586 KB56 KB193820262016Vilhar, Uršaštevilka:1letnik:74str. 28-45ISSN:0017-2723COBISSID:4298662URN:URN:NBN:SI:doc-31NYKF0ZslZveza društev inženirjev in tehnikov gozdarstva in lesarstva SlovenijeGozdarski vestnikmešanost drevesnih vrstodtok po deblupremenaprepuščene padavinesmrekove monokultureSestojne padavine v mešanih sestojih smreke in bukve na Pohorju| Throughfall in mixed beech-spruce forests in the Pohorje mountains|Net precipitation in forests consists of water (throughfall), reaching the ground through canopy gaps or dripping from the foliage or branches and stemflow. In this study, the effect of tree species conversion in spruce monocultures into mixed deciduous-coniferous forests in Pohorje on net precipitation was investigated. Such changes might affect hydrological processes on the general catchment scale, since higher share of deciduous trees in mixed forests contributes to higher throughfall and stemflow and lower canopy interception. Four Norway spruce forests and four mixed spruce-beech forests in the Upper Oplotnica River catchment on Pohorje with varying share of spruce and beech in the growing stock were investigated. Net precipitation was estimated for each forest from measured or estimated throughfall and stemflow for the period from 2008 to 2014. Annual throughfall in selected forests ranged from 76 % to 82 % of the bulk precipitation. Annual stemflow was present only in two forests, ranging from 3 % to 12 % of the bulk precipitation, respectively. Annual net precipitation averaged to 92 % of the bulk precipitation, ranging from 99 % for the dormancy to 89 % for the growing season. Therefore, annual net precipitation was decreasing with increasing share of spruce in the growing stock, indicating higher canopy interception in mixed forests with prevailing spruce. In addition, the average net precipitation during the growing season was 10 % lower than during the dormancy, indicating higher interception during the growing season. Net precipitation is important indicator of hydrologic functions of forests (e.g. forest ecosystem services, related to water provisioning and regulating), since it is indicating the canopy interception capacity. The results of this study could contribute to the implementation of hydrology-oriented sylvicultural measures on a catchment scale, aiming at improved hydrological functions of forestsSestojne padavine v gozdu so vsota prepuščenih padavin, ki so bodisi padle v vrzelih krošenj, v obliki kapljic odtekle z njih ali po deblih odtekle do gozdnih tal (odtok po deblu). V prispevku obravnavamo, kako v antropogenih smrekovih sestojih na Pohorju spremembe v mešanosti drevesnih vrst vplivajo na sestojne padavine. Take spremembe lahko vplivajo na hidrologijo celotnega porečja, saj večji delež listavcev v mešanih gozdovih prispeva k večjemu deležu prepuščenih padavin in odtoka po deblu ter manjšemu prestrezanju padavin v krošnjah dreves. Raziskave so potekale v štirih sestojih smreke in štirih mešanih sestojih z različnim deležem smreke in bukve v zgornjem porečju Oplotnice na Pohorju. V letih od 2008 do 2014 smo sestojne padavine za posamezne ploskve ocenili na podlagi merjenih in ocenjenih prepuščenih padavin in odtoka po deblu. Letne prepuščene padavine na ploskvah so znašale od 76 % do 82 % padavin na prostem. Letni odtok po deblu je bil zaznan le na dveh ploskvah, in sicer 3 % in 12 % padavin na prostem. Letne sestojne padavine na ploskvah so v povprečju znašale 92 % padavin na prostem, od tega 99 % v obdobju mirovanja vegetacije in 89 % v vegetacijskem obdobju. Ugotavljamo, da se z večanjem deleža smreke v lesni zalogi zmanjšujejo letne sestojne padavine. Hkrati so sestojne padavine v vegetacijskem obdobju v povprečju 10 % manjše kot v obdobju mirovanja vegetacije, kar kaže na večje prestrezanje padavin v krošnjah mešanih sestojev v času olistanja.Sestojne padavine so pomemben kazalnik za hidrološko funkcijo gozdov, saj odražajo skladiščno zmogljivost krošenj za prestrezanje padavin. Rezultati raziskave lahko pomembno prispevajo k oblikovanju usmerjenih gozdnogojitvenih ukrepov na ravni gozdnatih porečij z namenom izboljšanja hidrološke funkcije gozdovTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaZveza gozdarskih društev Slovenije