Tree species diversity protects forests from climate extremes, study finds

New research highlights the vital role that tree species diversity plays in safeguarding forests against the growing threat of extreme climate events. Researchers from Peking University in Beijing and Anglia Ruskin University analyzed data from 88,116 forest plots across the United States to examine the impact of compound climate extremes, where events like drought and extreme heat occur simultaneously.

Published in the journal Nature Communications, the study, led by international scientists, found that forests with greater tree species diversity exhibited better resistance and faster recovery after these combined events. While individual climate extremes have been extensively studied, this research underscores the importance of considering the risks posed by simultaneous occurrences of events, which can amplify each other's negative effects.

For example, extreme heat intensifies drought by increasing evapotranspiration, and excessive moisture can lead to waterlogged soil, causing hypoxia and root damage. The analysis revealed that forests with higher biodiversity experienced smaller declines in productivity and more rapid recovery following compound heat and moisture extremes compared to those with lower diversity.

This suggests that biodiversity acts as a form of biological insurance, helping forests maintain stability in an increasingly unpredictable climate. As forests face increasing frequency and intensity of extreme weather events due to climate change, the study's findings suggest that preserving and enhancing tree species diversity can play a crucial role in mitigating the impacts of climate change and maintaining the vital ecosystem services provided by forests.