Climate change signals in avalanche-protective forest ecosystems of the Alps and Carpathian Mountains: Insights from the CROSSEU Project

Mountain regions exhibit pronounced elevation-dependent climate change, with strong implications for snow regimes, cryosphere-related hazards, and ecosystem processes. In avalanche-prone areas, these climate signals directly affect both avalanche release conditions and the effectiveness of forest ecosystems as natural protection. Identifying regional and elevation-dependent climate change signals is therefore essential for understanding future avalanche dynamics and associated ecosystem-mediated risk regulation.This work explores the future climate change signals throughout the 21st century (under RCP4.5 and RCP8.5 scenarios) for understanding the possible shifts in snow avalanche hazard conditions across the Alps and Carpathian Mountains. Using avalanche-relevant climate hazard indices derived from temperature and snow variables, we assess the expected changes across elevation bands. We relate these signals to the spatial distribution of coniferous forests and how they protect against avalanches - a regulating ecosystem service. Results reveal clear elevation-dependent climate signals affecting avalanche-relevant conditions, with marked contrasts between lower and higher elevation zones. In both mountain systems, changes in snow-related indices indicate a shift in avalanche climate hazard conditions, particularly at mid-elevations where warming and altered snow persistence are most pronounced. Spatial analysis highlights that coniferous forests, identified as key providers of regulating ecosystem services, overlap unevenly with zones experiencing the strongest climate signals, implying potential future mismatches between hazard regulation capacity and changing avalanche conditions.Stakeholder-informed assessments indicate that forest-based protection remains a highly prioritised adaptation option, but its long-term effectiveness may be increasingly constrained by climate-driven changes in snow and temperature regimes. Overall, the CROSSEU results demonstrate that elevation-dependent climate change signals are shaping the environmental context in which avalanche-protective forest ecosystems operate. By linking regional climate change signals with ecosystem service provision, this study provides a comparative perspective on how elevation-dependent climate change may influence natural hazard regulation in mountain regions. The CROSSEU findings contribute to improved understanding of climate impacts in high-elevation environments and support climate-resilient adaptation strategies that account for both changing snow regimes and ecosystem dynamics.This research was funded by the "Cross-sectoral Framework for Socio-Economic Resilience to Climate Change and Extreme Events in Europe (CROSSEU)" project, under the European Union’s Horizon Europe Programme (Grant agreement No. 101081377).