Collaborative Research: Mathematical and experimental analysis of the interaction between competitors and a shared predator - from patches to landscapes

Auburn University At Montgomery, Montgomery AL

Investigators

Abstract

Ecologists today are faced with a most pressing concern: ensuring long-term survival and coexistence of species in the face of habitat loss and fragmentation. An innovative aspect of this project is the close integration of experimental and mathematical analyses to investigate impacts of habitat fragmentation, interspecific competition, and predation on coexistence of species at patch and landscape levels. This research will provide a more comprehensive understanding of the complex relationships that drive ecological systems and contribute to the development of effective conservation strategies. Two important questions regarding biology of interacting species are considered: 1) do predators affect the relationship between density and prey emigration, Allee effects and local or regional stability of prey species? and 2) does the presence of predators affect occurrence or strength of competition-dispersal, competition-reproduction or dispersal-reproduction tradeoffs and therefore coexistence of competitors? The project will also provide significant contributions towards analysis of mathematical models created to study this behavior via development of new tools to better understand model dynamics. Project results will be disseminated to the ecological and mathematical communities through various media including peer-reviewed mathematical and ecology journals and talks at national conferences. This project will involve training of graduate and undergraduate students through mentorship of independent research projects and PI-hosted workshops, with a session geared toward high-school students/teachers that focuses on illustrating value and applicability of mathematical models and ecological experiments to address societal problems. Moreover, an app that estimates key dispersal parameters from field data will be created and made publicly available. This project combines reaction-diffusion models, mathematical analysis, and experimental research to investigate how habitat fragmentation, conditional dispersal, interspecific competition, and predation influence population dynamics and species coexistence at single patch to landscape scales. The project will involve the study of diffusive Lotka-Volterra competition and predator-prey systems with nonlinear boundary conditions designed to model how density dependent emigration (DDE) affects the dynamics of species at different spatial scales and experiments with two Tribolium flour beetle species and a shared natural enemy to measure DDE relationships and life-history tradeoffs under predation pressure. The Investigators will develop and analyze mathematical models based on the experimental data to explore effects of DDE on coexistence, invasion, and pattern formation. This project is expected to be novel and significant by providing (1) much-needed experimental evidence that interspecific competitors and predators affect boundary behavior namely, the strength and form of DDE, and important life-history tradeoffs linked to species coexistence; (2) the first theoretical framework for the effects of conditional dispersal on the population dynamics and coexistence of competing species and a shared predator in fragmented landscapes; and (3) a significant contribution toward the analysis of systems of elliptic boundary value problems with nonlinear boundary conditions, to better understand model dynamics. Results from this study are expected to be applicable to conservation programs and reserve design. Specifically, this model framework can be used to investigate how Allee-like effects can arise from context-dependent dispersal to affect minimum patch sizes, carrying capacities, density-area relationships, species-area relationships, and multiple stable states. This project is jointly funded by the MPS Division of Mathematical Sciences (DMS) through the Mathematical Biology Program, the Established Program to Stimulate Competitive Research (EPSCoR), and the BIO Division of Environmental Biology through the Population and Community Ecology Cluster. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.