Biodiversity and biomass co‐regulate urban forest drought resistance

Severe droughts induced by climate change present substantial challenges to urban forests. While the role that species richness plays in enhancing drought resistance in natural ecosystems has been highlighted in previous studies, its impact within urban forests remains less understood. Leveraging extensive field‐based measurements across 1115 forest patches and 477 tree species in 116 cities in Yunnan Province, China, we found that species richness and forest cover co‐regulate drought resistance in urban settings. However, a consistent and significant positive effect of species richness was observed primarily in warm, cloudy, higher‐income regions during infrequent dry‐season droughts. Urban forests characterized by a higher proportion of non‐native and evergreen species also exhibited greater drought resistance. These results underscore the importance of effective management in urban forests to enhance their resilience against extreme drought.