Department of Ecology and Evolutionary Biology, University of Toronto, 25 Harbord St, Toronto, ON, M5S 3G5, Canada.
Ecol Lett. 2014 Aug;17(8):902-14. doi: 10.1111/ele.12307. Epub 2014 Jun 3.
Changing temperature can substantially shift ecological communities by altering the strength and stability of trophic interactions. Because many ecological rates are constrained by temperature, new approaches are required to understand how simultaneous changes in multiple rates alter the relative performance of species and their trophic interactions. We develop an energetic approach to identify the relationship between biomass fluxes and standing biomass across trophic levels. Our approach links ecological rates and trophic dynamics to measure temperature-dependent changes to the strength of trophic interactions and determine how these changes alter food web stability. It accomplishes this by using biomass as a common energetic currency and isolating three temperature-dependent processes that are common to all consumer-resource interactions: biomass accumulation of the resource, resource consumption and consumer mortality. Using this framework, we clarify when and how temperature alters consumer to resource biomass ratios, equilibrium resilience, consumer variability, extinction risk and transient vs. equilibrium dynamics. Finally, we characterise key asymmetries in species responses to temperature that produce these distinct dynamic behaviours and identify when they are likely to emerge. Overall, our framework provides a mechanistic and more unified understanding of the temperature dependence of trophic dynamics in terms of ecological rates, biomass ratios and stability.
改变温度可以通过改变营养相互作用的强度和稳定性来显著改变生态群落。由于许多生态速率受到温度的限制，因此需要新的方法来理解多个速率的同时变化如何改变物种及其营养相互作用的相对表现。我们开发了一种能量方法来确定营养水平之间的生物量通量和现存量之间的关系。我们的方法将生态速率和营养动态联系起来，以衡量营养相互作用强度随温度的变化，并确定这些变化如何改变食物网的稳定性。它通过使用生物量作为通用的能量货币，并隔离所有消费者-资源相互作用中常见的三个依赖于温度的过程来实现这一点：资源的生物量积累、资源消耗和消费者死亡率。使用这个框架，我们澄清了温度何时以及如何改变消费者与资源生物量的比例、平衡弹性、消费者变异性、灭绝风险以及瞬态与平衡动态。最后，我们描述了物种对温度响应的关键不对称性，这些不对称性产生了这些不同的动态行为，并确定了它们可能出现的时间。总的来说，我们的框架提供了一个基于生态速率、生物量比和稳定性的对营养动态温度依赖性的机制和更统一的理解。
