Despite decades of progress, much remains unknown about successional trajectories of carbon (C) cycling in north temperate forests. Drivers and mechanisms of these changes, including the role of different types of disturbances, are particularly elusive. To address this gap, we synthesized decades of data from experimental chronosequences and long‐term monitoring at a well‐studied, regionally representative field site in northern Michigan, USA. Our study provides a comprehensive assessment of changes in above‐ and belowground ecosystem components over two centuries of succession, links temporal dynamics in C pools and fluxes with underlying drivers, and offers several conceptual insights to the field of forest ecology. Our first advance shows how temporal dynamics in some ecosystem components are consistent across severe disturbances that reset succession and partial disturbances that slightly modify it: both of these disturbance types increase soil N availability, alter fungal community composition, and alter growth and competitive interactions between short‐lived pioneer and longer‐lived tree taxa. These changes in turn affect soil C stocks, respiratory emissions, and other belowground processes. Second, we show that some other ecosystem components have effects on C cycling that are not consistent over the course of succession. For example, canopy structure does not influence C uptake early in succession but becomes important as stands develop, and the importance of individual structural properties changes over the course of two centuries of stand development. Third, we show that in recent decades, climate change is masking or overriding the influence of community composition on C uptake, while respiratory emissions are sensitive to both climatic and compositional change. In synthesis, we emphasize that time is not a driver of C cycling; it is a dimension within which ecosystem drivers such as canopy structure, tree and microbial community composition change. Changes in those drivers, not in forest age, are what control forest C trajectories, and those changes can happen quickly or slowly, through natural processes or deliberate intervention. Stemming from this view and a whole‐ecosystem perspective on forest succession, we offer management applications from this work and assess its broader relevance to understanding long‐term change in other north temperate forest ecosystems.

中文翻译：

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北温带森林生态系统演替中的碳循环：控制和管理意义


尽管取得了几十年的进展，但关于北温带森林碳 （C） 循环的演替轨迹仍有许多未知数。这些变化的驱动因素和机制，包括不同类型干扰的作用，尤其难以捉摸。为了解决这一差距，我们综合了几十年来来自实验时间序列的数据，并在美国密歇根州北部一个经过充分研究、具有区域代表性的野外地点进行了长期监测。我们的研究对两个世纪的演替中地上和地下生态系统组成部分的变化进行了全面评估，将 C 池和通量的时间动态与潜在的驱动因素联系起来，并为森林生态学领域提供了几个概念性见解。我们的第一项进展表明，在重置演替的严重干扰和略微改变演替的部分干扰中，某些生态系统组成部分的时间动态是一致的：这两种干扰类型都会增加土壤氮的可用性，改变真菌群落组成，并改变短寿命的先锋和长寿乔木类群之间的生长和竞争性相互作用。这些变化反过来又影响土壤碳储量、呼吸排放和其他地下过程。其次，我们表明其他一些生态系统组成部分对 C 循环的影响在演替过程中并不一致。例如，冠层结构在演替早期不会影响 C 的吸收，但随着林分的发展而变得重要，并且单个结构特性的重要性在两个世纪的林分发展过程中发生变化。 第三，我们表明，近几十年来，气候变化掩盖或覆盖了群落组成对 C 吸收的影响，而呼吸排放对气候和成分变化都很敏感。在综合中，我们强调时间不是 C 循环的驱动力;它是生态系统驱动因素（如树冠结构、树木和微生物群落组成）发生变化的维度。这些驱动因素的变化，而不是森林年龄的变化，是控制森林 C 轨迹的原因，这些变化可以通过自然过程或有意干预快速或缓慢地发生。基于这一观点和森林演替的整个生态系统视角，我们提供了这项工作的管理应用，并评估了其与理解其他北温带森林生态系统长期变化的更广泛相关性。