Date of Award

5-2020

Document Type

Thesis

Degree Name

Master of Science (MS)

College/School

College of Science and Mathematics

Department/Program

Applied Mathematics and Statistics

Thesis Sponsor/Dissertation Chair/Project Chair

Eric Forgoston

Committee Member

Lora Billings

Committee Member

David Trubatch

Subject(s)

Food chains (Ecology)--Mathematical models, Stochastic models

Abstract

Studies on both model-based and empirical food webs have shown that per- turbations to an ecological community can cause a species to go extinct, often resulting in the loss of additional species in a cascade of secondary extinctions. These e ects can seriously debilitate a food web and threaten the existence of an ecosystem. Here, we consider niche model-based food webs with internal noise and investigate the e ects of a control on a secondary extinction cas- cade triggered by a noise-induced extinction. We show that the forced removal of a nonbasal species immediately after a primary extinction can extend the mean time to extinction of individual nonbasal species as well as that of the complete extinction cascade. An analysis of numerical and statistical results illustrates the e ectiveness of a control in delaying the mean time to extinction for endangered species in stochastic food webs.

File Format

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