Presoja varovalnega učinka gozda pred drobirskimi tokovi ob Savi Bohinjki v Soteski

Varovalni gozdovi imajo pomembno vlogo pri zmanjševanju učinka različnih naravnih nevarnosti. V Sloveniji imamo 10 % varovalnih gozdov, 30 % teh gozdovima zaščitno funkcijo. Preučili smo učinkovitost varovalnih gozdov na severozahodu Slovenije, v Soteski med Bledom in Bohinjem, kjer sta ogroženi državna cesta in železnica. Na podlagi geološke karte in karte podvrženosti drobirskim tokovom smo ugotovili vplivno območje drobirskih tokov. Pri modeliranju njihovega širjenja smo uporabili program TopRunDF. Podatke o gozdu smo zbrali na 47 vzorčnih ploskvah, kjer smo izmerili vsa živa drevesa s prsnim premerom ? 10 cm. Podrobno smo opisali sestoje in jih ovrednotili po metodi NaiS. Ugotovili smo, da ima gozd ključno vlogo pri zaščiti infrastrukturnih objektov. Za trajno zaščitno vlogo v enomernih sestojih je potrebno gojenje mozaično raznomernega gozda. V sestojih, kjer gozdnogojitveni ukrepi ne zadostujejo, je potrebno uporabiti tehnične ukrepe. Ker s sestoji niso gospodarili več desetletij so motnje (najpogosteje v obliki vetrolomov) pogoste. Izsledki kažejo, da je potrebno ovrednotenje varovalne in zaščitne funkcije teh gozdov. Priporočamo tudi aktivno nego, kar je v nasprotju z dosedanjo prakso negospodarjenja teh gozdov.Protection forests have an important role of mitigating the influence of various natural hazards. Only 10% of all forests in Slovenia have an indirect protection function, while 30% of them perform a direct protection role. Studyof protection efficiency of beech dominated forests in the Soteska gorge in NW Slovenia, where a main state road and railway are endangered was done. We assessed the starting impacts of the debris-flow natural hazard based on a small-scale geological survey of the terrain characteristics and local debris flow susceptibillity map. For determination of the run-out zones we used the TopRunDF model. Forest structure data was obtained from 47 sample plots where all trees with DBH ? 10 cm were measured. A detailed description and delineation of forest stands was performed. Results showed that the forests stands play a crucial role in protection of infrastructural objects. For long-term protection efficiency, spatially-explicit regeneration patches are needed in uniform forest stands. In areas where silvicultural measures could not provide sufficient protection, technical measures are needed. Since these forests have not been managed for several decades, natural disturbances are frequent. Research findings suggest that assessment and management of these beech dominated protection forests is necessary, contrary to the current practice of non-management in protection forests in Slovenia