Biodiversity Matters More in Wetter Forests

The University of Michigan has led a comprehensive study, encompassing 15 tree diversity experiments across the globe, revealing a nuanced understanding of biodiversity's impact on ecosystems. Research shows that biodiversity is crucial in every forest, but its effects are significantly more pronounced in wetter climates, providing valuable insights for land managers and conservationists. The study, published in Nature Ecology & Evolution, found that trees with more diverse neighbors in wetter climates grow more, while the effect is weaker or nonexistent in drier climates.

Key Takeaways:

• Biodiversity matters more in wetter forests, where it has a more pronounced impact on tree growth and ecosystem functioning.
• In wetter climates, trees with more diverse neighbors grow more, while in drier climates, the effect is weaker or nonexistent.
• The study used a granular approach, examining every individual tree and its neighbors, rather than averaging biodiversity across entire communities.
• The research found that biodiversity's impact in wetter years in wetter climates is negligible, suggesting it is better suited for average conditions rather than extreme years.
• The study, which involved 100,000 trees across 130 species, provides a valuable understanding of biodiversity's role in different environments, with implications for managing and restoring forests.
• The Tree Diversity Network, a global collaboration of researchers, enabled the study by providing access to 34 experimental sites across the world.
• Funding for the study came from various international sources, including the US National Science Foundation, German Research Foundation, and University of Chinese Academy of Sciences.
• Study lead author Liting Zheng highlighted the importance of establishing and maintaining high neighborhood diversity in forest management, especially for maximizing biodiversity's potential as a nature-based climate solution in wetter regions.
• Peter Reich, senior researcher and professor at the University of Michigan, stressed that the "wetter" designation includes more than just tropical rainforests and includes very wet climates, such as Michigan's forests.

Statistics:

• 100,000 trees belonging to nearly 130 species were examined in the study.
• The study used 15 tree diversity experiments across the globe, spanning a range of climates.
• The research was funded by international sources, including the US National Science Foundation, German Research Foundation, Sao Paulo Research Foundation, and University of Chinese Academy of Sciences.
• The study was published in Nature Ecology & Evolution with a DOI of 10.1038/s41559-025-02805-5.
• The Tree Diversity Network is the world's largest network of tree diversity experiments, with 34 different sites.

Sources:

• Study: Neighbourhood diversity increases tree growth in experimental forests more in wetter climates but not in wetter years (DOI: 10.1038/s41559-025-02805-5)
• News article: Biodiversity Matters in Every Forest, but Even More in Wetter Ones
• University of Michigan press release: Biodiversity Matters in Every Forest, but Even More in Wetter Ones
• Tree Diversity Network website: [no URL provided in the original text]
• University of Michigan's Institute for Global Change Biology website: [no URL provided in the original text]