Fiziološke adaptacije bukve (Fagus sylvatica L.), smrče (Picea abies (L.) Karsten) i jele (Abies alba Mill.) na sezonsko variranje abiotičkih činilaca u četiri zaštićena planinska staništa Republike Srbije

Abstract

Tokom tri vegetacione sezone mereni su fiziološki parametri: fotosinteza, transpiracija, efikasnost iskorištavanja vode (WUE), kao i parametri bioprodukcije na odabranim šumskim populacijama bukve (Fagus sylvatica L.), smrče (Picea abies (L.) Kartsen) i jele (Abies alba Mill.), čija su staništa na različitim nadmorskim visinama sa različitom dostupnošću vode u zemljištu. Određivana je i zavisnost između položaja šumske zajednice na padini planine (nadmorska visina i nagib) i fotosinteze, odnosno bioprodukcije biljaka. Cilj istraživanja je bio da se precizno definiše mogući dalji trend geografskog pomeranja staništa odabranih biljnih vrsta koji je u korelaciji sa morfo-fiziološkim adaptivnim odgovorom biljaka na promenu ekoloških uslova životne sredine. Fotosintetička aktivnost tokom vegetacione sezone bila je stabilna ili se povećavala pri optimalnoj vlažnosti zemljišta. Na lokalitetima Tara i Kopaonik količina atmosferskih padavina nije igrala određujuću ulogu u dinamici fotosintetičke asimilacije CO2. Vlažnost zemljišta je na ovim lokalitetima bila visoka i stabilna zbog dreniranja vode sa okolnih brda. Registrovane razlike u dinamici fotosinteze između ispitivanih vrsta povezane su sa različitim životnim ciklusom listopadnih i četinarskih vrsta i sa različitim fiziološkim adaptacionim strategijama na promene faktora spoljašnje sredine. Na dinamiku fotosintetičke asimilacije CO2 signifikantno utiče prosečna temperatura vazduha pre i tokom merenja, prosečna osmonedeljna količina padavina pre merenja, količina padavina na dan merenja, kao i momentalna vlažnost zemljišta (MVZ). Rezultati istraživanja ukazuju da će dejstvo klimatskih promena biti više izraženo na šumskim populacijama koje se nalaze na vršnim, grebenskim lokalitetima većih nadmorskih visina, ili na padinama planina. Sušni periodi tokom vegetacione sezone, značajan su faktor pomeranja šuma planinskih lokaliteta. Bukove šume su dobro adaptirane na sušu i dobro podnose temperaturni stres, međutim, dugi periodi sa oskudnim padavinama izazivaju smanjenje asimilacije CO2 što ograničava značaj šuma u ublažavanju klimatskih promena.

During three vegetation seasons, physiological parameters, such as photosynthesis, transpiration, water use efficiency (WUE), as well as the parameters of bioproduction of the beech (Fagus sylvatica L.), spruce (Picea abies (L.) Kartsen) and fir (Abies alba Mill.) forest populations have been investigated depending on different altitude mountain. The relationship between the photosynthesis (and bioproduction) of plants and the slope of the mountain is also specified according to ecological parameters (water regime and temperature. The aim of this research is to define physiological status of forest mountain ecosystems in relation to the ecological conditions and predict further trend of geographic shift of the habitats, which is in correlation with the plant morpho-physiological adaptation responses on environmental changes. Photosynthetic activity during vegetation season was stable or increased in optimal level of soil moisture conditions. On the localities of Tara and Kopaonik the quantity of atmospheric precipitation did not play a determining role in the dynamics of photosynthetic assimilation of CO2. On these localities soil moisture was high and stable as a result of water running off from surrounding mountains. Detected differences in the dynamics of photosynthesis of the tested species are result of various lifecycles of deciduous and coniferous trees and various physiological adaptation strategies. The most influential effects on the dynamics of the photosynthesis of the beech, spruce and fir plants during the vegetation season were the following abiotic factors: average air temperature before measuring, temperature on the day of measuring, eight-week amount of average precipitation before measuring, amount of precipitation on the day of measuring and soil humidity. The analysis of the physiological parameters of the beech populations of various mountain altitudes show that even if beech is sensitive to draught it has the physiological potential to keep its vitality by efficient managing water. Effect of climatic changes will be more expressed in forests that can be found on high altitude mountain reefs and peaks. Beech forests tolerate temperature and drought stress, but long periods of poor precipitation cause the decrease of CO2 assimilation which consequently decreases their importance in the global reduction of atmospheric CO2, i.e. limits their role in the moderation of climate change.