The role of thermal constraints in post-disturbance forest recovery across the European Alps – a large-scale remote sensing study

• Forest recovery mapped from Landsat-Sentinel-2 data across the European Alps. • High recovery success across Alps but also high spatial variability. • Warming increases recovery success, but effects vary depending on location. • Additional important drivers of recovery success identified. Forest ecosystems in the European Alps are increasingly affected by climate change, with rising temperatures and more frequent climate extremes altering disturbance regimes and shaping post-disturbance recovery. While climate change is expected to constrain recovery in lowlands due to increasing thermal stress, high-elevation ecosystems were historically limited by temperature, with the net effects of warming on post-disturbance recovery remaining uncertain. Using multi-decadal Earth observation data from Landsat and Sentinel-2 (1986–2023), we quantified post-disturbance canopy recovery and assessed the influence of thermal constraints on recovery. Recovery success, defined as the proportion of disturbed forest reaching 80 % of pre-disturbance tree cover within ten years, indicated that 48 % of disturbances recovered according to this metric. Beyond this general pattern, recovery varied systematically with climate and disturbance characteristics. Recovery success peaked at intermediate summer temperatures and declined with increasing disturbance severity, higher pre-disturbance tree cover, and larger post-disturbance bare-ground share. Precipitation exerted only a minor influence. We found strong evidence that warmer-than-average summers, measured as summer temperature anomalies, improved recovery across the Alps, except for localized responses in the south-western region. Our findings suggest that warming relaxes the thermal limitations for tree growth in large parts of the Alps, with warmer summers providing additional thermal energy and longer snow-free periods favouring canopy regrowth. Notably, the south-western Alps deviated from this pattern, showing a negative relationship between summer temperature anomalies and recovery, with warming increasingly threatening recovery. By providing large-scale empirical evidence on how post-disturbance recovery varies across the Alps, this study improves the understanding of interactions between climate change and forest recovery.