Ecosystem respiration is a major component of the global terrestrial carbon cycle and is strongly influenced by temperature. The global extent of the temperature–ecosystem respiration relationship, however, has not been fully explored. Here, we test linear and threshold models of ecosystem respiration across 210 globally distributed eddy covariance sites over an extensive temperature range. We find thresholds to the global temperature–ecosystem respiration relationship at high and low air temperatures and mid soil temperatures, which represent transitions in the temperature dependence and sensitivity of ecosystem respiration. Annual ecosystem respiration rates show a markedly reduced temperature dependence and sensitivity compared to half-hourly rates, and a single mid-temperature threshold for both air and soil temperature. Our study indicates a distinction in the influence of environmental factors, including temperature, on ecosystem respiration between latitudinal and climate gradients at short (half-hourly) and long (annual) timescales. Such climatological differences in the temperature sensitivity of ecosystem respiration have important consequences for the terrestrial net carbon sink under ongoing climate change.

生态系统呼吸是全球陆地碳循环的主要组成部分，并受温度的强烈影响。然而，温度-生态系统呼吸关系的全球范围尚未得到充分探索。在这里，我们在广泛的温度范围内测试了 210 个全球分布的涡流协方差点的生态系统呼吸的线性和阈值模型。我们发现了全球温度-生态系统呼吸关系在高、低气温和中土温度下的阈值，这代表了生态系统呼吸的温度依赖性和敏感性的转变。与半小时速率相比，年度生态系统呼吸速率显示出明显降低的温度依赖性和敏感性，以及空气和土壤温度的单一中间温度阈值。我们的研究表明，包括温度在内的环境因素对生态系统呼吸的影响在短（半小时）和长（年）时间尺度上的纬度和气候梯度之间存在差异。生态系统呼吸温度敏感性的这种气候差异对持续气候变化下的陆地净碳汇具有重要影响。