题  目: Population spread and persistence in streams 

报告人 ：Dr. Yu Jin  Department of Mathematics, University of Nebraska-Lincoln, Lincoln, NE, USA 

时  间： 5月17日 下午3:00-4:00

地  点： 管研楼1518 

Abstract: The drift paradox asks how stream-dwelling organisms can persist, without being washed out, when they are continuously subject to the unidirectional stream flow. We consider the influence of seasonal variations in environmental factors that govern population growth and dispersal on the drift paradox, using a time-periodic integro-differential equation model. We establish upstream and downstream spreading speeds under the assumption of periodically fluctuating environments, and show the existence of periodic traveling waves. We also address the critical domain size problem for seasonally fluctuating stream environments and determine how large a reach of suitable stream habitat is needed to ensure population persistence of a stream-dwelling species. We characterize the fluctuating environments in terms of seasonal correlations between the flow, transfer rates, diffusion and settling rates, and we investigate the effect of such correlations on the spreading speeds and critical domain size problem. 

主办单位：中国科学技术大学数学科学学院  国家数学与交叉科学中心合肥分中心 

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