of planning may, in the case of long-termplanning, make the planning process extremelycomplex (Ohman and Lamas, 2003). Considering theplanning level, this paper has considered the long-term impact of three different management scenarioson the dynamics of the future regeneration of stands,the development of the age structure, and trends intimber reserves and felling. The space is not includeddirectly, but it is nevertheless an inseparable elementthat is considered within the framework of totalplanning.The planning of the future management of an even-aged forest depends on the existing (initial) agestructure of the forest (Èavloviæ, 1996; Salo andTahvonen, 2002) An irregular age structure with alarge proportion of old and young stands, and a smallproportion of medium aged stands for both





razmotrena je kao va�an utjecajni èimbenik nabuduæe gospodarenje (Slika 1 i Slika 2).Razmatrajuæi posebno va�an ureðajni razred hrastalu�njaka (Slika 1), mo�e se na prvi pogled usporeditidobna struktura po površini i drvnoj zalihi i njezinodnos prema normalnoj. Isto tako se vidi (Slika 1b) daje obrast starih sastojina manji od normalnog.Meðutim, kada bi se dublje ulazilo u analizu strukturesastojina petog, šestog i sedmog dobnog razreda,vidjelo bi se da je stanje još nepovoljnije, s obziromna udio stabala i drvne zalihe hrasta lu�njaka. Sdruge strane, stanje i struktura sastojina znaèajnozastupljenog prvog dobnog razreda nepoznate su. Sobzirom na probleme i poteškoæe koji postojeprilikom obnove lu�njakovih sastojina i na podruèjuLonjskog polja, mo�e se pretpostaviti da je strukturaovih sastojina u prvim razvojnim stadijima daleko od�eljene. Prema tome, to su elementi koji mogu bitiogranièavajuæi èimbenici prilikom provedbeplaniranih gospodarskih postupaka o kojima trebavoditi raèuna. Uoèljiv je i pozitivan utjecaj na br�euspostavljanje normalne dobne strukture, s obziromna zakonitost - što je kraæa ophodnja, br�e jepostizanje normalne dobne strukture uz dosljednogospodarenje (Èavloviæ, 1996.).Ophodnju kao vremensku i plansku velièinu ukontekstu vremenskog planiranja treba razmotritikao posebno znaèajan utjecajni element. Na razinišume (ureðajni razred na razini gospodarskejedinice, šumarije ili šireg podruèja) ophodnjom kaostalnim planskim elementom definira se broj dobnihrazreda, dobna struktura, normalitet šume,uspostava normalne dobne strukture, obnovasastojina te etat glavnog i prethodnog prihoda.Utjecaj produljenja ophodnje na intenzitet buduæeobnove, buduæe kretanje dobne strukture i sjeèa vidise iz slika 4 i 5 i tablice 1. Produljenjem ophodnje sa140 na 160 godina za ureðajni razred hrasta lu�njakasmanjio bi se godišnji intenzitet obnove sastojina za15 do 55 ha, ovisno o scenariju, te bi se smanjiogodišnji etat glavnog prihoda, a poveæao etatmeðuprihoda, tijekom prvoga 50-godišnjegrazdoblja. Posebno je uoèljiv pozitivan utjecajprodu�enja ophodnje na kretanje dobne strukture(Slika 5c) u okviru scenarija 2, u okviru kojega jepostignuta zadovoljavajuæa dobna struktura veænakon 50 godina. Skraæivanje ophodnje sa 100 na 80godina unutar gospodarenja ureðajnim razredomjasena (Slike 6 i 7, Tablica 2) utjecalo bi na poveæanjegodišnjeg intenziteta obnove za okruglo 30 do 40 ha,poveæanje godišnjeg etata glavnog prihoda ismanjenje godišnjeg etata meðuprihoda, kao ipoveæanje ukupnih godišnjih sjeèa tijekom prvog 40-godišnjeg razdoblja.S druge strane, ovdje valja istaknuti razliku izmeðuznaèenja ophodnje na razini šume, koje je prethodno

management classes is considered an importantfactor impacting future management (Figures 1 and2). Considering the particularly importantmanagement class of common oak (Figure 1), at aglance it is possible to compare age structure interms of area and timber reserves and its relationtowards the even aged. In addition it is possible tosee (Figure 1b) that the coverage of old stands issmaller than that of the even aged stands.However, if one were to go more deeply into ananalysis of the structure of the stands of the fifty, sixthand seventh age class, it would be seen that thesituation is still less propitious, consider theproportion of common oak trees and timberreserves. On the other hand, the state and structureof stands of the first age class, very considerablyrepresented, is unknown. Because of the problemsthat exist during regeneration of common oak standsin the region of Lonjsko Polje too, it can be assumedthat the structure of these stands in the firstdevelopment stages is very far from the desirable.Accordingly, these are elements that may beconstraining factors during the implementation of theplanned management procedures, that should beborne in mind. It is clear that there is a positive effecton the faster establishment of an even-agedstructure, considering the law that the shorter therotation, the faster the achievement of an even-agedstructure assuming consistent management(Èavloviæ, 1996).Rotation, as temporal and planning dimension in thecontext of temporal planning, needs considering asa particularly important conditioning element. At thelevel of the forest (management class at the level ofthe management unit, forest unit or larger area),through rotation, a constant element of planning, thenumber of age classes is defined, the age structure,the even-agedness of the forest, the establishmentof an even age structure, regeneration of stands,and the felling and intermediate cuts. The impact ofextending the rotation on the intensity of futureregeneration, future trends in age structure and cutscan be seen from Figures 4 and 5 and Table 1. By aprolongation of the rotation from 140 to 160 years,for the management class of common oak, theannual intensity of regeneration of stands would ereduced by 15 to 55 ha, depending on the scenario,and the annual felling cut would be reduced, whilethe intermediate cut would be increased, during thefirst 50 year period. Particularly visible is the positiveeffect of the prolongation of the rotation on the trendsin the age structure (Figure 5c) within the frameworkof Scenario 2, in the context of which a satisfactoryage structure is achieved as early as within 50 years.Abbreviation of the rotation from 100 to 80 yearswithin management of the ash management class(Figures 6 and 7, table 2) would have an effect onincreasing the annual intensity of regeneration to around 30 to 40 ha, increase of the annual felling cutand reduction of the annual intermediate cut, as wellas increase of the total annual cuts of the first forty


45



opisano i na razini sastojine ili odsjeka. Na razinisastojine, ophodnja bi zapravo trebala predstavljatiprosjek sjeèivih dobi svih sastojina unutar šume, a nekrutu vremensku velièinu kojom se definira sjeèivadob svih sastojina. Fleksibilnost u odstupanjusjeèivih dobi sastojina od definirane ophodnje boljeæe uva�avati postojeæe stanje svake pojedinesastojine, rezultirat æe veæim uspjesima pri obnovisastojina i vodit æe popravljanju dobne strukturešume. To treba biti osigurano odgovarajuæomzakonskom regulativom, podzakonskim aktima,dosljednom provedbom i kontrolom gospodarskihpostupaka.S obzirom na utjecaj postojeæe dobne strukture nabuduæe gospodarenje šumom, ovdje treba razmotritii utjecaj definiranih scenarija buduæeg gospodarenja,odnosno naèina odreðivanja godišnjega površinskogetata glavnoga prihoda (obnove sastojina). Natemelju slika 4-7 i tablica 1 i 2, mo�e se opæenito reæida bi gospodarenje definirano prema scenarijima 2 i3 bolje uva�avalo postojeæu dobnu strukturu šume.Intenzivnija obnova sastojina tijekom razdoblja prvih50 godina, odnosno prvih 40 godina premascenarijima 2 i 3 vodilo bi prihvatljivijem razvojudobne strukture, kao i dinamici, kolièini i strukturibuduæih sjeèa glavnog i prethodnog prihoda. Pri tomse gospodarenje definirano scenarijem 2 posebnoizdvaja kao najprihvatljivije, s obzirom na manjeoscilatorno kretanje godišnje obnove i sjeèa te drvnezalihe u odnosu na scenarij 3. S druge strane, manjeintenzivna obnova tijekom prvog 50-godišnjegrazdoblja prema scenariju 1 dovela bi do poveæanjaprosjeène starosti sastojina i gomilanja prezreledrvne zalihe. Schelhaas et al. (2003.) napominju dapoveæanje srednje starosti sastojina i drvne zaliheèini šumu manje otpornom na štete. Meðutim, u šumis velikim udjelom zrelih sastojina, gdje i priintenzivnijoj obnovi (Scenarij 2 i 3) jedan dio zrelihsastojina treba “èekati” na red za obnovu duljevrijeme, va�no je odabrati one sastojine za obnovukod kojih postoji najveæi prioritet za obnovom odsastojina koje se mogu “konzervirati” na duljevrijeme.Opæenito se mo�e zakljuèiti da bi gospodarenjesastojinama hrasta lu�njaka definirano scenarijem 2,odnosno planiranje godišnjega površinskog etataglavnoga prihoda na temelju površine sastojinastarijih od pola ophodnje bilo najprihvatljivije kako uzophodnju od 140 tako i uz ophodnju od 160 godina.Uz pretpostavku gospodarenja uz ophodnju od 160godina, s najintenzivnijom obnovom od prosjeèno116,4 ha godišnje tijekom prvog 50-godišnjegrazdoblja, prema scenariju 2 bi se postigaonajprihvatljiviji razvoj dobne strukture, te kretanje istruktura drvne zalihe i etata. Kod ureðajnog razredapoljskog jasena nije se pokazao znaèajan utjecaj

year period.On the other hand, it is necessary to highlight herethe difference between the importance of therotation at the level of the whole forest, as previouslydescribed, and at the level of stand or compartment.At the stand level, a rotation should represent theaverage of fellable ages of all stands inside theforest, and not an inflexible temporal dimensiondefining the fellable age of all the stands. Flexibilityin deviating fellable ages of stands from the definedrotation will pay more appropriate attention to theexisting condition of each individual stand, result ingreater success in the regeneration fo the stands,and lead towards an improvement in the agestructure of the forest. This should be provided bythe relevant statutory regulation, byelawinstruments, consistent implementation and controlof economic procedures.Because of the effect of the existing age structure onfuture forest management, here it is necessary toconsider the impact of defined scenarios of futuremanagement, that is of the manner of determiningthe annual felling cut (regeneration of stands).According to Figures 4-7 and Tables 1 and 2, it canbe said in general that management definedaccording to scenarios 2 and 3 would better respectthe existing age structure of the forest. Morevigorous regeneration of the stands during theperiod of the first 50 years, or the first 40 years,according to scenarios 2 and 3, would lead towardsa more acceptable development of the agestructure, and a dynamics, volume and structure offuture felling and preliminary cuts. Managementdefined by Scenario 2 stands out as the mostacceptable, considering the smaller oscillations inthe trends of the annual felling, and timber reservesas compared with Scenario 3. On the other hand, theless vigorous regeneration during the first 50 7earperiod according to Scenario 1 would lead to anincrease in the average age of the stands and theaccumulation of over-mature timber reserves.Schelhaas et al., (2003) note that an increase in theaverage age of stands and timber reserves makes aforest less resistant to damage. However, in forestswith a large proportion of mature stands, where evenwith more vigorous regeneration (Scenarios 2 and 3)some of the mature stands have to wait in turn forregeneration for quite a long time, it is important tochoose for regeneration those stands in which thereis the greatest priority for regeneration as againstthose stands that can be put on hold for a longerperiod of time.In general it can be concluded that management ofcommon oak stands defined by Scenario 2, that is,the planning of the annual felling cut according to thearea of stands older than half the rotation, would bethe most acceptable, both with a rotation of 140 andwith one of 160 years. Assuming management witha rotation of 160 years, with a most vigorousregeneration of an average of 116.4 ha annuallyduring the first 50 year period, Scenario 2 would give





razlièitih scenarija i skraæivanja ophodnje na buduæekretanje dobne strukture. Uz dosl jednogospodarenje, veæ nakon 40 godina postigla bi sezadovoljavajuæa ravnote�a u dobnoj strukturi ikretanju i strukturi drvne zalihe i etata. Uzpretpostavku gospodarenja uz ophodnju od 80godina i nešto ipak prihvatljivijega gospodarenjaprema scenariju 2, godišnji intenzitet obnove tijekomprvog 40-godišnjeg razdoblja bi se poveæao za oko30 ha, poveæao bi se etat glavnoga prihoda isveukupni etat u odnosu na 100-godišnju ophodnju.Sve projekcije buduæega gospodarenja prikazane urezultatima zasnivaju se na optimistiènimpretpostavkama, ponajprije uspješne obnovesastojina na vremenski planiranim površinama, kao ipostupnog postizanja normalnog obrasta i strukturesastojina. To znaèi da planiranu obnovu sastojinaureðajnog razreda hrasta lu�njaka (116 ha godišnje)treba u prvom 10-godišnjem gospodarskompolurazdoblju zapoèeti i uspješno ostvariti na 1160 hau onim sastojinama ili dijelovima postojeæih sastojinagdje su zahtjevi za obnovom najpreèi. S obzirom naprostornu dimenziju planiranja, nu�no je utvrditioptimalnu prosjeènu površinu sastojina koje seobnavljaju, kao i njihov razmještaj u prostoru.Smanjivanje prosjeène površina (sastojine) koja seobnavlja sa 20 ha na 10 ha ili manje znaèilo biintenzivnije gospodarenje i ureðivanje šuma, tekratkoroèno veæa ulaganja u šumu. S druge strane,postoji pretpostavka da bi to bila dobra podloga zauspješniju i kvalitetniju obnovu i njegu sastojina, štobi se na opæoj i dugoroènoj razini isplatilo. Bezkvalitetnih sastojina u prvom dobnom razredu i bezkvalitetne obnove sastojina ne mo�e se zasnivatioèekivana i �eljena buduænost regularne šume.

the most acceptable development of the agestructure, and trend and structure of timber reservesand felling. In the case of the management class ofnarrow-leaved ash, no significant impact of thedifferent scenarios and the reduction of the rotationon the future trends in the age structure was shown.In conjunction with consistent management, as soonas after 40 years, a satisfactory equilibrium in theage structure, and in the trends and structure of thetimber reserves and the permissible cut would beachieved. Assuming management with a rotation of80 years and the (after all) slightly more acceptablemanagement pattern of Scenario 2, the annualintensity of regeneration during the first 40-yearperiod would be increased by about 30 ha, the fellingcut and the overall permissible would be achieved asagainst a 100 year rotation.All projections of future management shown in theresults are based on optimistic assumptions, aboveall of successful regeneration of stands on thetemporally planned areas, and the gradualattainment of even aged cover and structure ofstands. This means that the planned regeneration ofstands of the management class of common oak(115 ha a year) in the first 10 year management half-period should be started and successfully carried outon 1160 ha in those stands or parts of existing standswhere there is the highest priority requirement forregeneration. Considering the spatial dimension ofplanning, it is necessary to lay down the optimumannual area of stands to be regenerated, as well astheir geographical distribution. Reduction of theaverage area (of the stand) to be regenerated from20 ha to 10 ha or less would mean more vigorousmanagement of the forests, and a short-term largeinvestment in the forest. On the other hand, it can behypothesised that it would be a good base for moresuccessful and higher-quality regeneration andtending of stands, which would at the general andlong-term level pay. Without high-quality stands inthe first age class and high-quality standregeneration, it is impossible to found the expectedand desirable future of an even-aged forest.


47



Literatura

Baskent, E.Z. and Jordan, G.A., 2002. Forest landscape management modeling using simulated annealing. For.Ecol. Manage. 165(1-3), 29-45.

Èavloviæ, J., 1996. Using system dynamics in even-aged forests management in the area of the Zagreb forestdistrict. Glas. šum. pokuse. 33, 109-152. (in Croatian, with English abstract).

Èavloviæ, J., 1999. Management of floodplain and lowland forests in Croatia. Ekologia-Bratislava. 18(1), 164-176.

Èavloviæ, J., Bo�iæ, M. and Lukiæ, N., 2000. Trends in forest and timberland values in the dynamic system of aneven-aged forest of pedunculate oak in the management unit “Josip Kozarac”. Glas. šum. Pokuse. 37, 8393.

Karjalainen, T., Pussinen, Ari., Liski, J., Nabuurs, G.-J., Erhard, M., Eggers, T., Sonntag, M. and Mohren, G.M.J.,2002. An approach towards an estimate of the impact of forest management and climate change on theEuropean forest sector carbon budget: Germany as a case study. For. Ecol. Manage. 162(1), 87-103

Kramer, K. and Mohren, G.M.J., 2001. Long-term effects of climate change on carbon budgets of forests inEurope. In: Kramer, K., Mohren, G.M.J. (Eds), Wageningen University and Research Centre, Alterra-report194, 290 p.

Lindner, M., Sievänen, R. and Pretzsch, H., 1997. Improving the simulation of stand structure in a forest gapmodel, For. Ecol. Manage. 95(2), 183-195.

Mohren, G.M.J., 2003. Large-scale scenario analysis in forest ecology and forest management. Forest Policyand Economics. 5,103-110.

Nabuurs, G.J., Nuutinen, T., Bartelink, H., Korhonen, M. (Eds.), 1998. Forest scenario modelling for ecosystemmanagement at landscape level. In: Nabuurs, G.J., Nuutinen, T., Bartelink, H., Korhonen, M. (Eds.),Proceedings of the International Seminar and Summer School, 26 June3 July 1997, Wageningen, TheNetherlands, EFI Proceedings No. 19, 382 p.

Nabuurs, G.J., Päivinen, R., Schelhaas, M.J., Verkaik, E., Pussinen, A. and Mohren, G.M.J., 2001. Nature-oriented forest management in Europe: modeling the long-term effects. Journal of Forestry. 99, 2833.

Nabuurs, G.J., Päivinen, R., Pussinen, A. and Schelhaas, M.J., 2002. European forests until 2050a projection offorest resources and forest management in thirty countries. European Forest Institute Research Report No.15, Leiden, Brill, 242 p.

Nelson, J., 2003. Forest-level models and challenges for their successful application. Canadian Journal ofForest Research. 33(3), 422-429.

Ohman, K. and Lamas, T., 2003. Clustering of harvest activities in multi-objective long-term forest planning. For.Ecol. Manage. 176(1-3), 161-171.

Pretzsch, H., Biber, P. and Dursky, J., 2002. The single tree-based stand simulator SILVA: construction,application and evaluation. For. Ecol. Manage. 162, 3-21.

Pretzsch, H., 1997. Analysis and modeling of spatial stand structures. Methodological considerations based onmixed beech- larch stands in Lower Saxony. For.Ecol . Manage. 97(3) , 237-253.Robinson, A.P. and Monserud, R.A., 2003. Criteria for comparing the adaptability of forest growth models.For. Ecol. Manage. 172, 53-67.

Rohner, M. and Boswald, K., 2001. Forestry development scenarios: timber production, carbon dynamics in treebiomass and forest values in Germany. Silva. Fenn. 35(3), 277-297.

Salo, S. and Tahvonen, O., 2002. On the optimality of a normal forest with multiple land classes. Forest Science.48(3), 530-542.

Schelhaas, M.J., Nabuurs, G.J. and Schuck, A., 2003. Natural disturbances in the European forests in the 19thand 20th centuries. Global Change Biology. 9(11), 1620-1633.

Spiecker, H., Mielikäinen, K., Köhl, M., Skovsgaard, J.P. (Eds.), 1996. Growth Trends in EuropeanForestsStudies from 12 Countries. In: Spiecker, H., Mielikäinen, K., Köhl, M., Skovsgaard, J.P. (Eds.),





European Forest Research Report No. 5. Springer, Berlin, 372 p.

Spiranec, M. 1975: Growth-yield tables for oak, common beech, hornbeam and chestnut (Prirasno-prihodnetablice za hrastove, bukvu, obièni grab i pitomi kesten). Radovi Šumar. inst, Zagreb. 25, 1-103. (in Croatian)

Dr. sc. Juro ÈavloviæSveuèilište u Zagrebu

Šumarski fakultetZavod za Ureðivanje šuma

Svetošimunska 25, 10000 Zagreb


49



God. površinski etat glavnog prihoda

80

90

100

110

120

130

140

150

160

170

1 11 21 31 41 51 61 71 81 91vrijeme (god)

pov

ršin

a(h

a)

Scen. 1

Scen. 2

Scen. 3

0

500

1000

1500

2000

2500

3000

3500

4000

4500

1 11 21 31 41 51 61 71 81 91vrijeme (god.)

po

vrš

ina

(ha)

IIIIIIIVVVIVII

Scenarij 1

0

500

1000

1500

2000

2500

3000

3500

4000

4500

1 11 21 31 41 51 61 71 81 91vrijeme (god)

povr

šina

(ha)

IIIIIIIVVVIVII

Scenarij 2

0

500

1000

1500

2000

2500

3000

3500

4000

4500

1 11 21 31 41 51 61 71 81 91vrijeme (god)

pov

ršin

a(h

a)

IIIIIIIVVVIVII

Scenarij 3

0

20

40

60

80

100

120

140

160

1 11 21 31 41 51 61 71 81 91

Scen. 1

Scen. 2

Scen. 3

po

vrš

ina(

ha

)

vrijeme (god.)


0

500

1000

1500

2000

2500

3000

3500

4000

4500

1 11 21 31 41 51 61 71 81 91

povr

šina

(ha)

IIIIIIIVVVIVIIVIII

vrijeme (god.)

Scenarij 1

Slika 4.

Figure 4.

Projekcije godišnjeg površinskog etata glavnog prihoda (obnove) te razvoja dobnestrukture za ureðajni razred hrasta lu�njaka uz ophodnju od 140 godina.Projections of the annual felling cut and development of the age structure for themanagement class of common oak assuming a rotation of 140 years.

Slika 5.

Figure 5.

Projekcije godišnjega površinskog etata glavnoga prihoda (obnove) te razvoja dobne strukturza ureðajni razred hrasta lu�njaka uz ophodnju od 160 godina.

Projection of the annual felling cut and development of age structure for the common oakmanagement class assuming a rotation of 160 years.

0

500

1000

1500

2000

2500

3000

3500

4000

4500

1 11 21 31 41 51 61 71 81 91

IIIIIIIVVVIVIIVIII

povr

šina

(ha)

vrijeme (god.)

Scenarij 2

0

500

1000

1500

2000

2500

3000

3500

4000

4500

1 11 21 31 41 51 61 71 81 91

IIIIIIIVVVIVIIVIII

po

vrš

ina

(ha)

vrijeme (god.)

Scenarij 3


80

90

100

110

120

130

140

150

160

1 11 21 31 41 51 61 71 81 91vrijeme (god)

pov

ršin

a(h

a)

Scen. 1

Scen. 2

Scen. 3

Scenario 1

1200

1400

1600

1800

2000

2200

2400

2600

2800

3000

3200

1 11 21 31 41 51 61 71 81 91vrijeme (god)

pov

ršin

a(h

a)

IIIIIIIVV

Scenario 2

1200

1400

1600

1800

2000

2200

2400

2600

2800

3000

3200

1 11 21 31 41 51 61 71 81 91vrijeme (god)

pov

ršin

a(h

a)

IIIIIIIVV

Scenario 3

1200

1400

1600

1800

2000

2200

2400

2600

2800

3000

3200

1 11 21 31 41 51 61 71 81 91vrijeme (god)

pov

ršin

a(h

a)

IIIIIIIVV

Slika 6.

Figure 6.

Projekcije godišnjeg površinskog etata glavnog prihoda (obnove) te razvoja dobne struktureza ureðajni razred poljskog jasena uz ophodnju od 100 godina.

Projections of the annual felling cut and the development of the age structure forthe narrow-leaved ash management class with a rotation of 100 years.


100

120

140

160

180

200

220

240

1 11 21 31 41 51 61 71 81 91vrijeme (god)

po

vrš

ina

(ha

)

Scen. 1

Scen. 2

Scen. 3

Scenarij 1

1000

1500

2000

2500

3000

3500

4000

4500

5000

1 11 21 31 41 51 61 71 81 91vrijeme (god)

po

vrš

ina

(ha

)

I

II

III

IV

Scenarij 2

1000

1500

2000

2500

3000

3500

4000

4500

5000

1 11 21 31 41 51 61 71 81 91vrijeme (god)

pov

ršin

a(h

a)

I

II

III

IV

Scenarij 3

1000

1500

2000

2500

3000

3500

4000

4500

5000

1 11 21 31 41 51 61 71 81 91vrijeme (god)

po

vrš

ina

(ha

)

I

II

III

IV

Slika 7.

Figure 7.

Projekcije godišnjeg površinskog etata glavnog prihoda (obnove) te razvoja dobne struktureza ureðajni razred poljskog jasena uz ophodnju od 80 godina.

Projection of the annual felling cut and the development of the age structure forthe narrow-leaved ash management class assuming a rotation of 80 years.

Šumski predjel Zelenika - dobna struktura 1995. godine

Šumski predjel Zelenika - stanje dovršnog i naplodnosjeka 2004. godine

Karta 2.

Map 2.

Sadašnje stanje šuma u gospodarskoj jedinici Zelenika, šumski predjel Zelenika.Current state of the forests in the Zelenika Management Unit, forest area of Zelenika.

Karta 1.

Map 1.

Stanje dobnih razreda u gospodarskoj jedinici Zelenika, 1986. god.Condition of age classes in Zelenika Management Unit, 1986

PRIKAZ STANJA DOBNIHRAZREDA NA PODRUÈJUPARKA PRIRODE LONJSKOPOLJE

Uvod

Park prirode Lonjsko polje obuhvaæa površinu od 50650 ha (odnosno 51 094 ha, temeljem GIS-podataka, Prijedlog Prostornog plana podruèjaposebnih obilje�ja PPLP), a prostire se na podruèjuLonjskog i Mokrog polja, uz lijevu obalu rijeke Save.Taj je, s gledišta zaštite prirodne i kulturne baštine,znaèajni prostor najveæa zaštiæena moèvara uHrvatskoj, Ramsarsko moèvarno podruèje i va�nostanište ptica (Important Bird Area) te jedno odnajznaèajnijih zaštiæenih podruèja u Europi.Raspored šuma, poljoprivrednih površina,travnjaka/pašnjaka, odnosno raspored vegetacije,ovisio je o èovjekovoj aktivnosti, ali i o vrstama tala,visini podzemnih voda i trajanju plavljenja, kao i omikroklimatskim prilikama. Preko 77% površineovoga podruèja obraslo je šumom, travnjacima iostalom prirodnom vegetacijom. Opæenito se mo�ereæi da je to podruèje u vegetacijskom smislu prostorizuzetne biološke raznolikosti i zato savršenostanište velikoga broja kopnenih �ivotinjskih vrsta iptica, a njegove su vodene i moèvarne površineveoma povoljne za �ivot mnogih riba i vodozemaca.Tijekom posljednjih dvadesetak godina dogodile suse znatne promjene u naèinu iskorištavanjazemljišta: napuštena je poljoprivredna proizvodnja,pašnjaèki uzgoj stoke; na djelu je zapuštanjezemljišta uopæe. Taj je proces bio osobito izrazit uposljednjih desetak godina, što je posljedica ratnihrazaranja. Napuštene površine, osobito pašnjaèke,poèela je obrastati šumska vegetacija sa svojiminicijalnim, sukcesijskim fazama. Tako se na mnogimmjestima pojavljuju šibljaci vrba, topola, johe i jasena.Vegetacija ovoga podruèja pripada nizinskomvegetacijskom pojasu koji se prostire u visini od 80 do150 metara, buduæi da je i sav prostor Lonjskog poljaispod nadmorske visine od 150 m. On èini poèetnurazinu vertikalnog pridolaska šumske vegetacije utom podruèju i obilje�avaju ga ponajprije šume hrastalu�njaka, poljskoga jasena, crne johe, vrba i topola, anjihov je nastanak i opstanak manje-više u svezi spovršinskom i podzemnom vodom.Odluèujuæi ekološki èimbenik u nastajanju i razvojušumske vegetacije ovoga kraja je voda, bilo da je rijeèo poplavnoj, kao kod topolovih i vrbovih šuma,podzemnoj (šume hrasta lu�njaka) ili su joj prijeko

A REVIEW OF THE CONDITIONOF AGE CLASSES IN THE AREAOF LONJSKO POLJE NATUREPARK

Introduction

Lonjsko Polje Nature Park occupies an area of50,650 ha (or 51,094 ha according to GIS data,Proposal of the Physical Plan of the Lonjsko PoljeNature Park Special Characteristics Area), and islocated in the area of Lonjsko and Mokro Poljealongside the left bank of the Sava River.This area, very important from the point of view ofnature and cultural heritage conservation, is thelargest protected wetland area in Croatia, a RamsarArea and an Important Bird Area, and is all in all oneof the most important conservation areas in Europe.The distribution of forests, agricultural areas,grasslands and pasturelands, or alternatively thedistribution of vegetation, has developed inresponse to human activities, as well as to the kindsof soil, the level of the underground water, theduration of floods and the microclimatic conditions.Over 77% of the area of the area is covered withforest, grasslands and other forms of naturalvegetation. In general it can be said that this area is,from the point of view of vegetation, land ofexceptional biological diversity that consequentlyconstitutes an ideal habitat for a large number ofterrestrial animal species and birds, while theaquatic and wetland areas constitute a veryfavourable resort for a large number of fish andamphibians.During the last twenty or so years important changesin the manner of using the land relate to the neglectof agricultural production, the abandonment ofpasturing in animal husbandry and the desertion ofthe land in general. The process was particularlymarked during the last twenty years, in consequenceof devastation in the war. The land that wasabandoned, particularly pasture land, was begun tobe overgrown by forest vegetation in its initialsuccession phases. Thus in many places coppicesof willow, poplar, alder and ash have started toappear.The vegetation of the area is classified into the lowlandvegetation zone that covers altitudes between 80 and150 metres, since the whole of Lonjsko Polje isactually below an altitude of 150 m. It represents theinitial level of the vertical appearance of forestvegetation in the area, characterised primarily byforests of common oak, narrow-leaved ash, blackalder, willow and poplar, while the occurrence andpersistence of it is more or less related to the surfaceand underground water.The crucial ecological factor in the origin and





potrebne i jedna i druga voda, kao što je to sašumama u kojima prevladavaju vrste crna joha ipoljski jasen.

Ukupna površina šuma i šumskog zemljišta napodruèju Parka prirode Lonjsko polje iznosi 30987,90 hektara (temeljem GIS podataka, PrijedlogProstornog plana podruèja posebnih obilje�jaPPLP).

Normalna je ona šuma koja ima drvnu masu nu�nu idovoljnu da proizvede svake godine najpovoljnijiprihod, s obzirom na postojeæe stanište, vrstu drveæai oblik gospodarenja (D. Klepac, Ureðivanje šuma,Zagreb 1965.). U visokim je regularnim šumamanormalitet po površini definiran jednim potpunimnizom dobnih razreda jednake produktivne površine inormalnog obrasta.

Stanje dobnih razreda po površini napodruèju Parka prirode i okolice

Stanje šuma prema rasporedu dobnih razreda napodruèju PP Lonjsko polje

Grafikon 1.

development of forest vegetation in this region iswater, whether it is floodwater, as is the case with thepoplar and willow woods, or of underground water (thecommon oak forests), or whether both kinds of waterare essential, as is the case in the forests in which theblack alder and narrow-leaved ash are dominant.The total area of forest and forest land in the area ofLonjsko Polje Nature Park comes to 20, 987.90hectares (according to GIS data, Proposal of thePhysical Plan of Special Features Areas of LonjskoPolje Nature Park).

The concept normal forest implies a forest that hasthe timber mass that is necessary and sufficient toproduce the most favourable yield each year withrespect to the existing habitat, kind of trees andforms of management (D. Klepac, [ForestManagement], Zagreb 1965). In high even-agedforests normality per unit of area is defined by a fullsequence of age classes of equal productive areaand normal cover.

Condition of age classes per unit of area inthe area of the Nature Park and surrounds

The state of the forests according to thedistribution of age classes in the area of LonjskoPolje Nature Park

Graph 1.

Podaci iz grafièkog prikaza (grafikon 1.) pokazujuraspored dobnih razreda gospodarskih šuma popovršini u Parku prirode Lonjsko polje i okolici. Urazmatranje nisu uzete površine neobraslog ineplodnog šumskog zemljišta. Podaci su dobivenijednostavnim matematièkim metodama iz Osnovagospodarenja gospodarskim jedinicama. Iakodijelovi nekih gospodarskih jedinica nisu u sastavuParka prirode Lonjsko polje, ipak su uzete u cijelosti.

The information in the graphic display (Graph 1)shows the distribution of age classes of thecommercial forests over the area of the Nature Parkand environs. Areas of forest land not covered orunfertile are not taken into consideration. The dataare obtained by the simple mathematical methods ofthe Management Plan for the management units.Since parts of some management units are notactually within the official limits of Lonjsko PoljeNature Park, they are nevertheless taken as wholes.


51



Grafièki prikaz (grafikon 1.) jasno pokazujenedostatak dijela mladih šuma, i to drugog dobnograzreda, u ukupnoj površini od 2478,46 ha, te dijelasrednjodobnih šuma, i to treæeg dobnog razreda, uukupnoj površini od 1608,13 ha, te èetvrtoga dobnograzreda, u ukupnoj površini od 1104,12 ha.Jedan od primjera veoma lošeg rasporeda dobnihrazreda na podruèju parka prirode Lonjsko poljenalazimo u gospodarskoj jedinici Meðustrugovi.

Grafikon 2.

The graphic display of Graph 1 clearly shows theinsufficiency in respect of young forests, particularlyof the second age class, in a total area of 2478.46 ha,and of medium age forests, in the third age class,over a total area of 1608.13 ha, and the fourth ageclass, in a total area of 1104.12 ha.One example of a very poor distribution of ageclasses in the area of Lonjsko Polje Nature Park isthe Meðustrugovi Management Unit.

Graph 2

Na podruèju te gospodarske jedinice 78,50% šuma u5. je i 6. dobnom razredu, a samo 21,5% u svimostalim dobnim razredima. Ako uzmemo u obzir dasu šume na podruèju te gospodarske jediniceuglavnom šume poljskog jasena, zakljuèujemo dase prema zakonskim odredbama za 51,48% tih šumamo�e propisati dovršni sjek. Osnova gospodarenjaza razdoblje I/I (1998. - 2007.) propisuje dovršni sjekna ukupnoj površini od 428,44 hektara. Iz propisaOsnove gospodarenja proizlazi da je površinapredviðena za obnovu veæa od normalne površinedobnog razreda za 40,42% ili za 123,33 hektara.

In the area of this management unit, 78.5% of theforest is in the 5th and 6th age class, and only 21.5%of the forest in all other age classes combined. If wetake into consideration the forests in thismanagement unit being mainly of narrow-leavedash, we can conclude that according to the currentlyvalid legal provisions, 51.48% of this forest can beset for final cut. The currently valid ManagementPlan for the I/I Period (1998-2007) prescribes finalcut over a total area of 427.44 hectares. From theregulations of the Management Plan it can be seenthat the area set aside for regeneration is greaterthan the normal area of the age group by 30.42% or123.33 ha.





Grafikon 3. Graph 3

�abarski bok je gospodarska jedinica koja napodruèju PPLP ima najpovoljniji raspored dobnihrazreda po površini. Samo se u 6. dobnom razredupokazuje znatan nedostatak šuma starih od 101 do120 godina, i to na površini od 55,18 hektara.Osnova gospodarenja propisuje obnovu, odnosnodovršni sjek u odsjecima 11a i 15a, na ukupnojpovršini od 24,09 hektara. U buduænosti æe se u tojgospodarskoj jedinici vrlo brzo postiæi normalanraspored dobnih razreda po površini.Nepovoljan razmjer dobnih razreda ima višene�eljenih posljedica. Najdrastièniji primjer štetnihposljedica za krajobraznu i biološku raznolikost zbognepovoljnih razmjera dobnih razreda na podruèjuParka prirode Lonjsko polje nalazimo uGospodarskoj jedinici Zelenika, u šumskom predjeluZelenika.

Na karti (karta 1.) uoèava se da je veliki kompleksšuma iste starosti, odnosno 7. i 8. dobnog razreda.Takoðer su odsjeci Ureðajnoga razreda poljskogjasena u 5. dobnom razredu (prema karti 1.) pasamim tim pri sljedeæoj reviziji Osnove sigurno ulazeu pomladno razdoblje. Odsjek 11 a dovršnim jesjekom posjeèen 1986. Prirodna obnova u tom jeodsjeku veoma ote�ana zbog niza èimbenika, takoda je i u 2004. godini ovdje planirana pripremastaništa i pošumljivanje na površini od nekih 11hektara. Prema zakonskim propisima, u šumama 7. i8. dobnoga razreda mogu se zapoèeti radoviprirodne obnove, odnosno u zadnjoj fazi obnovesijeku se dovršnim sjekom. Pravilnik o ureðivanjušuma u èlanku 20.(Narodne novine br.11 od 11. I.1997.) propisuje donju granicu ophodnje, za hrast

�abarski bok is the management unit that has themost favourable distribution of age groups over thearea in the area of Lonjsko Polje Nature Park. Onlyin the 6th age class is there a sensible absence offorests 101-120 years old, on an area of 55.18 ha.The current Management Plan prescribesregeneration, or final cut in compartments 11a and15a with an overall area of 24.09 ha. In the future, anormal distribution of age classes over the area inthis management unit will very rapidly be achieved.

An unfavourable ratio of age classes is attended by anumber of undesirable consequences. The bestexample of the harmful consequences for landscapeand biological diversity because of the unfavourableratio of age classes in the area of Lonjsko PoljeNature Park is in the Zelenika Management Unit inthe Zelenika forest area.

From this map (Map 1) it can be seen that there is alarge complex of forests of the same age, that is ofthe 7th and 8th age classes. Also the compartmentsof the management class of narrow-leaved ash arein the 5th age class (according to Map 1) and hencein the next review of the plan will certainly come intothe regeneration domain. Compartment 11 wassubject to final cut in 1985. Natural regeneration isvery much hindered in this compartment, because ofa number of factors, and hence in 2004 in thiscompartment habitat preparation and afforestationover an area of ca 11 ha were planned. According tocurrent legal regulations, works on naturalregeneration can be started in forests in the 7th and8th age classes, that is, in the last phase ofregeneration they are felled with final cut. TheForest Management Regulations, Article 20 (OfficialGazette no. 11, January 11, 1997) prescribes thelowest level of a rotation for common oak of 140


53



lu�njak 140 godina, a za poljski jasen 80 godina.Revizija Osnove gospodarenja za gospodarskujedinicu Zelenika izvršena je 1996. i vrijedi od 1996.do 2005. Ona propisuje prirodnu obnovu, odnosnodovršni sjek u šumskom predjelu Zelenika uodsjecima 2a, 3a, 6a, 6b, 7a, 7e, 10a, 13b, 14a, 15a,15b, 16a, 17a, 18c, kojima ukupna površina iznosi438,83 hektara. Do 2004. izvršenjem Osnoveposjeèeni su dovršnim sjekom odsjeci 2a, 6a, 6b,7a, 7e, 18c, a u tijeku je sjeèa odsjeka 10a, koji jenajveæi u tom kompleksu i ima površinu od 77,31hektar. Naplodni sjek je izvršen u odsjeku 15a i u polaodsjeka 13b, sjeèa na pruge izvršena je u odsjecima14a, 16a, 17a i u polovici odsjeka 13b. U odsjeku 15bjoš nisu zapoèeli radovi prirodne obnove. Osnovagospodarenja za gospodarsku jedinicu Zelenikapropisuje dovršni sjek na površini od 657,34 ha.Kako normalna površina dobnog razreda iznosi215,14 hektara, propisom Osnove gospodarenjapovršina za obnovu je za 205,5% ili za 442,20hektara veæa od normalne površine dobnog razreda.Naplodni sjek je izvršen na površini od 83,29hektara, što znaèi da æe i te površine u vrlo kratkomvremenu, ovisno o uspjehu prirodne obnove (3 - 5godina), biti dovršno posjeèene, a to je sa stajalištakrajobrazne vrijednosti podruèja svakako loše jer je uvrlo kratkom vremenu nestalo starih hrastika na,uvjetno reèeno, velikoj površini. Kad govorimo o sjeèina velikoj površini sa stajališta uzgajanja šuma,sjeèa na velikoj površini je sjeèa cijelog odsjeka.S druge strane, nestanak tako velikog kompleksastarih šuma mo�e uzrokovati zamoèvarivanje terenajer se u velikoj mjeri smanjuje transpiracijskapovršina. U velikoj mjeri se narušava bioraznolikostjer s nestankom stare šume nestaju sa tog podruèjasve vrste koje ovise o staroj šumi, bilo da im je onaprijeko potrebna za gnije�ðenje (orao štekavac, crnaroda, orao kliktaš, djetlovi) ili im pru�a zaklon ihranilište. Velik broj vrsta šišmiša koristi se starimšumama, i to na naèin koji zahtijeva slo�enustrukturu pristupaènih stabala s dupljama, ali imikrostanišne uvjete. Raznolikost �ivotinjskih ibiljnih zajednica, pojednostavnjeno reèeno,razmjerna je kolièini starih šumskih sastojina, a uz toi dodatno poveæava mozaiènost staništa i postojanjedodirnih pojasa izmeðu dvaju tipova staništa.

Na karti (karta 2.) je uoèljivo da je rijeè o kontinuiranojpovršini na kojoj nema odsjeka stare šume izmeðuposjeèenih površina.

years, and for narrow-leaved ash of 80 years.The review of the management plan for ZelenikaManagement Unit was addressed in 1996, and theperiod in which this plan is valid is 1996-2005. Thecurrent Management Plan prescribes naturalregeneration or final cut in the forest area of Zelenikain Compartments 2a, 3a, 6a, 6b, 7a, 7e, 10a, 13b,14a, 15a, 15b, 16a, 17a, 18c, the total area of whichcomes to 438.83 ha. Up to 2004, in theimplementation of the plan, compartments 2a, 6a,6b, 7a, 7e and 18c were felled in the final cut, and thefelling of Compartment 10a is under way, the largestof all the compartments in this area, with an area of77.31 ha. Seeding cut has been carried out inCompartment 15a and in half of Compartment 13b,strip cuttinghas been carried out in Compartments14a, 16a, 17a and in half of Compartment 13b. InCompartment 15b works on natural regenerationhave not yet been started. The Management Plan forZelenika Management Unit prescribes final cut overan area of 657.34 ha. Since the normal area of theage class comes to 215.14 hectares according theregulations of the Management Plan, theregeneration area is 205.5% or 442.2 hectaresgreater than the normal area of the age class.Seeding cut has been carried out over an area of83.29 ha, which means that the land will in a veryshort period of time, depending on the success ofnatural regeneration (2-5 years), will be subject tofinal cut, which is from the point of view of thelandscape value of the area very bad, since in a veryshort time the old oak forests will have vanished onwhat might be called a large area. When we aretalking of felling over a large area, from thestandpoint of silviculture, felling over a large area isthe felling of a whole compartment.On the other hand the absence of such a largecomplex of old forests can lead to the marshificationof the land because the transpiration of the land isreduced to a great extent. Also to a great extent, thebiodiversity of the area is disturbed because whenan old forest disappears, all the species that dependon old forests also vanish, whether it is essential fortheir nesting (sea eagle, black stork, white-tailedeagle, woodpeckers) or whether it is a refuge orfeeding area. A large number of species of bats usethe old forests, in a manner, what is more, thatrequires a complex structure of accessible hollowtrees, as well as micro-habitat conditions. Thediversity of animal and plant species, put in asimplified way, is proportional to the quantity of oldforest stands, and also additionally increases themosaic nature of the habitats and the existence ofcontact zones between two types of habitat.

Map 2 shows that this is a continuous area in whichthere are no old forest compartments between thefelled areas.





Rasprava i zakljuèak

Postavlja se sljedeæe pitanje:Kako se vidi gospodarenje u buduænosti kada tešume doðu u fazu obnove?

Grafièki prikaz razmjera dobnih razreda pokazuje dasu površine zadnjih dobnih razreda, šume koje æe popropisima uæi u fazu prirodne obnove, veæe odnormalnih površina dobnih razreda. To znaèi da æe sesigurno ponoviti situacije kad Osnova gospodarenjapropisuje u jednom polurazdoblju obnovu šuma nakontinuiranoj površini velièine 200 i više hektara.Takve situacije su svakako nepovoljne i sigurno imajunesagledive posljedice za krajobraznu i biološkuraznolikost i za stabilnost ekosustava.Takoðer treba spomenuti i gospodarski uèinaksmanjenja površina koje æe se sjeæi dovršnim sjekomu buduænosti. Smanjene površine dovršnih sjekovanu�no uzrokuju smanjenu sjeèivu drvnu masu, asamim tim i manji financijski uèinak. Kako æe se ubuduænosti nadomjestiti nedostatak novcazaraðenog dovršnim sjekovima?Pitanje koje se èesto postavlja svakako je i duljinaophodnje hrasta lu�njaka.

Lu�njakove šume u Hrvatskoj danas su zbog vrlojakih antropogenih utjecaja:

- loše provedene regulacije vodnih tokova imelioracije (sni�avanje razine podzemnih vodai promjene u prirodnom ritmu poplava)

- kazetiranja terena mre�om tvrdih cesta, s lošimpropustima (zabarivanje terena)

- zatrovane i oneèišæene vode Save- optereæenosti oneèišæenim zrakom (SO , NOx,

teški metali i dr.)i zbog raznih biotskih utjecaja:

- epidemijsko ugibanje nizinskog brijesta- sve èešæa sušna razdoblja tijekom vegetacije- slabljenjem otporne snage drveæa dolazi do

napada štetne entomofaune, ponajviše gubara,i biljnih bolesti, u prvom redu pepelnice

- loše gospodarenje u prošlosti (velike sjeèe,monokulture hrasta lu�njaka),

promijenile svoj prirodni izgled i prirodnu stabilnost. Utom svjetlu svakako treba razmotriti pitanje je li opæaodredba da je ophodnja hrasta lu�njaka u Hrvatskoj140 godina danas prihvatljiva. Treba razmotritizamisli da se ophodnja utvrðuje prema zdravstvenomstanju i opæoj vitalnosti konkretne šume, odnosnokonkretnog odsjeka kao najmanje površine kojom segospodari.Produljenjem ophodnja zdravih i vitalnih hrastika teuspostavom normalnog razmjera dobnih razreda popovršini svakako bi se pridonijelo oèuvanju, zaštiti i

�

2

Discussion and Conclusion

The following question arise.How is management envisaged in the future inwhich these forests enter the regeneration phase?

The graphic display of the dimensions of the ageclasses shows that the area of the last age classes,of forest that according to the current regulationsshould come into the natural regeneration phase,are greater than the normal areas of age classes.This means that the situation will certainly arise inwhich the Management Plan prescribes, in a singlehalf-period, the regeneration of the forest over acontinuous area of 200 and more hectares in area.Such situations are very unfavourable and willcertainly have incalculable consequences for thelandscape and biological diversity and for thestability of the ecosystems.It is also necessary to mention the economic effect ofthe reduction of areas that are cut with final cuts inthe future. Reduction of area of final cutsnecessarily brings about a reduction of wood massfor felling, and hence the financial performance.How in the future will it be possible to make up theabsence of the financial resources acquired throughfinal cuts?A question that is often asked is the length of thecommon oak rotation.

Common oak forests have certainly changed theirnatural appearance and natural stability because ofvery powerful anthropogenic factors:

- poorly executed water-course engineering andreclamation (lowering the level of theunderground water and changes in the naturalrhythm of flooding);

- the compartmentalisation of the land with anetwork of hard roads with poor permeability(the land becomes marshy);

- pollution and toxification of the Sava water;- the burden of polluted air (SO , NOx, heavy

metals and so on)as well as because of various biotic influences:

- the epidemic mortality of lowland elm- increasingly frequent periods of drought during

vegetation- weakened resistance of trees leads to harmful

attacks of insect pests, primarily of the gypsymoth and plant sicknesses, primarily blight,

- bad management in the past (large cuts,common oak monoculture).

In this light one should certainly consider thequestion of whether the general provision that therotation of common oak in Croatia should be 140years is acceptable today. One should consider theideas that the rotation should be laid down accordingto the state of health and the general vitality of theconcrete forest, or the concrete compartment, the

�

2


55



poveæanju vrijednosti šuma na podruèju Parkaprirode Lonjsko polje. Hrastike koji su u lošem stanju,koji se suše na veæim površinama, pa se tloprekomjerno zakorovljuje, svakako treba obnoviti iprije. Trebalo bi takoðer razmotriti, s obzirom nanovonastale stanišne uvjete u nekim šumama, je lihrast vrsta koja u njima i dalje mo�e rasti ili ipak trebasvoje mjesto prepustiti poljskom jasenu i obrnuto. Ikrajobrazne bi vrijednosti bile puno bolje oèuvaneako bi se dovršnim sjekom sjekle manje površine udu�im vremenskim razmacima.Prema propisanim Uvjetima zaštite prirodeMinistarstva zaštite okoliša i prostornog ureðenja (od16. VIII. 2002. Ur.br.531-06/2-�Š-02-4) na podruèjuParka prirode Lonjsko polje prilikom dovršnog sjekatreba ostaviti najmanje 1 stablo po hektaru i svevoækarice. Ti se uvjeti poštuju u gotovo svimodsjecima, ali s obzirom na to da je ovdje površinadovršnog sjeka ukupno velika, dr�imo da je jednostablo po hektaru nedovoljno. U takvim sluèajevima,koje u buduænosti svakako treba nastojati izbjeæi,trebalo bi ostavljati nekoliko veæih grupa stabalapovršine do 1 hektar ravnomjerno rasporeðenih popovršini. U tom sluèaju te veæe grupe slu�ile bi kaootoci stare šume na èistinama dok se mlada šuma nerazvije, a to je razdoblje od 20 do 40 godina.Postavlja se èesto pitanje što sa tim stablima kada semlada šuma razvije. Dr�imo da takva stabla trebaprepustiti njihovu prirodnom ciklusu starenja iumiranja.Da bi se postigao što bolji pravilan raspored dobnihrazreda po površini i oèuvala biološka i krajobraznaraznolikost, trebalo bi razmotriti izmjene Zakona ošumama i Pravilnika o ureðivanju šuma. Izmjene bisvakako trebale obuhvatiti moguænosti pomakasjeène dobi zdravih i vitalnih šuma i velièinu sjeèina uzaštiæenim podruèjima.

smallest area that is managed.Prolongation of the rotation of healthy and vital oakforests and the establishment of the normaldimension of the age groups over the area wouldcertainly contribute to the conservation, protectionand augmentation of the value of the forests in thearea of Lonjsko Polje Nature Park. Oak woods thatare in a poor state, in which mortality has occurredover large areas and in which the ground hasbecome excessively weedy should certainly also beregenerated earlier. One should also consider thequestion, because of the new habitat conditions thathave arisen in some of the forests, of whether theoak is a species that can continue to grow here orwhether it should after all give ground to the narrow-leaved ash and vice-versa. In addition, landscapevalues would be much better preserved if smallareas were subject to final cuts over longer periodsof time. According to the regulation NatureProtection Conditions set by the Ministry ofEnvironmental Protection and Physical Planning(August 16 2002, ref. no. 531-06/2-ZS-02-4), duringfinal cuts in the area of Lonjsko Polje Nature Park atleast 1 tree per hectare should be left, and all the fruittrees. These conditions have been respected inalmost all the compartments, but considering thatthe area of final cut is very large here, we think thatone tree per hectare is not enough. In cases of thisnature, which should certainly be avoided in thefuture, some larger groups of trees of areas of 1hectare evenly distributed over the land shouldcertainly be left. In this case these larger groupswould serve as islands of old forest on the clearedland, until the young forest develops, in a period from20 to 40 years. The question also is often asked asto what should be done with such trees when theyoung forest has grown. We are of the opinion thatsuch trees should be left to their natural cycle ofaging and dying.In order the better to achieve the proper distributionof age classes over the land and the preservation ofbiological and landscape diversity, it is necessary toconsider changes in the Forests Law and the ForestManagement Regulations. Modifications shouldcertainly cover the possibility of moving the fellingage of health and vital forests and the dimensions ofthe cut in conservation areas.






57

Slika 1.

Figure 1.

Stari hrastici u Slavoniji poèetkom prošlog stoljeæaOld oak forests in Slavonia at the beginning of the last century.

Literatura:

Osnova gospodarenja Gospodarskom jedinicom "Brezovica" - 1997.-2006.

Osnova gospodarenja Gospodarskom jedinicom "Popovaèke nizinske šume" - 1999. -2008.

Osnova gospodarenja Gospodarskom jedinicom "Kutinske nizinske šume" - 2001.-2010.

Osnova gospodarenja Gospodarskom jedinicom "Lonja" - 1999.-2008.

Osnova gospodarenja Gospodarskom jedinicom "Josip Kozarac"-1995.-2004.

Osnova gospodarenja Gospodarskom jedinicom "�abarski bok" - 2003.-2012.

Osnova gospodarenja Gospodarskom jedinicom "Krapje ðol" - 2001.-2010.

Osnova gospodarenja Gospodarskom jedinicom "Trstika" - 2001.-2010.

Osnova gospodarenja Gospodarskom jedinicom "Zelenika" - 1996.-2005.

Osnova gospodarenja Gospodarskom jedinicom "Grede - Kamare" - 1996.-2005.

Osnova gospodarenja Gospodarskom jedinicom "Meðustrugovi" - 1998.-2007.

Pravilnik o ureðivanju šuma (Narodne novine br.11/97).

Zakon o šumama(Narodne novine br.52/90)

Ureðivanje sastojina hrasta lu�njaka ošteæenih sušenjem - terenski kolokvij

Šumarska enciklopedija

D. Klepac, Ureðivanje šuma, Zagreb 1965.

Prijedlog Prostornog plana podruèja posebnih obilje�ja PPLP

Dra�en Ivaštinoviæ, dipl. ing. šum.JUPP Lonjsko polje

Struèna slu�baTrg kralja P. Svaèiæa bb, Jasenovac



PROPADANJE STABALA IPOREMETNJA STABILNOSTINIZINSKIH ŠUMSKIHEKOSUSTAVA

SA�ETAK

1.Uvod

1.1. Nizinski šumski ekosustavi

U radu je obraðena problematika funkcioniranja,razvoja i postojanosti nizinskih šumskih ekosustava.Posebno su rašèlanjene dosadašnje spoznajeuzroka poremetnje postojanosti tih ekosustava iprikazana je dinamika odumiranja stabala hrastalu�njaka i poljskog jasena. Usporeðena je dinamikapropadanja stabala hrasta lu�njaka s mikrostanišnimuvjetima i dobi sastojina. Na primjeru gospodarskejedinice Opeke prvi put je utvrðeno veæe propadanjestabala hrasta lu�njaka na mikrouzvisini (gredi) negona mikroudubini (nizu), kao i veæa uèestalost, veæiintenzitet propadanja stabala V. dobnog razredanego onih VI. dobnog razreda. U radu se raspravlja i ouzrocima propadanja stabala, s naglaskom naklimatskim ekscesima i drugim promjenamaekoloških uvjeta.

Funkcioniranje šumskih ekosustava ovisi o dinamicirasta i razvoja organizama, suparništvu meðuvrstama i unutar vrsta u borbi za prostor, hranu isvjetlo, kao i o njihovoj prilagodbi na stalne promjeneekoloških uvjeta. Opstanak i razvoj šumskihekosustava nadalje ovise o prirodnoj ravnote�i iotpornosti na razlièite nepovoljne utjecaje (Seletkoviæi Tikviæ, 1998.). Kako su šumski ekosustavi �ivotnezajednice biljaka, �ivotinja i mikroorganizama ukojima drveæe i druga drvenasta vegetacija odreðujustrukturne i funkcionalne odnose na odreðenomstaništu i pri odreðenim ekološkim uvjetima,promjene prirodne biološke i ekološke ravnote�erezultiraju poremetnjom stabilnosti i degradacijomšumskih ekosustava (Tikviæ, 2001.). Promjenebioloških i ekoloških uvjeta u prvom su reduuzrokovane èovjekovim djelovanjem. Posljedica tihpromjena je fiziološko slabljenje i propadanje stabalahrasta lu�njaka i drugih vrsta drveæa, što je osobitonaglašeno u 20. stoljeæu (König, 1911.; Vajda, 1968.;Prpiæ, 1988.).

Osnovno obilje�je nizinskim šumskim ekosustavimau Hrvatskoj daju hrast lu�njak, obièni grab, poljskijasen i crna joha te specifièni ekološki uvjeti u kojima

DIEBACK AND DISTURBANCEOF THE STABILITY OF THELOWLAND FORESTECOSYSTEMS

SUMMARY

1. Introduction

1.1 Lowland forest ecosystems

This paper deals with the problems of the functions,development and stability of lowland forestecosystems. Particular analysis is made of theknowledge gained to date into the causes of thedisturbance of these ecosystems and the dynamicswith which common oak and narrow-leaved ash treesdie are given. The dynamics of dieback in commonoak trees is considered with reference to themicrohabitat conditions and the age of the stand.Using the Opeka Management Unit (MU), the greaterdieback of common oak trees on the micro-elevationsas against the micro-depressions was established,as well as a greater intensity of dieback of trees of the5th cohort as against the 6th cohort. The reasons fordieback are discussed, with the emphasis on climaticextremes and other changes of ecological conditions.

The functioning of forest ecosystems depends onthe dynamics of growth and the development of theorganisms, inter-species and intra-speciescompetition for space, nutrients and light, andadaptation to the constant changes of the ecologicalconditions. The survival and development of theforest ecosystems in turn depends on the naturalbalance and the resistance to various deleteriousimpacts (Seletkoviæ and Tikviæ, 1998). Since forestecosystems are living communities of plants,animals and microorganisms, in which trees andother woody vegetation determine the structural andfunctional relations in a given habitat and in givenecological conditions, changes of the naturalbiological and ecological equilibrium result in thedisturbed stability and he degradation of the forestecosystems (Tikviæ, 2001). Changes in biologicaland ecological conditions are primarily broughtabout by human activities. The consequence ofthese changes is the physiological decline anddieback of common oak trees and other kinds of treespecies, particularly noted in the 20th century(Konig, 1911; Vajda, 1968; Prpiæ, 1988).

The basic characteristics of the lowland forestecosystems in Croatia are provided by the commonoak, European hornbeam, narrow-leaved ash andblack alder, and by the specific ecological conditionsin which some of the species are dominant. The





pojedine vrste prevladavaju. Hrast lu�njak uHrvatskoj zauzima oko 10% šumske površine,odnosno 210 000 ha (Matiæ, 2000.). Dolazi u nekolikotipiènih šumskih zajednica mješovite strukture, kojese meðusobno razlikuju po hidrološkim, orografskim,edafskim, klimatskim i drugim uvjetima (Vukeliæ iRauš, 1998.). Presudno utjeèu na razvoj tihzajednica hidrološke prilike koje znatno ovise omikroreljefu. Hidrološki odnosi u nizinskim šumskimekosustavima uvjetovani su dinamikom poplavne,podzemne i oborinske vode. Poplavna i podzemnavoda nadalje ovise i o dvama glavnim oblicimamikroreljefa koji se pojavljuju u nizinskim šumskimekosustavima, a to su mikrouzvisine i mikroudubine.Glavne razlike u hidrološkim prilikama tih dvaju oblikamikroreljefa su u pojavi i trajanju poplave, te udinamici i razinama podzemne vode. Utjecaj èovjekau posljednjih nekoliko stoljeæa jedan je odnajznaèajnih èimbenika koji mijenja odnose unizinskim šumskim ekosustavima, što se odra�avana njihov razvoj i stabilnost (Seletkoviæ i Tikviæ, 1996).

Dinamika odnosa i procesa u nizinskim šumskimekosustavima ovisi o biotskim i abiotskimèimbenicima. Voda je najva�niji abiotski èimbenik ipromjene vodnih odnosa odra�avaju se na njihovustabilnost, proizvodnost i obnovu (Prpiæ, 2001.;Starèeviæ, 2003.). Stabilne vrste lako podnoseodreðene nepovoljne utjecaje pa se razvojekosustava ne mo�e znatnije poremetiti djelovanjemekstremnih prirodnih pojava. Stabilnost prema tomeovisi o otpornosti i elastiènosti i postojanosti.Otpornost vrsta ili sustava je zadr�avanjenepromijenjena stanja nakon djelovanja nepovoljnihutjecaja. Elastiènost je brzina povratka u stanjeravnote�e nakon odreðenih poremeæaja, apostojanost vrijeme u kojem se sustav nalazi prijepromjene u neki drugi sustav. Stabilnost šumskihekosustava izra�avamo zdravstvenim stanjem,vitalnošæu stabala i intenzitetom propadanja stabala.Vitalnost stabala procjenjuje se na temelju vanjskogizgleda stabala, tj. na temelju procjene osutostikrošanja i promjene boje lišæa ili iglica u usporedbi sdogovorenim referentnim stanjem, odnosno utvrðujese postotak osutosti krošanja u odnosu na normalnorazvijenu krošnju iste vrste drveæa u sliènimekološkim i sastojinskim uvjetima (manual ICP-Forests, 1998.; Forest Health Monitoring, 1998.).Vitalnost stabala je pokazatelj poremetnje fiziološkeaktivnosti stabala koja pod djelovanjem brojnihstresnih èimbenika odumiru.

1.2. Stabilnost šumskih ekosustava

common oak occupies about 10% of the forest areain Croatia, that is about 210,000 ha (Matiæ, 2000). Itis found in several typical forest communities ofmixed structure that are differentiated according tohydrological, orographic, edaphic, climatic and otherconditions (Vukeliæ and Raus, 1998). Acritical role inthe development of such communities is played byhydrological conditions, which are in turn verydependent on the microrelief. Hydrological relationsin the lowland forest ecosystems are determined bythe dynamics of flood, underground and runoffwaters. Flood and underground water are furtherdependent on two main forms of microrelief thatappear in the lowland forest ecoystems, that is,micro-elevations and micro-depressions. The maindifferences in the hydrological conditions of thesetwo forms of microrelief are in the occurrence andduration of the flooding, and in the dynamics andlevels of the underground water. The influence ofpeople in the last few centuries has been one of themost important factors changing the relationships inthe lowland forest ecosystems, which is reflected intheir development and stability (Seletkoviæ andTikviæ, 1996).

The dynamics in the relations and processes in thelowland forest ecosystems depends on biotic andabiotic factors. Water is the most important abioticfactor, and changes in aqueous relations arereflected in stability, production and regeneration(Prpiæ, 2001; Starèeviæ, 2003). Stable specieseasily tolerate certain adverse influences and thedevelopment of an ecosystem cannot be disturbedin a major way by the action of extreme naturalphenomena. Stability accordingly depends onresistance, elasticity and persistence. Theresistance of species or systems represents themaintenance of the unmodified state of affairs afterthe action of adverse influences. Elasticity is thespeed of return to the situation of balance after givendisturbances, and persistence the time in which thesystem exists before change to some other system.The stability of forest ecosystems is expressed bythe state of health, the vitality of trees and theintensity of dieback in the trees.The vitality of trees is estimated according to theexternal appearance of the tree, i.e., on the basis ofthe estimate of the defoliation of crowns andchanges in the colour or leaf or needle as against anagreed reference state, or the percentage ofdefoliation of crowns as against a normallydeveloped crown of the same kind of tree in similarecological and stand conditions (ICP ForestsManual, 1998; Forest Health Monitoring, 1998). Thevitality of the tree is an indicator of the disturbance ofthe physiological activity of trees that, when affectedby too many stress factors, will die off.

1.2 The stability of the forest ecosystems


59



1.3. Propadanje stabala

Problem propadanja stabala u nizinskim šumskimekosustavima aktualan je veæ više od jednogstoljeæa. Taj problem jednako zaokuplja šumarepraktièare i znanstvenike (Kozarac, 1897.;Kovaèeviæ, 1928.; Nenadiæ, 1940.; Dekaniæ, 1972.;Androiæ, 1975.; Prpiæ, 2003.). Propadanje stabala ušumskim ekosustavima posljedica je konkurencijevrsta i individua; djelovanja razlièitih prirodnih pojava(klimatski ekscesi: grom, vjetar, mokar snijeg, ledenakiša, suša, dugotrajna poplava, biotski èimbenici);promjena ekoloških uvjeta (promjene hidrološkihprilika, tj. sni�avanja razina podzemne vode,promjena dinamike poplavne vode, zamoèvarenja iisušivanja staništa, oneèišæenje poplavne i oborinskevode) i nepovoljna utjecaja èovjeka. U nizinskimšumskim ekosustavima, po veæini dosadašnjihspoznaja, propadanje stabala je uzrokovano u prvomredu promjenama ekoloških uvjeta i nepovoljnimutjecajima èovjeka. Kada propadanje stabalapoprima velike razmjere, ono utjeèe na stanje šuma,njihov rast, razvoj i obnovu, odnosno gospodarske iopæekorisne vrijednosti. Razlikujemo pojedinaènopropadanje, propadanje skupina stabala i masovnopropadanje stabala. Propadanje stabala jepokazatelj poremetnje u funkcioniranju šumskihekosustava, naznaka kompleksnog djelovanjanepovoljnih èimbenika koji imaju kumulativni isinergistièki uèinak. Ono se razlikuje i prema brzini iintenzitetu, te mo�e biti postupno i brzo. Postojerazlike i u intenzitetu propadanja stabala, parazlikujemo mali, znaèajan i katastrofalan intenzitetpropadanja stabala. Propadanja stabala se izra�avau apsolutnim vrijednostima (m , m /ha) i postotnojvrijednosti odumrlih stabala u odnosu na drvnu zalihupo jedinici površine (intenzitet propadanja).Propadanje hrasta lu�njaka prema Prpiæu (1974.) jeznaèajnije u srednjodobnim i starijim sastojinama,dok su se mlaðe sastojine prilagodile promjenama ustaništu. Èimbenici koji izazivaju propadanje stabalasu biotski, sastojinski i stanišni (Vajda, 1968.). Odbiotskih èimbenika posebno su utjecajne biljnebolesti, štetni kukci i divljaè; od sastojinskihèimbenika na intenzitet propadanja utjeèe naèinpostanka sastojina (prirodni ili umjetni), staroststabala i struktura sastojine (èista ili mješovita). Unizinskim šumskim ekosustavima uoèava sefiziološko slabljenje i propadanje stabala gotovo svihvrsta drveæa (Prpiæ, 1996.; Matiæ, 2000.). Meðutim,vrlo je teško razluèiti primarne od sekundarnih itercijarnih uzroka koji dovode do propadanja,poremetnje stabilnosti i degradacije tih ekosustava.

3 3

1.3 Dieback in trees

The problem of dieback in trees in lowland forestecosystems has been an issue for more than acentury. This problem has occupied the attention ofpractical forestry workers and academicresearchers (Kozarac, 1897; Kovaèeviæ, 1928;Nenadiæ, 1940; Dekaniæ, 1972;Androiæ, 1975, Prpiæ,2003). The dieback of trees in forest ecosystemsoccurs as a result of competition of species andindividuals; the action of various natural phenomena(climatic extremew such as lightning, wind, wetsnow, freezing rain, drought, long-lasting floods,biotic factors), as a result of changes in ecologicalconditions (changes in hydrological conditions, i.e.,the dropping of the level of underground water,changes in the dynamics of floodwaters, the drainingof the habitat or its being turned into marshland,pollution of the flood and run-off waters) and theadverse impact of people. In lowland forestecosystems, according to most understandings todate, dieback is caused primarily by changes in theecological conditions and adverse anthropogenicfactors. When the dieback of the trees assumesmajor proportions, it affects the condition of theforests, their growth, development andregeneration, or their economic and general-usevalues. We differentiate the dieback of individualtrees, then the dieback of groups of trees and themass dieback of the woods. The dieback of trees isan indicator of a disturbance in the functioning offorest ecosystems, a hint of the complex actions ofadverse factors that have a cumulative andsynergistic effect. It is further differentiatedaccording to speed and intensity, and can be gradualand rapid. There are differences in the intensity oftree dieback, and we distinguish a small,considerable and catastrophic intensity of treedieback. Tree dieback is expressed in absolutevalues (m , m /ha) and percentage value of timberstocks per unit of area (intensity of dieback). Thedieback of common oak according to Prpiæ (1974) ismore important in medium-age and older stands,while the younger stands have adapted to changesin the habitat. Factors that bring about tree diebackare biotic, stand-related and habitat-related (Vajda1968). Particularly important in the biotic factors areplant diseases, harmful insects and game; of thestand-related factors, the following have a particularimpact on the intensity of dieback: whether the standwas created artificially or naturally, the age of thetrees and the structure of the stand (pure or mixed).In the lowland forest ecosystems physiologicalweakening and dieback of trees in almost all speciescan be seen (Prpiæ, 1996; Matiæ, 2000). However, itis very difficult to distinguish primary from secondaryand tertiary causes leading to dieback, disturbanceof the stability of and degradation of theseecosystems.

3 3





2. Podruèje istra�ivanja

3. Metoda rada

4. Rezultati

Istra�ivanje je provedeno u nizinskim šumskimekosustavima hrasta lu�njaka i u gospodarskojjedinici Opeke Nastavno-pokusnog šumskog objekta(NPŠO) Lipovljani, Šumarskog fakulteta Sveuèilišta uZagrebu. Gospodarska jedinica (g. j.) Opeke spovršinom od 547 ha reprezentativni je predstavniknizinskih šuma s hrastom lu�njakom, obiènimgrabom, poljskim jasenom i crnom johom kao glavnimvrstama šumskoga drveæa. To je podruèje oko 5 kmju�no od autoceste Zagreb - Beograd, u blizini selaKraljeva Velika i Lipovljani, oko 15 km jugoistoèno odKutine. Hidrološke prilike tih šumskih ekosustavaznatno ovise o rijeci Savi, koja teèe oko 5 km ju�no odobjekta, i njezinim lijevim pritokama (Trebe� i VelikiStrug). Reljef je tipièno nizinski, blago valovit, sizra�enim mikrouzvisinama i mikroudubinama,nadmorske visine od 93 do 99 m. Sastojine sumješovite, s udjelom hrasta lu�njaka u omjeru smjese60 - 70%, poljskog jasena 15 - 25%, a ostalo su drugevrste drveæa. Dob sastojina je od 105 do 150 godina.

Na temelju doznake odumrlih stabala (»sušaca«)hrasta lu�njaka i poljskog jasena u g. j. Opeke obraðenisu podaci o ukupnim drvnim masama odumrlih stabalahrasta lu�njaka i poljskog jasena za razdoblje 1986. -2003. Kako intenziteti propadanja stabala znatno oviseo stanišnim èimbenicima, izdvojeni su iz knji�icadoznake odjeli iz dva razlièita mikrostaništa u kojima jezabilje�eno propadanje stabala s pribli�no podjednakepovršine. Napravljene su analize drvne mase odumrlihstabala po jedinici površine (ha), zatim usporeðenevrijednosti ukupne drvne mase odumrlih stabala pomikrostaništima i dobnim razredima.

Drvna mase odumrlih stabala hrasta lu�njaka ipoljskog jasena u g. j. Opeke NPŠO Lipovljani ugodinama 1986. - 2003. znaèajno se mijenja. Nagrafikonu 1 uoèavaju se dva maksimuma odumiranjastabala, od kojih je prvi obilje�en velikimodumiranjem stabala hrasta lu�njaka i poljskogjasena, dok kod drugog maksimuma prevladavasušenje hrasta lu�njaka. Prema grafikonu 5 uoèavajuse promjene dinamike podzemnih voda za godine ukojima se pojavilo maksimalno odumiranje stabala,što se mo�e dovesti u vezu s uzrokom odumiranjastabala.Analiza drvnih masa odumrlih stabala hrastalu�njaka na dva mikrostaništa prikazana je nagrafikonima 2 i 3. Utvrðena je maksimalna kolièina

2. The research area

3. Method of work

4. Results

The research was carried out in lowland forestecosystems of common oak in the Opeka MU of theEducational Experimental Forest Facility (EEFF),Lipovljani, of the Forestry Faculty, Zagreb University.The Opeka MU has an area of 547 ha, and is fairlyrepresentative of the lowland forests with commonoak, European hornbeam, narrow-leaved ash andblack alder as the main species of forest tree. This isan area that lies about 5 km south of the Zagreb-Belgrade motorway, close to the villages of KraljevnaVelika and Lipovljani, and about 15 km south east ofKutina. The hydrological conditions of these forestecosystems are very dependent on the Sava River,which is about 5 km south of the facility and its leftbank tributaries (Trebe� and Veliki Strug). The reliefis typically lowland, gently rolling, with marked micro-elevations and micro-depressions, the height abovesea level being 93-99 m. The stands are mixed, withcommon oak accounting for 60-70% of the mix,narrow-leaved ash for 15-25%, and the restconsisting of other kinds of tree. The age of thestand is from 105 to 150 years.

According to the reception of dead trees of commonoak and narrow-leaved ash in Opeak MU, data wereprocessed about the total wood mass of dead treesof common oak and narrow-leaved ash for theperiod 1986-2003. Since the intensity of the diebackof trees is very dependent on habitat factors,sections of two different micro-habitats in which thedieback of trees of approximately equal areas werepicked out from the books. Analyses of the woodmass of dead trees per unit of area (ha) were made,and then the values of the total wood mass of deadtrees per micro-habitat and age class werecompared.

The wood mass of dead common oak and narrow-leaved ash trees in Opeka MU of the EEFF Lipovljanivaried considerably in the 1986-2003 period.Graph 1 shows two maximum tree mortalities, ofwhich the first is characterised by an importantmortality of common oak and narrow-leaved ashtrees, while in the second maximum it is the mortalityof common oak that is dominant. Graph 5 shows thechanges in the dynamics of the underground waterfor the years in which the maximum mortality of treesoccurred, which can be causally connected with thetree mortality.Analysis of the wood mass of the dead common oaktrees at the two micro-habitats is shown in Graph 2and Graph 3. A maximum amount of dead treeswere determined in 1989 at a micro-depression,


61



odumrlih stabala 1989. godine na mikroudubini(niza), dok je u posljednih nekoliko godina veæakolièina odumrlih stabala po ha utvrðena namikrouzvisini (greda). Slièan i još naglašeniji trendveæeg odumiranja stabala hrasta lu�njaka namikrouzvisini utvrðen je kod apsolutnih vrijednosti(grafikon 3).Prema grafikonu 4 ne postoje znaèajne razlike udrvnoj masi odumrlih stabala po ha s obzirom narazlièitu dob stabala. U posljednjih nekoliko godinauoèava se veæi intenzitet odumiranja stabala V.dobnog razreda na mikrouzvisini nego onih VI.dobnog razreda u istim uvjetima i stabala namikroudubini.Intenziteti odumiranja stabala hrasta lu�njaka su biliveæi u posljednjem desetogodišnjem razdoblju namikrouzvisini nego na mikroudubini i kretali su se od4 do 14% u odnosu na drvnu masu hrasta lu�njaka(tablica 1).

while in the more recent years, a greater amount ofdead trees per hectare has been established on themicro-elevations. A similar though even morepronounced trend towards a greater common oakmortality on the micro-elevations has beenestablished in the case of the absolute values(Graph 3).According to Graph 4 there are no importantdifferences in the wood mass of dead trees per ha ascompared with the various ages of the trees. In thelast few years a greater intensity of mortality can befound in trees of the 5th cohort on the micro-elevation as compared with trees of the 6th age classin the same conditions and trees in the micro-depression.The intensities of mortality of common oak treeswere greater in the last ten year period on the micro-elevation than in the micro-depression, and rangedin the area of 4-14% as compared with the commonoak wood mass (Table 1).

Grafikon 1 Drvna masa odumrlih stabala hrasta lu�njaka i poljskogjasena u g. j. Opeke za razdoblje 1986.-2003.

Grafikon 2 Drvna masa odumrlih stabala hrasta lu�njaka po ha u g. j.Opeke na dva razlièita mikrostaništa





Grafikon 3 Ukupna drvna masa odumrlih stabala hrasta lu�njaka u g. j.Opeke na dva razlièita mikrostaništa

Grafikon 4 Drvna masa odumrlih stabala hrasta lu�njaka po ha u g. j.Opeke po dobnim razredima i mikroreljefu

Grafikon 5 Minimalne razine podzemnih voda u pjezometru dubine 4 m u g. j.Opeke na dva razlièita mikrostaništa


63



5. Rasprava

Stabilnost nizinskih šumskih ekosustava ovisi obrojnim èimbenicima od kojih su najjaèi hidrološkiodnosi, biotski i klimatski utjecaji. Prema procjenamaošteæenosti krošanja u Hrvatskoj, hrast lu�njak jenajošteæenija listopadna vrsta drveæa (Seletkoviæ iPotoèiæ, 2004.). To je va�an pokazatelj poremetnjefiziološke stabilnosti stabala. Meðutim, propadanjestabala je pokazatelj poremeæaja stabilnostiekosustava. Dosadašnja istra�ivanja su potvrdilakompleksnost ekoloških odnosa u nizinskimšumskim ekosustavima. Propadanjem stabalahrasta lu�njaka nastaju veliki gospodarski gubici ineprocjenjiva ekološka šteta (Prpiæ, 2003.).Posljedice su smanjenje proizvodnosti i kakvoæedrvne tvari, ote�ana prirodna obnova i, èesto,degradacija staništa. Intenzivno propadanje stabalautjeèe na zakorovljenje, a mjestimièno na pojavubarskih uvjeta (Aniæ et al. 2002). Katastrofalna

5. Discussion

The stability of lowland forest ecosystems dependson numerous factors, of which the hydrologicalrelations, biotic and climate factors are the mostimportant. According to canopy cover damageestimates the common oak is the most damageddeciduous species of tree in Croatia (Seletkoviæ andPotoèiæ, 2004). This is an important indicator of thedisturbance of the physiological stability of the trees.However, dieback of trees is an indicator ofecosystem equilibrium disturbance. Investigationsto date have confirmed the complexity of ecologicalrelations in the lowland forest ecosystems. Whenoak trees undergo dieback, great economic lossesand inestimable ecological damage are caused(Prpiæ, 2003). The consequence is the reduction ofthe productivity and quality of wood matter, greaterdifficulty in natural regeneration, and frequenthabitat degradation. Intensive dieback of treesaffects occurrence of weeds and in some places theappearance of marshy conditions (Aniæ et al. 2002).





The catastrophic diebacks of common oak trees inthe forest of �utica in the Novoselec Forest Unitwere recorded only in the micro-depressions, whileon the micro-elevations the dieback of the trees wasoccasional. A similar condition of stability andresistance were shown by the forest ecosystems onthe micro-elevations in other areas where thedieback of oak trees was confirmed, as in Kalje,Turopoljski lug and Pokupski bazen (Barièeviæ,1999). The dieback of trees in Opeka MU, EEFFLipovljani in the period from 1998-2003 showed agreater intensity on the micro-elevation, while in theearlier period there were no important differences inintensity of dieback of trees in the different micro-habitats. These differences were greater withreference to absolute values (300-700 cubic metreson the micro-elevation as against 200-450 cubicmetres in the micro-depression), while thedifferences in the quantity of dead trees per unit ofarea were smaller. These results suggest theconclusion that climatic conditions, particularlyclimatic extremes (droughts) are one of thepredisposition factors for the appearance ofcommon oak mortality. An important factor too isthe underground water, the dynamics of which inextreme years was disturbed as compared with thenormal situation in earlier years. We can link thiswith the trend to the decline in radial increment ofcommon oak from the 1980s on, with a marked dropin drought-stricken 1988, which according to Prpiæ etal. (1994) suggests that climatic extremes have amajor role in the process of tree mortality. Theconstruction of weirs and dams on the channels andwatercourses is aimed at slowing the rapid drainageof surface waters from the forests (Starèeviæ, 2000),and is one of the measures for restoring equilibriumto the disturbed habitat conditions in the lowlandforest ecosystems. However, in this case, when theclimate is one of the crucial factors for the stability ofthe forest ecosystems of common oak it will benecessary to enhance the management of the forestecosystems in order to reduce the economic andecological damage. This paper has already statedthe greater mortality of trees of the 5th cohort ascompared with the 6th cohort. This says still moreabout the disturbance of the stability of the commonoak forest ecosystems, which luckily have nocatastrophic consequences as yet, which did occurin the past in some areas.

1. Intensity of dieback does not depend on standage.

2. With reference to the microhabitat, the greatestintensity of dieback was established in themicro-depression in 1989, while on the micro-elevation a greater intensity of common oak tree

6. Conclusion

propadanja stabala hrasta lu�njaka u šumi �uticašumarije Novoselec zabilje�ena su iskljuèivo unizama, dok je na gredama propadanje stabala bilomjestimièno. Slièno stanje stabilnosti i otpornostipokazali su šumski ekosustavi na gredi i u drugimpodruèjima gdje je utvrðeno propadanje stabalahrasta lu�njaka, kao što je Kalje, Turopoljski lug iPokupski bazen (Barièeviæ, 1999.). Propadanjestabala u g. j. Opeke NPŠO Lipovljani u razdoblju1998. - 2003. pokazuje veæi intenzitet namikrouzvisini, dok u prijašnjem razdoblju nije biloveæih razlika u intenzitetu odumiranja stabala urazlièitim mikrostaništima. Te razlike su bile veæe uodnosu na apsolutne vrijednosti (300 - 700 m nagredi u odnosu na 200 - 450 m u nizi), dok su razlikeu kolièini odumrlih stabala po jedinici površine bilemanje. Ovi rezultati upuæuju na zakljuèak da suklimatske prilike, posebno klimatski ekscesi (suša),jedan od predisponirajuæih èimbenika za pojavuodumiranja stabala hrasta lu�njaka. Va�an jeèimbenik i podzemna voda èija je dinamika u timekstremnim godinama bila poremeæena u odnosu nanormalno stanje prijašnjih godina. To mo�emodovesti u vezu s trendom opadanja radijalnogprirasta hrasta lu�njaka od osamdesetih godinaprošlog stoljeæa, s izra�enim padom u sušnoj 1988.godini, što prema Prpiæu et al. (1994.) upuæuje nadominantnost klimatskih ekscesa u procesuodumiranja stabala. Izgradnjom pregrada i brana nakanalima i vodotocima nastoji se usporiti brzoodvoðenje površinskih voda iz šuma (Starèeviæ,2000.), što je jedna od mjera uravnote�enjaporemeæenih stanišnih uvjeta u nizinskim šumskimekosustavima. Meðutim, u ovom sluèaju kada jeklima jedan od presudnih èimbenika za stabilnostšumskih ekosustava hrasta lu�njaka, bit æe potrebnointenzivirati gospodarenje i upravljanje šumskimekosustavima kako bi se smanjile gospodarske iekološke štete. U radu je takoðer utvrðeno veæeodumiranje stabala V. dobnog razreda od onih VI.dobnog razreda. To još više govori u prilogporemeæaju stabilnosti šumskih ekosustava hrastalu�njaka, koji na sreæu još nema katastrofalneposljedice kakvih je bilo u prošlosti u nekimpodruèjima.

1. Intenziteti propadanja nisu ovisni o starostisastojina.

2. U odnosu na mikrostanište najveæi intenzitetpropadanja utvrðen je u mikroudubini (niza)1989. godine dok je na mikrouzvisini utvrðen veæi

3

3

6. Zakljuèak


65



intenzitet propadanja stabala hrasta lu�njaka uposljednjih nekoliko godina (1998. - 2003.).

3. Za razdoblje 1996. - 2003. intenzitet propadanjastabala hrasta lu�njaka u g. j. Opeke se kretao od8 do 52 m /ha, što odgovara vrijednosti od 1,5 do10% drvne mase sastojine.

4. U nizinskim šumskim ekosustavima utvrðeno jepropadanje stabala gotovo svih vrsta drveæa, štoje pokazatelj poremeæaja stabilnosti šumskogekosustava.

5. Intenzitet propadanja izravno ne ovisi o starosti,strukturi i stanišnim prilikama, nego okompleksnom djelovanju više nepovoljnihèimbenika.

6. Uzroci propadanja stabala se u prvom reduodnose na biotske, sastojinske i stanišnepromjene u šumskim ekosustavima.

7. Promjene u šumskim ekosustavima posljedicasu znatnog antropogenog neposrednog iposrednog utjecaja.

8. Kompleksnost odnosa i funkcija u šumskimekosustav ima zaht i jeva gospodarenjecjelokupnim ekosustavima gdje æe odnosiorganizama (biljke, �ivotinje, mikroorganizmi ièovjek) i stanišnih prilika biti uravnote�eni sobzirom na ciljeve gospodarenja šumskimekosustavom.

3

dieback has been observed in the last few years(1998-2003).

3. For the 1996-2003 period, the intensity ofdieback of common oak trees in the Opeka MUhas ranged from 8 to 52 cubic metres, whichcorresponds to 1.5 to 10% of the wood mass ofthe stand.

4. In lowland forest ecosystems the dieback oftrees of almost all species has been establishedand is an indicator of a disturbance of the stabilityof the forest ecosystem.

5. The intensity of dieback is not directly dependenton the age, structure and habitat-conditions,rather on the complex working of a number ofunfavourable factors.

6. The causes of the dieback in trees are primarilyconnected with biotic, stand-related and habitat-related changes in the forest ecosystems.

7. Changes in the forest ecosystems are theconsequences of important direct and indirectanthropogenic impacts.

8. The complexity of the relations and functions inforest ecosystems requires management ofintegrated ecosystems, where the relations oforganisms (plants, animals, microorganismsand people) and habitat conditions will bebrought into equilibrium with respect to theobjectives of the management of the forestecosystem.

7. Literatura

Androiæ, M., 1975. Prethodni rezultati timskog istra�ivanja uzroka sušenja hrasta u slavonskim šumama. U:Simpozij Sto godina znanstvenog i organiziranog pristupa šumarstvu jugoistoène Slavonije, JAZU Centar zaznanstveni rad Vinkovci, Zagreb, pp. 59-78.

Aniæ, I., M., Oršaniæ, i M., Deteliæ, 2002: Revitalizacija degradiranoga ekosustava nakon sušenja hrasta lu�njakaprimjer šume Kalje. Šum. list, 11-12: 575-587.

Barièeviæ, D., 1999: Ekološko-vegetacijske promjene u šumama hrasta lu�njaka na podruèju g. j. »�utica«. Šum.list 1-2:17-28.

Dekaniæ, I., 1972. Utvrðivanje najpogodnijih vrsta drveæa i metoda obnove opustošenih površina sušenjemhrasta lu�njaka (Quercus robur L.). Šum. list 4-6, 119-127.

Forest Health Monitoring, 1998: Field Methods Guide. USDAForest Service, Washington.

ICP-Forests Manual on Methods and Criteria for Harmonized Sampling, Assessment, Monitoring and Analysisof the Effects of Air Pollution on Forests. Federal Research Centre for Forestry and Forest Products,Hamburg, Germany.

König, J., 1911. Sušenje hrastika. Šumarski list 1-2, 385-422.

Kovaèeviæ, �., 1928. Sušenje hrastova u Posavini sa entomološko-biološkog gledišta. Šumarski list 4, 182-185.

Kozarac, J., 1897. Šumogojstveni i drvotr�ni aforizmi, crpljeni na temelju prodaje posavskih hrastovih šuma uzadnjem desetgodištu 1887-1896. Šumarski list 7.

Matiæ, S., 2000: Oak forests (Quercus sp.) in Croatia. Glas. šum. pokuse, 37:5-13, Zagreb.

Nenadiæ, Ð., 1940. O posljedicama sušenja hrastovih šuma Gradiške imovne opæine. Glasnik za šumskepokuse 7, 1-29.





Prpiæ, B., 1974. Ekološki aspekt sušenja hrastovih sastojina u nizinskim šumama Hrvatske. Šumarski list 7-9, pp.285-290.

Prpiæ, B., 1988: Sušenje hrasta lu�njaka (Quercus robur L.) u Hrvatskoj u svjetlu ekološke konstitucije vrste.Glasnik za šumske pokuse 25, pp. 1-24.

Prpiæ, B., 1996: Propadanje šuma hrasta lu�njaka. U: Klepac, D. (ur.) Hrast lu�njak (Quercus robur L.) uHrvatskoj, HAZU i «Hrvatske šume»; Zagreb, str. 273-298.

Prpiæ, B., 2001: Utjecaj vodotehnièkih zahvata na stabilnost sastojina hrasta lu�njaka (Quercus robur L.) uHrvatskoj u primjeru HE Novo Virje. Šum. list, 7-8: 379-390.

Prpiæ, B., 2003: Utjecaj tehnièkih zahvata u prostoru na nizinske šume. Šum. list, 5-6: 230-235.

Prpiæ, B., Aniæ, I., 2000: The influence of climate and hydro-technical developments in the stability of thepeduncled oak (Quercus robur L.) stands in Croatia. Glas. šum. pokuse, 37:229-239, Zagreb.

Prpiæ, B., Z. Seletkoviæ i M. Ivkov, 1994: Ošteæenost krošanja glavnih vrsta drveæa u Hrvatskoj u odnosu naradijalne priraste. Šum. list, 1-2: 3-10.

Prpiæ, B., Z. Seletkoviæ, i I. Tikviæ, 1997: O utjecaju kanala Dunav-Sava na šumske ekosustave. Šum. list, 11-12:579-592.

Seletkoviæ, I., Potoèiæ, N., 2004: Ošteæenost šuma u Hrvatskoj u razdoblju 1999 - 2003. godine. Šum. list, 3-4:137-148.

Seletkoviæ, Z. I. Tikviæ, 1996: Ošteæenost šumskih ekosustava razlièitih stanišnih prilika u Republici Hrvatskoj.HŠD - Skrb za hrvatske šume od 1846. do 1996., Knjiga 2, str. 81-88, Zagreb.

Seletkoviæ, Z. i Tikviæ, I., 1998: Klimatska i hidrološka funkcija nizinskih šumskih ekosustava, U: Prpiæ, B. (ur),Zbornik radova meðunarodne konferencije Odr�ivo gospodarsko korištenje nizinskih rijeka i zaštita prirode iokoliša, Hrvatsko šumarsko društvo, Zagreb, str. 38-43.

Seletkoviæ, Z., Tikviæ, I., 1996: Ošteæenost šumskih ekosustava razlièitih stanišnih prilika u Republici Hrvatskoj.U: Sever, S. (ur.), Zaštita šuma i pridobivanje drva, Šumarski fakultet Sveuèilište u Zagrebu i Šumarski institutJastrebarsko, str. 81-88.

Starèeviæ, M., 2000: Utjecaj hidromelioracija na šumsku vegetaciju Varoškog luga. Šum. list, 1-2: 15-26.

Starèeviæ, M., 2003: Utjecaj oborinske, poplavne i podzemne vode na razvoj sastojina šumskog kompleksa«Èesma». Šum. list, 11-12:561-578.

Tikviæ, I., 2001: Prirodne ektomikorizne zajednice na hrastu lu�njaku (Quercus robur L.) u Posavini. Disertacija,Šumarski fakultet Sveuèilište u Zagrebu, str. 1-163.

Vajda, Z., 1968. Nauèno istra�ivaèke studije o sušenju hrastika. Šumarski list 2-3, pp. 122-142.

Vukeliæ, J., Rauš, Ð., 1998. Šumarska fitocenologija i šumske zajednice u Hrvatskoj. Sveuèilište u Zagrebu,Šumarski fakultet, Zagreb.

Vukeliæ, J., Tikviæ, I., Seletkoviæ, Z., Barièeviæ, D., 1997: Dieback of Pedunculate Oak from the Ecological-Vegetative Aspect. IUFRO meðunarodna konferencija "Advances in Research in Intermediate Oak Stands",213-222, Freiburg.

Doc. dr. sc. Ivica Tikviæ, prof. dr. sc. Zvonko SeletkoviæŠumarski fakultet

Sveuèilište u Zagrebu,Zavod za Uzgajanje šuma,

Svetošimunska 25, HR-10 000 Zagreb


67



ZAKLJUÈCI SA STRUÈNOGSKUPA - STANJE ŠUMA U PARKUPRIRODE LONJSKO POLJE -GOSPODARENJE I OÈUVANJEKRAJOBRAZNE I BIOLOŠKERAZNOLIKOSTI

Nova Gradiška, 18. o�ujka 2004.

U suradnji Šumarskog fakulteta i Javne ustanovePark prirode Lonjsko polje pripremljen je struèni skup»Stanje šuma u parku prirode Lonjsko polje -gospodarenje i oèuvanje krajobrazne i biološkeraznolikosti«. Skup je odr�an u Novoj Gradiški 18.o�ujka 2004. Na skupu su struènjaci i djelatniciJUPPLP, Šumarskog fakulteta iz Zagreba, Hrvatskihšuma (direkcija i podru�nice Zagreb, Sisak, NovaGradiška) izlagali (9 predavanja) o stanju šuma uParku prirode Lonjsko polje, organizaciji šumarstva,o naèel ima i zakonskim pretpostavkamagospodarenja šumama i o zaštiti biološke ikrajobrazne raznolikosti te oznaèili glavne postojeæeprobleme u šumama s podruèja parka i moguæeputove prema poboljšanju stanja.

Na skupu je zakljuèeno da se osnuje radna skupinaza donošenje zakljuèaka skupa. Izabrani su èlanoviradne skupine kako slijedi:

- Nives Farkaš-Topolnik, dipl. ing. - Park prirodeMedvednica

- mr. sc. Petar Jurjeviæ - Hrvatske šume d.o.o.Zagreb

- mr. sc. Ivica Milkoviæ - Hrvatske šme d.o.o.Zagreb

- dr. sc. Juro Èavloviæ - Šumarski fakultet Zagreb- dr. sc. IgorAniæ - Šumarski fakulet Zagreb- Ivan Štanfar, dipl. ing. - HŠ, Podru�nica Nova

Gradiška- Goran Gugiæ, dipl. ing. - Javna ustanova Park

prirode Lonjsko polje- mr. sc. Darko Kovaèiæ - Javna ustanova Park

prirode Lonjsko polje

1. Šum

aradicionalni naèin uz

Zakljuèci :

ama u PPLP, koje su jedna od najva�nijihsastavnica prirodnih vrijednosti podruèja,gospodari se na t

CONCLUSIONS OF THECONFERENCE - THE CONDITIONOF THE FORESTS IN THELONJSKO POLJE NATURE PARKMANAGEMENT ANDPRESERVATION OF LANDSCAPEAND BIOLOGICAL DIVERSITY

Nova Gradiška March 18 2004

The Forestry Faculty and Lonjsko Polje Nature ParkPublic Institution prepared a conference called theCondition of the Forests in Lonjsko Polje NaturePark the Management and Preservation ofLandscape and Biological Diversity. Theconference was held in Nova Gradiška on March 182004. At the conference, experts and employees ofLonjsko Polje Nature Park, the Forestry FacultyZagreb, Croatian Forests (Main Office and Zagreb,Sisak and Nova Gradiska branches) gave X lecturesconcerning the condition of the forests in LonjskoPolje Nature Park, the organisation of forestry, theprinciples and legal conditions for the managementof forests and the protection of biological andlandscape diversity, as well as marking out the mainexisting problems in the forests of the nature parkand possible ways to improve the situation.

At the forest it was agreed to found a working groupto draw up the Conclusions of the conference. Thefollowing members of the working group wereelected:

- Nives Farkaš-Topolnik dipl.ing. - MedvednicaNature Park

- Petar Jurjeviæ MSc - Hrvatske šume d.o.o.[Croatian Forests Ltd] Zagreb

- Ivica Milkoviæ MSc - Hrvatske šume d.o.o.Zagreb

- Dr Juro Èavloviæ - Forestry Faculty, Zagreb- Dr IgorAniæ - Forestry Faculty, Zagreb- Ivan Štanfar dipl.ing - HŠ, Nova Gradiška

Branch- Goran Gugiæ dipl.ing. - Lonjsko Polje Nature

Park- Darko Kovaèiæ MSc - Lonjsko Polje Nature

Park

1. The forests in Lonjsko Polje Nature Park are oneof the most important constituents of the naturalvalues of the area, managed in a traditional

Conclusions:





podr�avanje doprirodnoga stanja. Povijesneokolnosti, Domovinski rat, i prirodne pretpostavke(teška obnova zbog nepovoljne hidrološkesituacije, štetnika i biljnih bolesti, utjecajaalohtonih vrsta bilja na uspješnost obnove) tedosadašnji naèin planiranja gospodarenjautjecale su na po�eljnu strukturu šuma u parkuprirode.

2. U duhu dosadašnje dobre suradnje šumarskestruke i Uprave Parka prirode treba pronaæirješenja za najva�nije probleme koji se pojavljujuu gospodarenju šumama u parku i zaštiti prirodnei kulturne baštine u njemu. To su sljedeæiproblemi: dovoðenje dobne strukture šuma štobli�e normalnom stanju, smanjenje negativnogutjecaja vodnog re�ima na gospodarenje,posebice obnovu šuma, bolje ureðenje lovstva itradicijskog stoèarenja kako bi se smanjio njihovsadašnji negativni utjecaj na obnovu šuma,rješavanje negativnog utjecaja alohtonih vrstabiljaka (Amorpha fruticosa, Fraxinus americana,Gleditschia triacanthos) na obnovu šuma ioèuvanje biološke i krajobrazne raznolikosti,ponovno širenje nizinskog brijesta (Ulmuslaevis), optimalna primjena mjera gospodarenjašumama u parku, koje potrajno osiguravajunjihovu stabilnost, biološku raznolikost,produktivnost i moguænost obnove, promjene uzakonodavstvu kojim se regulira šumarskadjelatnost i zaštita prirode koje bi dovele dofleksibilnijih propisa, primjerenih iznala�enjurješenja u uvjetima zaštiæenog podruèja tipaparka prirode.

3. Poboljšanje strukture šume, a posebice dobne, uparku predla�e se postiæi radom na tri polja:izradom struène podloge (stanje, moguæi modeliupravljanja/gospodarenja); na zakonodavnojrazini; i izradom modela ciljanog stanja šuma uodnosu na �eljenu bioraznolikost.

4. Potrebno je izraditi preciznu struènu analizudinamike plavljenja retencijskih podruèja, utjecajavodnog re�ima na obnovu i gospodarenješumama (SWOT analiza; Cost/benifit analiza),model moguæih promjena u vegetaciji vezano uzplanove dogradnje sustava obrane od poplavasrednjeg Posavlja s kvantificiranim prikazompromjena u prostornom i vremenskom slijedu.Potrebno je osmisliti sustav uspješna utjecajaJavne ustanove i Hrvatskih šuma i šumarskeznanosti na planiranje i provoðenje dogradnje

manner that supports a quasi-natural state ofaffairs. Historical circumstances, the HomelandWar and natural premises (difficulty ofregeneration because of adverse hydrologicalconditions, pests and plant diseases, the impactof imported species of plants on the success ofregeneration) and the previous manner ofplanning management have affected thestructure of forests in the nature park.

2. In the spirit of the good collaboration to datebetween the forestry profession and themanagement of the Nature Park it is necessary tofind solutions for the most important problems thatoccur in the management of the forests in the parkand in the protection of the natural and culturalheritage within them. The problems are as follows:getting the age structure of the forests as close aspossible to a normal situation, reducing thenegative impacts of the water regime onmanagement, particularly on the regeneration ofthe forests, the optimal arrangement of huntingand traditional animal husbandry so as to reducetheir previous deleterious effect on theregeneration of the forests, the resolution of thedeleterious effect of allochthonous plant species

) on the regeneration of theforests and the preservation of biological andlandscape diversity, the re-dissemination of theEuropean white elm ( ), the optimalapplication of measures for the management of theforests in the park, which will provide for theirlasting stability, biological diversity, productivityand possibility of regeneration, changes inlegislation regulating the forestry industry and theprotection of nature so as to lead to more flexibleregulations, more appropriate solutions inconditions of a protected area of the nature parktype.

3. It is proposed to achieve improvements in thestructure of the forest, particularly of the agestructure, in the park by working in three fields:making a professionally based plan (condition,possible model for management); at the statutorylevel; and elaboration of a model of the targetcondition of the forests with respect to thebiodiversity desired.

4. It is necessary to work out a precise expertanalysis of the dynamics with which thefloodwater retention areas are flooded, the effectof the water regime on the regeneration andmanagement of the forests (SWOT analysis;Cost/Benefit Analysis), a model of possiblechanges in the vegetation related to plans for thefurther development of the flood defence systemof Central Posavina with a depiction of quantifiedchanges in the temporal and spatial sequence. It

Amorpha fruticosa, Fraxinus americana,Gleditschia triacanthos

Ulmus laevis


69



ovog sustava na bazi suradnje s Hrvatskimvodama i drugim korisnicima prostora.

5. Radi smanjenja nepovoljnih utjecaja tradicijskogastoèarenja i uzgoja divljaèi na ionako ote�anuobnovu šuma u plav l jenom podruè ju ,zainteresirane strane trebaju izraditi i provestijasna pravila i uvjete za te djelatnosti. Pri tometreba obnovu šuma staviti kao prioritet.

6. Veliki problemi u obnovi šuma i oèuvanjubioraznolikosti na šumskom i nešumskomzemljištu u parku nastaju radi širenja alohtonihbiljnih vrsta (Amorpha fruticosa, Fraxinusamericana, Gleditschia triacanhtos) . Potrebno je usuradnji šumarske struke i zaštite prirode oformitiistra�ivaèke projekte i konkretne upravljaèkeprojekte koji bi za cilj imali prihvatljivo uklanjanjealohtonih vrsta iz podruèja, sprjeèavanje njihovaširenja i, posebno, smanjenja utjecaja na obnovušuma.

7. Nestankom nizinskoga brijesta narušena jestabilnost i struktura šuma. Predla�e se razvojprograma kojim bi se pokušalo nizinski brijestvratiti u sastav šuma. Program treba imatiistra�ivaèku komponentu, aplikativni dio i programmonitoringa. Treba ga ostvariti u suradnjišumarske struke (Šumarski fakultet, Šumarskiinstitut, Hrvatske šume) i zaštite prirode (JUPPLP,Dr�avni zavod za zaštitu prirode).

8. U gospodarenju šumskim ekosustavom u parkuprirode Lonjsko polje treba primjeniti sve mjerekoje osiguravaju maksimalnu razinu podr�avanja ioèuvanja biološke i krajobrazne raznolikosti,sukladno zakonskim propisima i mjeramaprihvaæenim u Hrvatskoj i EU. Pri tome trebaprimijeniti pravilo da je svaki korisnik odgovoran zaoèuvanje bioraznolikosti, slijediti upute strateškihdokumenata (Strategija šumarstva RH, Strategijaoèuvanja krajobrazne i biološke raznolikosti RH,FSC, EU Habitat and species direktive, EUdirektive o šumama te relevantne propise ogospodarenju šumama.

9. Potrebno je iskoristiti iskustva steèena u odnosugospodarenja šumama i zaštiti prirode u PPLonjsko polje kako bi se utjecalo na strukturu isadr�aj zakonskih rješenja iz podruèja šumarstva izaštite prirode na naèin da se osigura dovoljnafleksibilnost propisa. Ona je prijeko potrebna da bise moglo na terenu i u povoljnom vremenskom

is necessary to devise a system for theapplication of effective influence by the NaturePark, Croatian Forests and forestry science onthe planning and the implementation of the furtherdevelopment of this system pursuant tocooperation with Croatian Water and other usersof the area.

5. For the sake of reducing the adverse impacts oftraditional animal husbandry and the rearing ofgame on the regeneration of the forests, alreadyhard enough, in the flooded area, interestedparties should draw up and execute clear rulesand conditions for the activity. In this, priorityshould be assigned to regeneration of the forests.

6. One great problem in the regeneration of theforests and the preservation of biological diversityin the forest and non-forest ground in the park hasarisen as a result of the expansion ofallochthonous plant species (

).Through collaboration between the forestryprofession and nature conservation, researchprojects and concrete management projectsought to be set up with the aim of finding anacceptable way of ridding the area ofallochthonous species, the prevention of theirspread and in particular the reduction of theirimpact on forest regeneration.

7. The stability and structure of the forests havebeen disturbed with the disappearance of theEuropean white elm. It is proposed that aprogramme should be developed to attempt torestore the elm to the constitution of the forests.The programme should have a researchcomponent, an application part and a monitoringprogramme. It should be put into practice throughcooperation between the forestry profession(Forest Faculty, Forestry Institute, CroatianForests) and nature conservation (Lonjsko PoljeNature Park and the State Institute for NatureConservation).

8. In managing forest ecosystems in Lonjsko PoljeNature Park it is necessary to employ allmeasures that will ensure the maximum level ofsupport for and preservation of biological andlandscape diversity, in line with the regulations ofthe law and measures accepted in Croatia and theEU. In so doing one should apply the rule thatevery user is responsible for the preservation ofbiodiversity, should follow the instructions of thestrategic documents (Republic of Croatia ForestryStrategy, Preservation of Landscape and Bio-Diversity of the Republic of Croatia Strategy, FSC,EU Habitats and Species Directives, EU ForestsDirectives and the relevant regulationsconcerning forest management.

Amorpha fruticosa,Fraxinus americana, Gleditschia triacanthos





razdoblju provesti mjere nu�ne za osiguranjepo�eljenog odnosa gospodarenja šumama ioèuvanja biološke i krajobrazne raznolikosti.

U Zagrebu 2.7.2004.

9. It is necessary to make use of the experienceacquired in the relation between forestmanagement and nature protection in LonjskoPolje NP, in order to affect the structure andcontent of legal approaches from the area offorestry and nature protection in such a way as toensure an adequate flexibility in the regulations.This is essential so as to carry out, in the field, in asuitable period of time, measures that areessential for the achievement of a desirablerelationship or ratio between forest managementand the preservation of biological and landscapediversity.


71



BILTEN PRIRODE PARK PARKA NATURE ......Bilten parka prirode Nature Park Bulletin Lonjsko polje Vol....

Documents

Transcript of BILTEN PRIRODE PARK PARKA NATURE ......Bilten parka prirode Nature Park Bulletin Lonjsko polje Vol....