Waldbauliche Massnahmen für das Auerhuhn im Sonderwaldreservat Amden: Ein erstes Fazit

Abstract

As a threatened forest grouse species, the capercaillie (Tetrao urogallus) depends on conservation actions in core areas of its Alpine distribution. In this study, we looked at the species' response to silvicultural measures in the special forest reserve of Amden in the canton of St. Gallen, Switzerland. Here, silvicultural measures were taken between 2006 and 2009 in stands that had previously been classified as less or not suitable for capercaillie. In summer 2010, we investigated how stands used by the species differed from unused ones by relating indirect evidence of species presence with forest structural and compositional variables. Evidence of species' habitat use was found in 12 out of 33 surveyed stands. Used stands showed a significantly higher share of bilberry in the ground vegetation layer, a higher proportion of coniferous trees and a lower canopy cover. Furthermore, the proportion of suitable habitat in immediate vicinity of the treated forest stand was higher in used stands. Our results support that habitat restoration by logging is a promising method to improve capercaillie habitat, in particular in fir-spruce forests, where the effectivity of restoration measures was higher compared to fir-beech forests. Hence, managing guidance for the future selection of stands for restoration should be based on habitat suitability of the stand itself and on an appropriate habitat quality of adjacent forest stands.