Ski-pistes can compensate for the climate change-driven loss of bird communities of avalanche tracks in the Alps

Abstract

As a consequence of both climate and land-use change, open alpine habitats are shrinking. Snow avalanches are a natural disturbance that create habitat mosaics which host unique bird communities, but their frequency and severity will probably be influenced by climate change. Ski-pistes can be considered the artificial counterpart of avalanches, and have been shown to have generally negative effects on alpine fauna. In this study, we compared the bird assemblages of these two open, linear habitats in the Italian Alps, to determine if ski-pistes could compensate for the potential loss of avalanche tracks and open habitats in the future. In the forest and treeline ecotone zones, there was little difference in abundance and diversity between avalanche tracks, ski-pistes and reference points. However, above the treeline, avalanche tracks supported greater bird diversity and were characterized by high vegetation diversity, whereas ski-pistes harboured less-abundant and less-diverse bird assemblages in a homogeneous habitat with high grass cover. Shrub-related species were negatively affected by the vegetation removal involved in the creation of ski-pistes, but occurred in suitable habitats in the avalanche tracks at lower elevations. Although ski-pistes had the most negative impacts in high-elevation assemblages, they were used by some species of alpine and low-elevation grasslands, showing that pistes could provide suitable habitats below the natural treeline, which may be of benefit to threatened grassland birds. New high-elevation ski facilities should be discouraged and the conservation potential of ski-pistes could be improved with sustainable management practices by including some important habitat elements from avalanche tracks such as small trees and shrubs.