FORESTS MANAGED ON CLOSE-TO-NATURE PRINCIPLES ARE MUCH MORE USEFUL THAN VIRGIN FORESTS

Na Skupštini Akademije šumarskih znanosti, održanoj u prosincu 2008. godine, zaključeno je kako bi sa što više šuma u Hrvatskoj trebalo postupati po načelu prirodnoga gospodarenja šumom, iza kojega stoji zagrebačka škola uzgajanja šuma. Tim uzgojnim postupcima podržava se prirodni sastav šume s potrajnim gospodarenjem, visokom kakvoćom drvne sirovine i velikim proizvodnim potencijalom, u kojemu se u procesu fotosinteze vezuje ugljik i ispušta kisik, uz smanjivanje količine CO2 u atmosferi. Budući da je ugljični dioksid jedan od najzastupljenijih stakleničkih plinova, smanjujujći njegovu koncetraciju, šuma ublažava globalnu pojavu zatopljenja. To se danas smatra jednom od najznačajnijih funkcija šume. Prašuma se sastoji od 5 razvojnih faza - pomlađivanja, inicijalne faze, optimalne faze te faze starenja i propadanja, dok se prirodno gospodarena šuma sastoji iz prve tri prašumske faze - pomlađivanja, inicijalne faze i optimalne faze. Za vrijeme njezina trajanja, asimilacija i vezivanje ugljika vrlo su značajni, dok se u prašumskim fazama starenja i raspadanja asimilacija smanjuje i na kraju potpuno prestaje. Kako te dvije faze prašume traju više od polovice njezina života, ona je dugo vremena u smislu vezivanja ugljika neučinkovita, a smanjuju se protiverozijska i hidrološka funkcija. Prašumama danas teži službena zaštita prirode u Hrvatskoj, dok šumarska znanost smatra kako je potrebno izabrane površine najznačajnijih šumskih zajednica pretvoriti u sekundarne prašume zbog daljnjega njihova proučavanja, a u svim šumama primijeniti prirodno gospodarenje. Biološku raznolikost koju prašuma ima u razvojnim fazama starenja i raspadanja u pojavi velikoga broja svojti kukaca i gljiva u mrtvom drvu, postižemo primjenom FSC certifikacije, ostavljajući u šumi dovoljne količine mrtvoga drva. Prof. em. dr. sc. Branimir PrpićAt the Assembly of the Academy of Forestry Sciences held in December 2008 it was concluded that the majority of the forests in Croatia should be managed according to close-to-nature silviculture, an approach staunchly advocated by the Zagreb School of Silviculture. Such an approach encourages the natural composition of a forest accompanied by sustainable management, high quality of wood material and high productive potential. Carbon is sequestered, oxygen is released and CO2 quantities in the atmosphere are reduced in the process of photosynthesis. Since carbon dioxide is one of the most represented greenhouse gasses, a forest mitigates global warming by reducing its concentrations. This is currently considered one of the most important forest functions. A virgin forest consists of five developmental stages: regeneration, the initial stage, the optimal stage and the stage of ageing and decomposition. In contrast, a naturally managed forest consists of the first three stages of a virgin forest: regeneration, the initial stage and the optimal stage. During its lifetime, carbon assimilation and sequestration play a major role, whereas during ageing and decomposition in a virgin forest assimilation decreases and finally stops completely. Since these two stages account for over half of a virgin forest lifetime, this forest is inefficient in the sense of carbon sequestration. Moreover, its anti-erosion and hydrological functions are also reduced. The official policy of nature protection in Croatia advocates the maintenance of virgin forests. In contrast, the forestry science supports the principle of converting selected areas with the most important forest communities into secondary virgin forests for further study, and applying nature-based management in all forests. Biological diversity displayed by a virgin forest in the developmental stages of ageing and decomposition is reflected in a large number of insect and fungi species in dead wood. This is achieved by leaving sufficient quantities of dead wood in a forest according to the FSC certification. Professor Emeritus Branimir Prpić, Ph