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.
