Impact of Ski-Piste Management on Soil Microbial Activity in the Southern Alps, Italy

Ski-piste development supports recreation and local economies, but management practices (slope grading, snowmaking, and infrastructure installation) introduce disturbances that can alter soils, vegetation, and microclimates, raising concerns about impacts on soil biochemical functioning. This study evaluated the impact of ski-piste management on soil microbial activity across medium-sized (MS) and small-sized (SS) ski resorts. Paired piste (P)–control (C) plots were established, and sampling was conducted over two consecutive summers. Comparative analyses of soil enzyme activities and dsDNA-based microbial biomass at both ski resort categories revealed no statistically significant differences between C and P soils across the 2016 and 2017 sampling years (p > 0.05). At MS, minor shifts in many enzyme activities were noted in 2017; none reached statistical significance. Similarly, at SS sites in 2017, moderate reductions in phosphorus-cycling enzymes and glucuronidase (uroni) were observed in P plots, yet differences remained non-significant. In contrast, interannual variation (2016 vs. 2017) was associated with significant differences in microbial biomass and most enzymatic activities (p < 0.05). In addition, P soils consistently exhibited higher pH than C soils, although this shift did not correspond to detectable changes in biochemical functioning. Overall, ski-piste management did not significantly affect soil biochemical functioning under the conditions investigated, whereas interannual variability appeared to be more strongly driven by differences in soil moisture and snow cover. Continued monitoring at broader spatial and temporal scales is essential to assess the long-term ecological consequences of ski resorts in mountain grasslands.