ECOLOGICAL AND EVOLUTIONARY RESILIENCE OF AQUATIC COMMUNITIES TO THE CLIMATE-MEDIATED EXPANSION OF AN APEX PREDATOR

生态学的一个持续挑战是了解生态系统如何对环境干扰作出反应。气候变化就是这样一种干扰，预计将导致全球生物多样性的重组，包括物种地理分布的变化和灭绝率的增加。当地物种种群的变化可能影响生态系统的功能及其为人类提供的服务。然而，如果更能适应新气候的物种能够迁移，或者当地人口能够适应这些变化，自然生态系统可能会比我们想象的更有弹性。在这个项目中，研究人员将操纵整个池塘，以了解这些生态系统对气候引起的顶级水生捕食者扩张的适应程度。随着冬季变暖，大理石纹蝾螈迅速在新英格兰新适宜的临时池塘中定居。大理石纹蝾螈是这些池塘的顶级捕食者，可以严重减少生物多样性，并将池塘生态系统转变为高藻类生产的状态。该项目将对社会产生更广泛的影响，而不仅仅是对基础科学和自然保护做出贡献。调查人员将为K-12教师创建一个科学实习项目，并为来自代表性不足群体的学生创建一个本科实习项目。他们还将开发一个连接远程摄像机的系统，记录和播放每年一次的两栖动物迁徙，作为向公众宣传的一种手段。在气候变化促使顶级捕食者快速扩张的地区，研究人员将量化移民和适应进化如何促进生态和进化救援。这项工作将集中在物种迁移产生的生态恢复力上，这种恢复力可以恢复多样性并取代失去的功能角色，以及中间消费者的适应性进化，这些中间消费者先前被证明可以调节顶端捕食者对群落结构的影响。该项目通过以下方式推进基础和应用问题：1)在平行的、重复的、全生态系统的实验中进行复原力理论的首批测试之一；2)允许对恢复力的生态机制与进化机制进行比较；3)挑战生物响应预测忽略景观连通性和适应性变化的现有范式；4)开启了对野生脊椎动物进化的重要长期研究；5)对顶端捕食者在全球变暖的环境中扩张时如何改变淡水系统形成一种概括性的理解。该项目采用了多层次的方法，以便深入了解跨越空间和时间的捕食者引入的两种基本反应，从而有助于建立对生态进化对食物网变化的抵抗力的更广泛、更机械的理解。

An ongoing challenge in ecology is to understand how ecosystems respond to environmental disturbances. Climate change is one such disturbance that is expected to result in a re-organization of global biodiversity, including shifts in species geographic distribution and increases in rates of extinctions. Alterations in local species populations may impact the functioning of ecosystems and the services they provide for humans. However, natural ecosystems might prove more resilient that we think if species better adapted to new climates can immigrate or if local populations can adapt to the changes. In this project, researchers will manipulate entire ponds to understand the degree to which these ecosystems are resilient to the climate-induced expansion of a top aquatic predator. As winters warm, the marbled salamander is rapidly colonizing newly suitable temporary ponds in New England. Marbled salamanders are top predators in these ponds and can strongly reduce biodiversity and shift pond ecosystems to a state characterized by high algal production. The project will have broader impacts on society beyond contributing to fundamental science and conservation. The investigators will create a scientific internship for K-12 teachers and an undergraduate internship focusing on students from underrepresented groups. They will also develop a system of linked remote video cameras to record and broadcast the annual amphibian migration, as a means of public outreach.In a region where climate change is promoting the rapid expansion of a top predator, the investigators will quantify how immigration and adaptive evolution facilitate ecological and evolutionary rescue. The work will focus on ecological resilience originating from the immigration of species that can restore diversity and replace lost functional roles and the adaptive evolution of an intermediate consumer previously shown to mediate the impacts of the apex predator on community structure. The project advances fundamental and applied questions by 1) performing one of the first tests of resilience theory in parallel, repeated, whole-ecosystem experiments; 2) allowing a comparison of ecological versus evolutionary mechanisms of resilience; 3) challenging the existing paradigm that predictions about biotic responses can ignore landscape connectivity and adaptive variation; 4) initiating an important long-term study on evolution in wild vertebrates; and 5) developing a generalizable understanding of how apex predators alter freshwater systems as they expand in a warming world. The project takes a multi-tiered approach in order to develop insights about two fundamental responses to predator introductions across space and time to contribute to building a broader, more mechanistic understanding of eco-evolutionary resistance to food web changes.