Faculty of Natural Resources Management, Lakehead University, Thunder Bay, ON P7B 5E1, Canada.
Institute for Global Change Biology, and School for Environment and Sustainability, University of Michigan, Ann Arbor, MI 48104.
Proc Natl Acad Sci U S A. 2024 Dec 3;121(49):e2405108121. doi: 10.1073/pnas.2405108121. Epub 2024 Nov 25.
The temporal stability of forest productivity is a key ecosystem function and an essential service to humanity. Plot-scale tree diversity experiments with observations over 10 to 11 y indicate that tree diversity increases stability under various environmental changes. However, it remains unknown whether these small-scale experimental findings are relevant to the longer-term stability of natural forests. Using 7,500 natural forest plots across much of Canada, monitored over three to four decades on average, we provide strong evidence that higher temporal stability (defined as the mean productivity divided by its SD over time) is consistently associated with greater tree functional, phylogenetic, and taxonomic diversity across all lengths of observations. Specifically, increasing functional diversity from its minimum to maximum values increases stability, mean productivity, and the temporal SD of productivity by 14%, 36%, and 28%, respectively. Our results highlight that the promotion of functionally, phylogenetically, and/or taxonomically diverse forests could enhance the long-term productivity and stability of natural forests.
森林生产力的时间稳定性是一项关键的生态系统功能，也是人类的一项基本服务。具有 10 到 11 年观测期的斑块尺度树木多样性实验表明，在各种环境变化下，树木多样性会增加稳定性。然而，这些小规模实验结果是否与天然林的长期稳定性有关仍然未知。本研究利用加拿大各地的 7500 个天然林斑块，平均监测时间为三到四十年，提供了强有力的证据表明，更高的时间稳定性（定义为随时间变化的平均生产力除以其标准差）与所有观测长度上更大的树木功能、系统发育和分类多样性始终相关。具体而言，从功能多样性的最小值到最大值增加 14%，分别会增加稳定性、平均生产力和生产力时间标准差 36%和 28%。我们的研究结果强调，促进具有功能、系统发育和/或分类多样性的森林可以提高天然林的长期生产力和稳定性。
