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

University Of Connecticut, Storrs CT

Investigators

Abstract

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.