Divergent patterns and determinants of resistance and resilience in short and tall forests across global drylands

Abstract Forests play a crucial role in mitigating climate change, and global afforestation initiatives are in full swing, with drylands having great potential for afforestation. However, many dryland afforestation projects lead to short forests with significantly lower canopy height than their typical height. Meanwhile, the potentially increasing probability of drought threatens short forests and their tall counterparts. Yet, it remains largely unclear whether these short forests respond differently to drought compared to tall forests. Here, we used the K-means clustering method to classify global dryland forests into short and tall forests. We found significant differences in drought resistance and resilience between short and tall forests, with tall forests demonstrating higher resistance and short forests having higher resilience. Furthermore, our study indicated that in severe and extreme drought conditions, resistance and resilience of short forests were more likely influenced by climatic factors than tall forests, which were more likely affected by soil factors. These findings suggest that climatic monitoring should be intensified for short forests, and post-drought management should be strengthened for tall forests to enhance their persistence under climate change.