Ecological and Evolutionary Constraints on the Temperature Dependence of Microbial Community Respiration

微生物呼吸的温度依赖性仍然是碳循环对气候变化反应的最大不确定性之一。在短时间内，代谢率随温度呈指数增长。温度诱导的微生物呼吸增加将导致进入大气的碳通量增加，这可能导致更多的变暖，从而产生积极的反馈。然而，来自多个生态系统类型的研究表明，在长期变暖的情况下，群落呼吸的温度敏感性降低。呼吸对温度的反应减弱将减少或消除正反馈，目前的人为排放将导致较少的变暖。导致微生物呼吸温度敏感性降低的潜在生态和进化机制仍有待讨论，它们的相对重要性尚未达成共识，阻碍了在预测模型中捕捉这一重要现象的努力。MICROADAPT项目的目的是利用微生物模型系统进行一系列创新实验，确定快速进化和物种分类如何影响微生物群落呼吸的温度依赖性。在与实验数据的协同中，我们开发了新的数学理论，该理论捕捉了塑造微生物代谢的紧急温度响应的生态和进化机制。

The temperature dependence of microbial respiration remains one of the largest uncertainties in the response of the carbon cycle to climate change. Over short timescales, metabolic rates increase exponentially with temperature. A temperature-induced increase in microbial respiration will lead to an increase in the flux of carbon into the atmosphere, which may lead to more warming, resulting in a positive feedback. However, studies from multiple ecosystem types, have shown a decrease in the temperature sensitivity of community respiration under long-term warming. A dampened response of respiration to temperature would reduce or remove the positive feedback and current anthropogenic emissions would lead to less warming. The underlying ecological and evolutionary mechanisms that contribute to a dampening of the temperature sensitivity of microbial respiration are still up for debate and no consensus has been reached on their relative importance, hindering efforts to capture this important phenomenon in predictive models. The aim of the MICROADAPT project is to determine how rapid evolution and species sorting shape the temperature dependence of microbial community respiration using an array of innovative experiments with a microbial model system. In synergy with the experimental data, we develop novel mathematical theory that capture the ecological and evolutionary mechanisms that shape the emergent temperature response of microbial metabolism.