Einfluss der Naturprozesse, waldbaulicher Massnahmen und Schutzmassnahmen auf die Erhaltung der Eibe im Naturreservat Pavelcovo, Slowakei | The effect of natural processes, silvicultural and protective measures on the conservation of common yew in the Nature Reserve Pavelcovo, Slovakia

Abstract

The study analysed a 15-years experiment focusing on the effect of silvicultural treatment (increment thinning) and red deer browsing on the structure and regeneration processes of common yew (Taxus baccata L.) on a series of four permanent experimental plots in the Nature Reserve Pavelcovo. The reserve Pavelcovo is an age-differentiated natural forest with a typical two-layer structure. The fragmented upper layer is formed of common beech, silver fir, sycamore, Norway maple,Wych elm, common ash and European larch. The lower layer,which is relatively continuous, is formed primarily of common yew. Concerning forest typology, a major part of the reserve was classified to Fagetum tiliosum. The analysis of the effect of the thinning from above with negative selection confirmed a significant increment of yew crown diameters. Concerning the damage on yews with DBH over 2 cm by red deer browsing, a positive correlation was observed: with the increasing breastheight diameter, the share of yew trees damaged by barking increased. Red deer at the present counts becomes a serious factor disturbing natural regeneration processes of yew and causing its gradual decline in the forest ecosystems under investigation. The analysis of the efficiency of a thinning from above on the improvement of ecological conditions for seed germination, establishment, survival and growth of yew seedlings showed that in case of a continuous lower layer, the amount of the transmitted light is insufficient and is one of the principal causes of the auto-reduction of this tree species. A better survival of yew would require an intervention into the lower yew layer mainly through a sanitary selection.