Understanding how diversity affects ecosystem stability is crucial for predicting the consequences of continued habitat and biodiversity loss on ecosystem functions and services. Long‐term productivity stability in plant communities is often associated with greater species, phylogenetic or functional diversity, more complex size and age structures, or higher asynchrony in species fluctuations (compensatory dynamics), all potentially increasing community resistance to perturbations. However, the relative importance of these stabilizing pathways is still poorly understood, especially in old‐growth species‐rich forests. Here we explore how compensatory dynamics and multiple facets of diversity underpin temporal stability of wood biomass production over forty years in a Japanese temperate forest, based on more than 45 500 stem increments from 15 species. Whereas the effect of species richness and phylogenetic diversity was small, the old‐growth structural attributes markedly increased community stability via increased asynchrony in the performance of co‐occurring species. Greater standing tree volume, stem density and interspecific variation in growth rates enhanced productivity stability both directly and indirectly via increased asynchrony. This corroborates the predictions of increased compensatory dynamics with increased asymmetric competition for light in a more productive environment. Asymmetric competition in old‐growth patches, between dominant oaks and sub‐canopy shade‐tolerant firs and maples, is a major driver of productivity stability over time via compensatory dynamics. Overall productivity remains relatively constant in old‐growth patches, as abundant firs and maples in the lower canopy layers compensate for biomass losses in canopy oaks caused by aging, wind and snow disturbances. Younger forest patches, composed of fast‐growing, shade‐intolerant species, had a lower stability of productivity, with reduced stem basal area and tree density due to higher understory bamboo coverage preventing tree regeneration and growth. We provide new insights into mechanisms underlying the stability of ecosystem functioning in diverse forest ecosystems, and emphasize the importance of preserving and supporting old‐growth forests and their structural complexity.

中文翻译：

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温带森林中生态系统稳定性的决定因素

了解多样性如何影响生态系统稳定性对于预测持续生境和生物多样性丧失对生态系统功能和服务的影响至关重要。植物群落的长期生产力稳定性通常与更大的物种，系统发育的或功能的多样性，更复杂的大小和年龄结构或物种波动（补偿动态）的非同步性有关，所有这些都可能增加群落对摄动的抵抗力。然而，人们对这些稳定途径的相对重要性仍然知之甚少，尤其是在物种繁多的古老森林中。在这里，我们探讨了补偿性动力学和多样性的多方面如何支撑日本温带森林四十年来木材生物量生产的时间稳定性，基于15种物种超过45 500的茎增量。尽管物种丰富度和系统发育多样性的影响很小，但通过同时存在的物种表现的异步性增加，旧的生长结构属性显着提高了群落稳定性。更大的立木量，茎密度和种间增长率的差异通过增加异步性直接或间接地提高了生产力的稳定性。这证实了在生产效率更高的环境中，随着光的不对称竞争增加，补偿动态增加的预测。占主导地位的橡树与耐候性耐荫的冷杉和枫树之间的旧生长斑块的不对称竞争是通过补偿动力学随时间推移稳定生产的主要动力。在老生长斑块中，整体生产力保持相对稳定，这是由于较低冠层的大量冷杉和枫树可以补偿因老化，风和雪干扰而引起的冠层橡树生物量损失。由快速生长，耐荫的物种组成的较年轻的森林斑块的生产力稳定性较低，由于较高的下层竹材覆盖率阻止了树木的再生和生长，因此茎的基础面积和树木密度降低。我们提供了对各种森林生态系统中生态系统功能稳定的基础机制的新见解，并强调了保护和支持旧林及其结构复杂性的重要性。由快速生长，耐荫的物种组成的较年轻的森林斑块的生产力稳定性较低，由于较高的下层竹材覆盖率阻止了树木的再生和生长，因此茎的基础面积和树木密度降低。我们提供了对各种森林生态系统中生态系统功能稳定的基础机制的新见解，并强调了保护和支持旧林及其结构复杂性的重要性。由快速生长，耐荫的物种组成的较年轻的森林斑块的生产力稳定性较低，由于较高的下层竹材覆盖率阻止了树木的再生和生长，因此茎的基础面积和树木密度降低。我们提供了对各种森林生态系统中生态系统功能稳定的基础机制的新见解，并强调了保护和支持旧林及其结构复杂性的重要性。