Abstract ID: 3.11022 | Accepted as Talk | Talk/Oral | TBA | TBA

The complex biophysical template of mountain forest ecosystems generates strong microclimatic gradients that are heterogeneous in time and space. An important concurrent factor – especially in the mountains of the Northern Hemisphere – is represented by the natural forest expansion, favored by the abandonment of traditional agro-pastoral activities. While the effects of canopy cover, forest structure and topography on microclimate have been well studied, the role of post-abandonment forest succession in driving microclimate gradients and buffering effects remains poorly understood.
This study presents a replicable framework to assess these dynamics across two watersheds in the northwestern Italian Alps (Chalamy and Valsavaranche), mainly dominated by conifers and located in two Protected Areas (i.e., Mont Avic Natural Park and Gran Paradiso National Park). Using five historical aerial photographs spanning 1950s–2020s, we identified six successional stages following land abandonment. Transects with varying topographic and vegetation characteristics were established in each watershed, including five plots representing successional stages and one open-area reference plot. Temperature data are being collected within each plot using loggers at multiple heights. Topographic and vegetation attributes were derived from field surveys and Airborne Laser Scanning (ALS) data, while macroclimate data were sourced from a gridded temperature dataset having 100-m spatial and 6-hour temporal resolution.
Preliminary results from the Chalamy watershed reveal microclimate gradients, with increased buffering in later successional stages. However, recent forest expansion limits landscape-scale heterogeneity and microclimatic conditions typical of advanced successional stages. This framework is now being applied to the Valsavarache watershed to assess differences in successional dynamics, influenced by distinct topographic and vegetation features, and to test the methodology and protocol to new conditions.
Our findings highlight the importance of forest successional dynamics in shaping microclimatic conditions in post-abandonment mountain landscapes and demonstrate the replicability of this approach for broader applications in mountainous ecosystems.