The Effect of Ski-Pistes on Birds and Mammals

The focus of this chapter is on the effect of ski-pistes on birds and small mammals. We present the results of previous research carried out in the north-western Italian Alps both below and above the tree line. Data from other mountain areas are also incorporated. Ski-pistes below the tree line produce a negative edge effect: forest plots at their edges have lower bird diversity and species richness than those far from edges; conversely, species richness is enhanced when the forest grades into a pasture (positive edge effect). Ski-pistes above the tree line are characterized by low bird species richness and diversity. Moreover, plots adjacent to ski-pistes support a significantly lower bird abundance than plots far from ski-pistes, suggesting these ski-pistes, besides exerting a direct negative effect upon their avifauna, may also exert an indirect, detrimental effect on the number of individuals utilizing nearby areas. Small forest mammals clearly avoid ski-pistes, but open habitat species are able to colonize them. The effects of other skidevelopments (i.e. roads, buildings, car parks, lifts etc.) on ski-resorts are also discussed by considering research on the alpine chough in Italy, the elk in the USA and the mountain pygmy possum in Australia. As a conclusion, considering both the impact of ski-pistes on vertebrates and invertebrates, we urge a new, environmentally friendly way of constructing ski-pistes, such as only removing rocks and/or levelling the roughest ground surfaces (to preserve as much soil and natural vegetation as possible). The creation of a gradual transition from forest to ski-run, the retention of tree islands, and the incorporation of woody debris may be other useful interventions.

Keywords: Alpine and sub-alpine belts, birds, diversity, Italian Alps, negative edge effect, ski-developments, ski-pistes, small mammals.