Population and community consequences of cross-ecosystem resource subsidies

许多生态系统依赖跨生态系统资源补贴，如落叶或落入溪流中的陆地无脊椎动物，作为维持其生产力和生物多样性的关键能源。这种依赖对于以碎屑为基础、但包括许多其他资源类型和生态系统类型的生态系统来说尤其明显。资源补贴跨越了许多生态系统边界，但在陆地-水界面上最为明显。这些资源被认为是对基础资源就地生产的补贴，其部分特点是由捐助者控制，因为消费者不能影响补贴资源的投入率，因此没有或可以忽略直接反馈。已经证明，这些资源是必不可少的，过去5年内在这个主题上的工作使理论发展到了预测性、量化模型的阶段。我们通过量化对消费者群体及其社区的相对影响，在这些补贴资源的流入和流出方面取得了进展。我们现在能够就这些补贴资源与消费者动态之间的关系的数量形式提出更具体的问题。此外，我们可以问资源补贴如何影响社区进程，包括稳定性、社区集会、生产力和侵入性等问题。 在这项提案中，我打算利用溪流和河岸生态系统中的实验方法来解决问题，以推动基于补贴的系统的消费者资源动态领域的发展。这些问题围绕着资源补贴的时机、规模、持续时间和质量的影响。这些问题涉及人口和社区一级的后果、加强或减少营养级联的可能性、食物网的稳定性、研究消费者动态对补贴反应的响应面，以及资源流动的质量和时间的影响。这些实验将利用NSERC、CFI和UBC过去对我们在UBC的Malcolm Knapp研究森林的基础设施的投资。

Many ecosystems depend on cross-ecosystem resource subsidies, such as leaf litter or terrestrial invertebrates falling into streams, as key energy resources to sustain their productivity and biodiversity. This dependence is particularly clear for ecosystems that are detritus-based, but include many other resource types and ecosystem types. Resource subsidies cross many ecosystem boundaries, but are most obvious across the land-water interface. These resources are considered to be subsidies to the in situ production of basal resources, and are characterised in part by being donor-controlled since consumers cannot affect the rates of input of the subsidy resource, and therefore there is no, or negligible, direct feedback. It has been demonstrated that these resources are essential, and work on the topic within the past 5 years have allowed theory to advance to the stage of predictive, quantitative models. We have made progress on flows of these subsidy resources into and out of streams by quantifying the relative effects on consumer populations and their communities. We are now able to ask more specific questions about the quantitative form of the relationships between these subsidy resources and the consumers' dynamics. Moreover, we can ask how resource subsidies affect community processes, including questions about stability, community assembly, productivity, and invasibility. In this proposal I intend to address questions to advance the field of consumer-resource dynamics for subsidy-based systems using experimental approaches in stream and riparian ecosystems. These questions revolve around the effects of the timing, magnitude, duration and quality of resource subsidies. The questions address population and community level consequences, possibility of enhancing or diminishing trophic cascades, the stability of foodwebs, studying the response surfaces of consumer dynamics in response to subsidies, and effects of quality and timing of resource flows. These experiments will take advantage of past investments by NSERC, CFI and UBC in our infrastructure at UBC's Malcolm Knapp Research Forest.