Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, P. R. China.
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, P. R. China.
Nat Ecol Evol. 2023 Sep;7(9):1379-1387. doi: 10.1038/s41559-023-02121-w. Epub 2023 Jul 24.
Ecosystem respiration (ER) is among the largest carbon fluxes between the biosphere and the atmosphere. Understanding the temperature response of ER is crucial for predicting the climate change-carbon cycle feedback. However, whether there is an apparent optimum temperature of ER ([Formula: see text]) and how it changes with temperature remain poorly understood. Here we analyse the temperature response curves of ER at 212 sites from global FLUXNET. We find that ER at 183 sites shows parabolic temperature response curves and [Formula: see text] at which ER reaches the maximum exists widely across biomes around the globe. Among the 15 biotic and abiotic variables examined, [Formula: see text] is mostly related to the optimum temperature of gross primary production (GPP, [Formula: see text]) and annual maximum daily temperature (T). In addition, [Formula: see text] linearly increases with T across sites and over vegetation types, suggesting its thermal adaptation. The adaptation magnitude of [Formula: see text], which is measured by the change in [Formula: see text] per unit change in T, is positively correlated with the adaptation magnitude of [Formula: see text]. This study provides evidence of the widespread existence of [Formula: see text] and its thermal adaptation with T across different biomes around the globe. Our findings suggest that carbon cycle models that consider the existence of [Formula: see text] and its adaptation have the potential to more realistically predict terrestrial carbon sequestration in a world with changing climate.
生态系统呼吸（ER）是生物圈与大气之间最大的碳通量之一。了解 ER 的温度响应对于预测气候变化-碳循环反馈至关重要。然而，ER 是否存在明显的最适温度 ([Formula: see text])，以及它如何随温度变化，仍知之甚少。本研究分析了来自全球通量网（FLUXNET）的 212 个站点的 ER 温度响应曲线。结果发现，183 个站点的 ER 呈抛物线温度响应曲线，并且在全球各个生物群落中广泛存在 ER 达到最大值的最适温度 ([Formula: see text])。在所研究的 15 个生物和非生物变量中，[Formula: see text]主要与总初级生产力 (GPP，[Formula: see text])和年最大日温 (T) 的最适温度有关。此外，[Formula: see text]在站点和植被类型之间呈线性增加，表明其具有热适应性。[Formula: see text]的适应幅度，即单位 T 变化引起的 [Formula: see text]变化，与 [Formula: see text]的适应幅度呈正相关。本研究为全球不同生物群落中 [Formula: see text]的广泛存在及其对 T 的热适应性提供了证据。研究结果表明，考虑到 [Formula: see text]的存在及其对 T 的适应，碳循环模型有可能更真实地预测气候变化下陆地碳的固存。
