The impact of climate change on carbon sequestration, growth and biodiversity of European beech forests in Serbia

Abstract

<p>Prognoze Međuvladinog panela o klimatskim promenama govore da će&nbsp;prostor Jugoistočne Evrope biti&nbsp; pod snažnim uticajem izmenjenih klimatskih&nbsp;uslova u 21. veku. Očekuje se da će leta biti toplija i suvlja sa vi&scaron;e&nbsp;ekstremnih događaja i temperaturama koje mogu u proseku porasti i za čak&nbsp;3,8&deg;C, &scaron;to predstavlja veliki izazov za &scaron;umarstvo. Da bi se odgovorilo na taj&nbsp;izazov neophodno je načiniti i sprovesti adekvatne mere adaptacije, &scaron;to bi&nbsp;značilo prilagođavanje mera gazdovanja &scaron;umama novonastlim ekolo&scaron;kim&nbsp;uslovima. Jedan od značajnih alata u tom prilagođavanju predstavljaju&nbsp;različiti &nbsp;modelarski pristupi. U&nbsp; ovoj disertaciji su upotrebljene&nbsp;najsavremenije metode modeliranja uticaja klimatskih promena na &scaron;ume.&nbsp;Radi se o pionirskom istraživanje koje je prvo takve vrste u regionu. Dva&nbsp;različita metodska pristupa, vezanih za distribuciju, rast, adaptivno i&nbsp;multifunkcionalno gazdovanja bukovim &scaron;umama u Srbiji u klimatskim&nbsp;uslovima 21. veka su uputila na nekoliko najbitnijih rezultata i zaključaka. &nbsp;Izmenjeni klimatski uslovi će imati uticaj na rast i distribuciju bukovih &scaron;uma&nbsp;u 21. veku na osnovu simulacija sa 4C modelom i predikcija pomoću&nbsp;Elenbergovog koeficijenta. Na &nbsp;kraju simuliranog perioda 2001-2030 pomoću&nbsp;4C modela zabeležene su &nbsp;veće zapremine za devet sastojina&nbsp;monodominantnih bukovih &scaron;uma u odnosu na referentni period 1961-1990,&nbsp;dok su zapremine na kraju perioda 2071-2100 po pravilu bile veće ili &nbsp;slične&nbsp;referentnom period. Simulacije u period 2001-2030 su proseku imale najveće&nbsp;godi&scaron;nje priraste i najvi&scaron;e mrtvog drveta, a one u period 1961-1990 &nbsp;najmanje.&nbsp;Najbolje rezultate za vezivanje ugljenika i očuvanje biodiverziteta je pokazao&nbsp;scenario gazdovanja u kojem nije bilo intervencija. Suprotno tome, &nbsp;najvi&scaron;e prinosa drveta je zabeleženo u scenarijima sa najintenzivnijim&nbsp;intervencijama. U adaptivnom multifunkcionalnom gazdovanju bukovim&nbsp;&scaron;umama za scenarija preferencija koje su kreirale tri grupe zainteresovanih&nbsp;strana (Uprava za &scaron;ume, sektor za&scaron;tite prirode i JP &bdquo;Srbija&scaron;ume&ldquo;) pokazalo se&nbsp;da gazdovanje koje podrazumeva če&scaron;će zahvate (pet godina između seča)&nbsp;daje bolje rezultate u odnosu scenarija koji podrazumevaju desetogodi&scaron;nje&nbsp;intervale. Scenariji gazdovanja u kojima su posečena visoka stabla su&nbsp;pokazale bolje rezultate u multifunkcionalnom gazdovanju u odnosu na&nbsp;scenarija gde su sečena niža stabla u istom zapreminskom odnosu za sva&nbsp;<span style="font-size: 12px;">scenarija preferencija zainteresovanih strana. Elenbergov koeficijent je&nbsp;</span><span style="font-size: 12px;">pokazao dobru prediktivnu sposobnost za određivanje donje granice&nbsp;</span><span style="font-size: 12px;">distribucije bukovih &scaron;uma u &nbsp;Srbiji. Do kraja 21. veka okvirno 90% dana&scaron;njih&nbsp;</span><span style="font-size: 12px;">bukovih &scaron;uma će se naći izvan bioklimatske ekolo&scaron;ke ni&scaron;e u kojoj su bili u&nbsp;</span><span style="font-size: 12px;">20. veku, dok će se 50% naći u zoni u kojoj je &nbsp;zabeležen njen masovni&nbsp;</span><span style="font-size: 12px;">mortalitet u Mađarskoj. Izračunate granice EQ su bile ne&scaron;to niže od dobijenih&nbsp;</span><span style="font-size: 12px;">u sličnim studijama u region &scaron;to implicira striktan regionalni i lokalni pristup&nbsp;</span><span style="font-size: 12px;">problem. Poređenje rezultata simulacija sa 4C modelom i EQ za posmatranih&nbsp;</span><span style="font-size: 12px;">devet sastojina je pokazalo različite trendove vezano za rast (distribuciju)&nbsp;</span><span style="font-size: 12px;">bukovih &scaron;uma u Srbiji do kraja 21. veka. 4C model je predvideo pobolj&scaron;anje&nbsp;</span><span style="font-size: 12px;">uslova, dok je EQ predvideo pogor&scaron;anje uslova. Iz tog razloga potrebna su&nbsp;</span><span style="font-size: 12px;">dalja kontinuirana dugoročna istraživanja bukovih &scaron;uma kako bi smo dobili&nbsp;</span><span style="font-size: 12px;">pouzdaniju osnovu za procenu budućeg rasprostranjenja, rasta i planiranja&nbsp;</span><span style="font-size: 12px;">gazdovanja ovim &scaron;umama u budućnosti.</span></p>

<p>Predictions of the Intergovernmental Panel on Climate Change suggest that&nbsp;the region of Southeast Europe will be strongly influenced by the altered&nbsp;climate conditions in 21 century. It is expected that the summers will be&nbsp;hotter and drier with more extreme events and temperatures that can rise on&nbsp;average as much as 3.8 &deg;C. That is a big challenge for forestry. To respond&nbsp;to this challenge it is necessary to make and implement appropriate&nbsp;adaptation measures which would mean adapting forest management&nbsp;practice to changed environmental conditions. Different models are one of&nbsp;the important tools which can be used in this purpose. In this dissertation&nbsp;state-of-the art methods for calculating the impact of climate change on&nbsp;forests have been applied. This is a pioneering work and the first of its kind&nbsp;in the region. Two different methodological approaches, related to the&nbsp;distribution, growth, adaptive and multifunctional management of&nbsp;European beech forests in Serbia has been performed and provided&nbsp;following results and conclusions. Changed climatic conditions will have&nbsp;<br />an impact on the growth and distribution of beech forests in 21st century&nbsp;based on simulations with the 4C model and predictions of Ellenberg&rsquo;s&nbsp;climate quotient (EQ). At the end of the simulated period 2001-2030 higher&nbsp;volumes were recorded for the nine beech stands in comparison to the&nbsp;reference period 1961 to 1990, while the volume at the end of the period&nbsp;2071-2100 were higher or similar to the reference period. Simulations in&nbsp;the period 2001-2030&nbsp; have had the greatest average annual increment and&nbsp;the biggest amount of dead wood. The best results for carbon sequestration&nbsp;and biodiversity were provided by management scenario in which there&nbsp;were no management measures. In contrast, the highest yield&nbsp; of timber is&nbsp;recorded in the scenarios with the most intensive management measures.&nbsp;The adaptive multifunctional &nbsp;management of beech forests including three&nbsp;<span style="font-size: 12px;">scenarios of preferences&rsquo; (Forest Directorate , Nature Protection Sector and&nbsp;</span><span style="font-size: 12px;">Public Enterprise &quot;Srbija&scaron;ume&quot; ) suggested that management measures that&nbsp;</span><span style="font-size: 12px;">involved more frequent interventions (five years between felling) gives</span><span style="font-size: 12px;">better results than scenario which include a ten-year periods. Scenarios in&nbsp;</span><span style="font-size: 12px;">which higher trees are cut provide better results than scenario where the&nbsp;</span><span style="font-size: 12px;">lower trees are cut. EQ showed good predictive capability for determining&nbsp;</span><span style="font-size: 12px;">the lower (xeric) limit of the distribution of beech forests in Serbia. By the&nbsp;</span><span style="font-size: 12px;">end of 21st century, approximately 90 % of today&#39;s beech forests will be&nbsp;</span><span style="font-size: 12px;">found outside the bioclimatic niches in which they were in the 20th century,&nbsp;</span><span style="font-size: 12px;">while the 50 % of them will be in the zone in which their mass mortality is&nbsp;</span><span style="font-size: 12px;">observed in Hungary. Calculated EQ beech threshold distribution for Serbia&nbsp;</span><span style="font-size: 12px;">were slightly lower than in similar studies in the region (Hungary) , which&nbsp;</span><span style="font-size: 12px;">implies strict regional and local approach to the problem. Comparison of&nbsp;</span><span style="font-size: 12px;">simulated results with the 4C model and EQ for nine stands showed </span><span style="font-size: 12px;">different trends related to growth (distribution) of beech forests in Serbia by&nbsp;</span><span style="font-size: 12px;">the end of 21st century. 4C model predicted improvement of environmental </span><span style="font-size: 12px;">conditions, while the EQ predicted their worsening. For this reason,&nbsp;</span><span style="font-size: 12px;">continuing long-term studies of beech forests are needed in order to get a&nbsp;</span><span style="font-size: 12px;">more reliable basis for estimating future distribution, growth and planning&nbsp;</span><span style="font-size: 12px;">of forest management in the future.</span></p>