Drevesni mikrohabitati v bukovih gozdovih jugovzhodne Slovenije

Abstract

An inventory of tree microhabitats was done in two unmanaged forests (Kobile and Ravna gora forest reserves) and one managed beech forest in SE Slovenia. The purpose of this study was to determine the influence of forest management, natural disturbances, and tree characteristics on microhabitat patterns. Forest structure and microhabitats were recorded in systematically placed plots (500 m2 in size) across each area. In total, we inventoried 849 trees on 54 plots and 1833 tree microhabitats. The results showed that forest management had no significant influence on the abundance of microhabitats per tree, but there were differences regarding microhabitat type between managed and unmanaged sites. There were substantially more microhabitats related to standing dead and live habitat trees in unmanaged forest (e.g. woodpecker cavities, insect galleries and bore holes, branch holes, dead branches and fruiting bodies of fungi), whereas in managed forests there were more tree microhabitats related to management (e.g. exposed heartwood, coarse bark, and epiphytic plants). The results also indicate that disturbance, tree diameter, vitality, and species influence the density, diversity, and occurrence of tree microhabitats.V bukovih gozdovih na območju Gorjancev (JV Slovenija) je bil jeseni 2014 opravljen popis drevesnih mikrohabitatov (DM). Skupno 54 ploskev velikosti 500 m2 je bilo sistematično postavljenih na treh raziskovalnih območjih (v pragozdnem rezervatu Ravna gora in gozdnem rezervatu Kobile ter v bližnjem gospodarskem gozdu). Zabeležili smo 1833 drevesnih mikrohabitatov na 849 drevesih. Namen študije je bil ugotoviti, kako gospodarjenje, naravne motnje ter sestojne značilnosti vplivajo na pojav DM. Podatke smo analizirali s programoma Excel in SPSS z neparametričnimi metodami. Ugotovili smo, da način gospodarjenja ne vpliva značilno na številčnost DM na drevo, vpliva pa na vrsto DM. V obeh rezervatih je bilo zabeleženih več DM, povezanih z odmrlimi in starimi drevesi (dupla ptic, izletne odprtine in rovi podlubnikov ter žuželk, vejne votline, večje odmrle veje in trosnjaki gliv), v gospodarskem gozdu pa več DM, povezanih z gospodarjenjem (izpostavljena beljava, razbrazdana skorja in epifiti). Prav tako smo ugotovili, da na gostoto, raznolikost in pojav DM vplivajo tudi naravne motnje, premer in stanje drevesa ter drevesna vrsta