Physiological adaptations of beech (Fagus sylvaticaL.), spruce (Picea abies (L.) Karsten) and fir (Abies alba Mill.) on seasonal variation of abiotic factors in four protected mountain habitats in the Republic of Serbia

Abstract

<p>Tokom tri vegetacione sezone mereni su fiziolo&scaron;ki<br />parametri: fotosinteza, transpiracija,&nbsp; efikasnost<br />iskori&scaron;tavanja&nbsp; vode (WUE), kao i parametri<br />bioprodukcije na odabranim &scaron;umskim<br />populacijama bukve&nbsp; (Fagus sylvatica&nbsp; L.), smrče<br />(Picea abies (L.) Kartsen) i jele (Abies alba Mill.),<br />čija su stani&scaron;ta na različitim nadmorskim visinama<br />sa različitom&nbsp; dostupno&scaron;ću vode u zemlji&scaron;tu.<br />Određivana je i zavisnost između položaja &scaron;umske<br />zajednice na padini planine (nadmorska visina i<br />nagib) i fotosinteze, odnosno bioprodukcije<br />biljaka. Cilj istraživanja je bio da se precizno<br />defini&scaron;e mogući dalji trend geografskog<br />pomeranja stani&scaron;ta odabranih biljnih vrsta koji je u<br />korelaciji sa morfo-fiziolo&scaron;kim&nbsp; adaptivnim<br />odgovorom biljaka na promenu ekolo&scaron;kih uslova<br />životne sredine.&nbsp; Fotosintetička aktivnost tokom<br />vegetacione sezone bila je stabilna ili se<br />povećavala pri optimalnoj vlažnosti zemlji&scaron;ta. Na<br />lokalitetima Tara i Kopaonik količina<br />atmosferskih padavina nije igrala određujuću<br />ulogu u dinamici fotosintetičke asimilacije CO₂.<br />Vlažnost zemlji&scaron;ta je na ovim lokalitetima bila<br />visoka i stabilna zbog dreniranja vode sa&nbsp; okolnih<br />brda. Registrovane razlike u dinamici fotosinteze<br />između ispitivanih vrsta povezane su sa različitim<br />životnim ciklusom listopadnih i četinarskih vrsta i<br />sa različitim fiziolo&scaron;kim adaptacionim<br />strategijama na promene faktora spolja&scaron;nje<br />sredine. Na dinamiku fotosintetičke asimilacije<br />CO_2&nbsp;signifikantno utiče prosečna temperatura<br />vazduha pre i tokom merenja, prosečna<br />osmonedeljna količina padavina pre merenja,<br />količina padavina na dan merenja, kao i<br />momentalna vlažnost zemlji&scaron;ta (MVZ). Rezultati<br />istraživanja ukazuju da će dejstvo klimatskih<br />promena biti vi&scaron;e izraženo na &scaron;umskim<br />populacijama koje se nalaze na&nbsp; vr&scaron;nim,<br />grebenskim lokalitetima većih nadmorskih visina,<br />ili na padinama planina. Su&scaron;ni periodi tokom<br />vegetacione sezone, značajan su faktor pomeranja<br />&scaron;uma planinskih lokaliteta. Bukove &scaron;ume su dobro<br />adaptirane na su&scaron;u i dobro podnose temperaturni<br />stres, međutim, dugi periodi sa oskudnim<br />padavinama izazivaju smanjenje asimilacije CO₂<br />&scaron;to ograničava značaj &scaron;uma u ublažavanju<br />klimatskih promena.</p>

<p>During three vegetation seasons,&nbsp; physiological<br />parameters, such as&nbsp; photosynthesis,&nbsp; transpiration,<br />water use efficiency&nbsp; (WUE), as well as the parameters<br />of bioproduction of the&nbsp; beech (Fagus&nbsp; sylvatica&nbsp; L.),<br />spruce (Picea&nbsp; abies&nbsp; (L.) Kartsen) and&nbsp; fir (Abies&nbsp; alba<br />Mill.)&nbsp; forest populations&nbsp; have&nbsp; been investigated<br />depending on different altitude&nbsp; mountain.&nbsp; The<br />relationship between&nbsp; the photosynthesis&nbsp; (and<br />bioproduction)&nbsp; of plants&nbsp; and the&nbsp; slope of the mountain<br />is&nbsp; also specified&nbsp; according to&nbsp; ecological parameters<br />(water&nbsp; regime and temperature.&nbsp; The aim of this<br />research is to define physiological status of forest<br />mountain ecosystems in relation to the ecological<br />conditions and predict further trend of geographic shift<br />of the habitats, which is in&nbsp; correlation with the&nbsp; plant<br />morpho-physiological adaptation responses on<br />environmental&nbsp; changes.&nbsp; Photosynthetic activity<br />during vegetation season was stable or increased&nbsp; in<br />optimal level of soil moisture&nbsp; conditions. On the<br />localities of Tara and Kopaonik the quantity of<br />atmospheric precipitation did not play a determining<br />role in the dynamics of photosynthetic assimilation of<br />CO₂. On these localities soil moisture was high and<br />stable as a result of water running off from<br />surrounding mountains.&nbsp; Detected differences in the<br />dynamics of photosynthesis of the tested species are<br />result of&nbsp; various lifecycles of&nbsp; deciduous and<br />coniferous trees and various physiological adaptation<br />strategies.&nbsp; The most influential effects on the<br />dynamics of the photosynthesis of the&nbsp; beech,&nbsp; spruce<br />and fir plants during the vegetation season were the<br />following abiotic factors: average air temperature<br />before measuring, temperature on the day of<br />measuring,&nbsp; eight-week amount of average<br />precipitation before measuring, amount of<br />precipitation&nbsp; on the day of measuring&nbsp; and&nbsp; soil<br />humidity. The analysis of the physiological parameters<br />of the beech populations of various mountain&nbsp; altitudes<br />show that even if beech is sensitive to draught it has<br />the physiological potential to keep its vitality by<br />efficient managing water.&nbsp; Effect of climatic changes<br />will be more expressed in forests that can be found on<br />high&nbsp; altitude mountain reefs and peaks.&nbsp; Beech forests<br />tolerate temperature&nbsp; and drought&nbsp; stress, but long<br />periods of&nbsp; poor&nbsp; precipitation&nbsp; cause the decrease of<br />CO_2&nbsp;assimilation which consequently decreases their<br />importance in the global reduction of atmospheric<br />CO₂,&nbsp;i.e. limits their role in the&nbsp; moderation&nbsp; of climate<br />change.</p>