Predicting the effects of warming: from individual physiology to emergent ecosystem function

了解个体的生理学如何约束生态系统动力学，对于预测气候变化对全球生物地球化学循环的影响具有根本的重要性。我最近的研究表明，在温度急剧上升后，呼吸速率的加速速度比生长速率快。这一现象的一个直接但未被探索的后果是，生长成本随温度增加而增加，导致预测温暖的环境应该以通过食物链的能量转移效率较低为特征，在较高的营养水平下生物量较少。在这里，我建议调查这一新的预测与研究计划，涉及的发展和整合的代谢，食物网和进化理论与一系列的实验和现场测试连接个人生理生态系统和食物网结构。重要的是，这是第一次，其中短期（生理）和长期适应变暖的反应将被测量的多个相互作用的物种，包括不同的营养水平，以预测和测试在生态系统尺度的紧急模式。因此，该方案旨在提供一个预测框架，以帮助预测随着气候变暖，水生生态系统的功能和动态将如何发挥作用。发展这样一种理解具有根本和实际的重要性。从根本上说，这一框架有望通过梳理能量约束直接造成的影响，协调解释变暖对生态系统功能影响的多种机制。例如，在实践中，通过预测大小分布和生态系统生物量组成的变化，这种理解还将直接有助于在区域尺度上改善不同气候变化情景下的生态系统管理。

Understanding how the physiology of individuals constrain ecosystem dynamics is of fundamental importance to predicting the effects of climate change on global biogeochemical cycles. My recent research demonstrates that rates of respiration accelerate at a faster pace than growth rates following acute increases in temperature. A direct, but unexplored consequence of this phenomenon is that the cost of growth increases with temperature, leading to the prediction that warmer environments should be characterised by less efficient energy transfer through food chains with less biomass at higher trophic levels. Here I propose to investigate this novel prediction with a research programme that involves the development and integration of metabolic, food web, and evolutionary theories with a series of experimental and field tests linking individual physiology to ecosystem and food web structure. Importantly, this is the first time in which short- (physiological) and long-term adaptation responses to warming will be measured for multiple interacting species comprising different trophic levels in order to predict and test emergent patterns at the ecosystem scale. This programme thus aims at delivering a predictive framework to help forecast how the functioning and dynamics of aquatic ecosystems will play out as the climate warms. Developing such an understanding is of both fundamental and practical importance. Fundamentally, this framework holds promise to reconcile the multiple mechanisms invoked to explain the effects of warming on ecosystem functioning, by teasing out the effects directly caused by energetic constraints. In practical terms, for example, such an understanding would also directly help improve ecosystem management under different climate change scenarios at regional scales by predicting changes in size distribution and ecosystem biomass composition.