Omnivorous Fish and the Stability of Aquatic Food Webs

奖项摘要：Michael J. VanniMiami大学提案号：deb9982124项目建议研究杂食性鱼类沙棘鱼在水生食物网抵抗和恢复大脉冲营养扰动中的作用。他们假设，与没有杂食性鱼类的食物网相比，像这些鲱鱼这样的杂食性鱼类的食物网对外来营养物质的扰动更稳定（即，抗性和弹性）。这种稳定性的增强可能是由于杂食性鱼类从沉积物中输送了大量稳定的营养物质，或者由于将杂食性鱼类纳入食物网而形成了额外的营养联系。这项工作的目的是测试由杂食稳定性假设产生的预测，并确定导致观察到的稳定性变化的潜在机制。将进行重复的池塘实验，以评估鱼类如何影响食物网对营养物质脉冲的抵抗力和恢复力，如果是这样，这种机制是通过营养物质运输还是通过食物网结构作用，或者两者兼而有之。建模还将用于探索杂食性鱼类在一系列生态系统结构和扰动类型的水生食物网稳定性中的作用。

AWARD ABSTRACT Michael J. VanniMiami UniversityProposal Number: DEB-9982124The PI proposes to investigate the role of an omnivorous fish, the gizzard shad, in the resistance and resilience of aquatic food webs to perturbations in the form of large pulses of nutrients. They hypothesize that food webs with omnivorous fish, like these shad, are more stable (i.e., resistant and resilient) in repines to perturbations of allochthonous nutrients than are those without omnivorous fish. The enhanced stability might be due to the large steady supply of nutrients transported by omnivorous fish from sediments or to the additional trophic links formed by incorporating the omnivorous fish in the food webs. The objectives of this work are to test predictions generated by the omnivory-stability hypothesis and to determine the underlying mechanisms responsible for observed changed in stability. Replicated pond experiments will be performed to assess how fish influence resistance and resilience of food webs to pulses of nutrients, and if so, whether the mechanism is via nutrient-transport or via a food web-structure role, or both. Modeling will also be used to explore the role of omnivorous fish in the stability of aquatic food webs over a range of ecosystem structures and perturbation types.