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AM Seminar: How temporally autocorrelated fluctuations alter ecological outcomes

Speaker Name: 
Sebastian Schreiber
Speaker Title: 
Professor
Speaker Organization: 
University of California, Davis
Start Time: 
Monday, January 27, 2020 - 4:00pm
End Time: 
Monday, January 27, 2020 - 5:00pm
Location: 
BE 372
Organizer: 
Abhishek Halder

Abstract

All species experience temporal fluctuations in environmental conditions such as temperature, precipitation, resource availability or mortality risk. These fluctuations often are positively or negatively autocorrelated e.g. wetter years tending to be followed by wetter years, or seasons of high mortality tending to be followed by seasons of low mortality. How these autocorrelations influence population persistence and species coexistence is, largely, an open problem. To address this problem, I will discuss recent mathematical results on persistence (i.e. a tendency for all the species' densities to stay bounded away from extinction) and extinction (i.e. a positive probability that one or more of the species' densities asymptotically goes to zero) for stochastic difference equations. The class of equations for which these results apply are sufficiently general to account for any number of species, discrete population structure within each species (e.g. spatial or age structure), trait evolution, and environmental feedbacks (e.g. plant-soil feedbacks). To illustrate the utility of these results to address the open problem, I will apply them to models of (i) trait evolution of a single species, (ii) competing species, and (iii) species sharing a common predator. In each case, temporal autocorrelations can alter ecological outcomes by allowing for evolutionary rescue in (i), and mediating coexistence, reversing species dominance, or promoting a stochastic priority effect in (ii) and (iii).

Bio

Sebastian Schreiber is population biologist and mathematician, wrestling with the complexities of nature, armed with the theories of stochastic processes and dynamical systems. He got his Ph.D. in Mathematics on smooth ergodic theory from the University of California, Berkeley. Prior to becoming a Professor of Evolution and Ecology at University of California, Davis, he was an Assistant and Associate Professor of Mathematics at Western Washington University and the College of William and Mary. He is an editor for Theoretical Population Biology and a member of the editorial boards of Ecology, Journal of Mathematical Biology, Discrete and Continuous Dynamical Systems, and Theoretical Ecology. 

Event Type: 
Event