STATICKÁ STABILITA SMREČÍN VYCHOVÁVANÝCH METÓDOU CIEĽOVÝCH STROMOV.

Norway spruce (Picea abies L. Karst) is economically very important tree species. On the other hand, mainly due to climate change, spruce is considered to be problematic and unpromising in many regions. Spruces are endangered by a wide variety of harmful agents, including abiotic, mechanically acting agents (snow, rime and especially wind). In this paper, knowledge focused on possibilities of increasing the static stability (resistance to wind) of spruce stands is synthesized. It deals mainly with their tending based on target trees method approaches. Following the graphicons of static stability of spruce stands, results from verification of resistance of stands raised by this method are presented. The slenderness ratio (tree height to stem diameter ratio) and the crown proportion (crown length to tree height ratio) of the target trees were used as indicators for the static stability of the spruce stands. Data from long-term research activities on permanent plots located in a substantial part of the territory with natural occurrence of spruce in Slovakia were used as testing material. Research results indicate that trees with a favourable degree of static stability can be achieved in spruce forests by implementing the method of target trees. Finally, we propose measures how to apply the theoretical results of this work in forestry practice, namely in the planning and forest silviculture operations. [ABSTRACT FROM AUTHOR]