Tall Forests Exhibit Heightened Recovery Following Severe Drought: A Remote Sensing Perspective

Context Globally, climate change is increasing the frequency and severity of droughts, significantly impacting forest ecosystems. While previous studies suggest taller forests are more vulnerable during drought, their capacity to recover following drought remains poorly understood, creating uncertainty for forest management. Objectives This study aimed to quantify the role of canopy height in post-drought forest recovery and determine how its importance changes with drought severity at a regional scale. Methods We focused on evergreen broad-leaved forests in southwest China following a severe drought in 2010. We used MODIS EVI to define a forest recovery index, SPEI to classify drought severity, and a LiDAR-derived canopy height map. We then used linear regression and Random Forest models to analyze the relationships and the relative importance of contributing factors. Results Forest recovery was positively correlated with the intensity of the preceding drought. Under severe and extreme drought conditions, forest recovery increased significantly with canopy height (p < 0.001). The relative importance of canopy height as a predictor of recovery also grew with drought intensity, increasing from 18.03% under normal conditions to 20.08% under extreme drought. Conclusions Our findings reveal that while tall forests may suffer more during severe droughts, they exhibit heightened recovery and resilience afterward. This size-dependent recovery dynamic is a critical and previously overlooked factor that should be incorporated into forest dynamic models and climate-adaptive resource management strategies.