Success of planted and natural regeneration following severe disturbance in spruce plantations

V raziskovalni nalogi smo želeli ugotoviti, kakšna je uspešnost umetne in naravne obnove na saniranih gozdnih površinah v okolici Logatca. Pri tem smo ugotavljali, če obstajajo razlike v obnovi na površinah, ki so jih pred ujmo pokrivali čisti smrekovi drogovnjaki in debeljaki. Raziskavo smo opravljali na 10 raziskovalnih ploskvah na površinah, ki so jih prej pokrivali drogovnjaki in 10 ploskvah na površinah, ki so jih prej pokrivali debeljaki. Dimenzije ploskve so bile 10 x 10 m. Pri meritvah smo ugotovili bujno zeliščno plast, katera ovira pomlajevanje saniranih površin. Število vsega mladja je bilo na bivših drogovnjakov in debeljakov praktično enako in je znašalo 2975 osebkov/ha. Pri tem smo na vseh površinah zabeležili dokaj neenakomerno razporejeno mladje. Umetna obnova ni bila uspešna, saj smo zabeležili velik delež posušenih bukev. Nepoškodovanega naravnega mladja je bilo na površinah, ki so jih prej pokrivali debeljaki za 14,8 % manj, sajenega nepoškodovanega mladja pa za 10 % več kot na površinah, ki so jih prej pokrivali drogovnjaki. Prirastki dominantnega mladja so bili pri najštevilčnejših vrstah smreka, bukev in jerebika večji na površinah, ki so jih prej pokrivali drogovnjaki.The goal of this thesis research was to determine the success rate of planted and natural regeneration on forest areas around Logatec following severe damage from a combination of ice storm, bark beetle, and salvage logging. In particular, we focused on forest sites that were comprised of pure spruce prior to these disturbances. We placed 10 research plots inside disturbance patches that were previously dominated by pole stage spruce forest and 10 plots in patches previously covered with mature spruce forest. The plot size was 10x10m. On all plots we found an abundant herb layer, which interferes with the regeneration on these sites. The total densities of regeneration in pole stage and mature forest were virtually the same, at around 2975 individuals/ha. The spatial distribution of regenerated areas was uneven. The success of artificial restoration was very poor, due to high mortality of planted beech. There was 14,8 % less undamaged natural seedlings and 10 % more undamaged planted seedlings inside pole stage stands compared to mature forest. Height growth of seedlings was larger in the pole stage stands