Shan Rongxu, Feng Ganxin, Lin Yuwei, Ma Zilong
School of Ecology, Shenzhen Campus of Sun Yat-sen University, Guangdong, 518107, China.
Shapotou Desert Research and Experiment Station, Northwest Institute of Eco-environment and Resource Research, Chinese Academy of Sciences, Lanzhou, China.
Nat Commun. 2025 Mar 20;16(1):2745. doi: 10.1038/s41467-025-57984-3.
There is compelling experimental evidence and theoretical predictions that temporal stability of productivity, i.e., the summation of aboveground biomass growth of surviving and recruitment trees, increases with succession. However, the temporal change in productivity stability in natural forests, which may undergo functional diversity loss during canopy transition, remains unclear. Here, we use the forest inventory dataset across the eastern United States to explore how the temporal stability of forest productivity at multi-spatial scales changes with stand age during canopy transition. We find that productivity stability decreases with stand age at the local and metacommunity scales. Specifically, consistent declines in local diversity result in less asynchronous productivity dynamics among species over succession, consequently weakening local stability. Meanwhile, increasing mortality and the transition from conservative to acquisitive species with succession weaken species and local stability. Successional increases in species composition dissimilarity among local communities cause more asynchronous productivity dynamics among local communities. However, the decline in local stability surpasses the rise in asynchronous productivity dynamics among local communities, resulting in lower metacommunity stability in old forests. Our results suggest lower productivity stability in old-growth forests and highlight the urgency of protecting diversity at multiple spatial scales to maintain productivity stability.
有令人信服的实验证据和理论预测表明，生产力的时间稳定性，即存活树木和新招募树木地上生物量增长的总和，会随着演替而增加。然而，天然森林生产力稳定性的时间变化尚不清楚，因为在冠层转变过程中，天然森林可能会经历功能多样性丧失。在这里，我们使用美国东部的森林清查数据集，探讨在冠层转变过程中，多空间尺度上森林生产力的时间稳定性如何随林分年龄变化。我们发现，在局部和集合群落尺度上，生产力稳定性随林分年龄的增加而降低。具体来说，局部多样性的持续下降导致物种间生产力动态在演替过程中缺乏同步性，从而削弱了局部稳定性。同时，死亡率的增加以及随着演替从保守型物种向 acquisitive 物种的转变削弱了物种和局部稳定性。局部群落间物种组成差异的演替增加导致局部群落间生产力动态更加不同步。然而，局部稳定性的下降超过了局部群落间生产力动态不同步性的增加，导致老龄森林中集合群落稳定性较低。我们的研究结果表明老龄森林的生产力稳定性较低，并强调了在多个空间尺度上保护多样性以维持生产力稳定性的紧迫性。
