报告题目：The impact of toxicants on population dynamics in polluted aquatic environments

报告简介：We develop several toxin-mediated population models (including single-species model, competition model, and predator-prey model) to study the effects of toxicants on long-term dynamics of species in aquatic ecosystems. The models incorporate both direct and indirect toxic effects on the species. The direct effects of toxins typically reduce population abundance by increasing mortality and reducing reproduction. However, the indirect effects, which are mediated through interactions between species plus different vulnerabilities of species to toxins, affect long-term outcomes in many counterintuitive ways. It turns out in toxin-dependent competition dynamics, sublethal toxins may boost coexistence of two species (hence keep species diversity in ecosystems) by reducing the abundance of the predominant species; sublethal toxins may overturn and exchange roles of winner and loser in competition; sublethal toxins may also induce different types of bistability of the competition dynamics, where the competition outcome is doomed to exclusion or coexistence, depending on initial population densities. In toxin-dependent food web dynamics, intermediate toxin concentrations may affect predators disproportionately through biomagnification, leading to reduced abundance of predators and increased abundance of the prey; sublethal toxins may also reduce population variability by preventing populations from fluctuating around a coexistence equilibrium; intermediate environmental toxins may induce bistable dynamics, in which different initial population levels produce different long-term outcomes.

报告人：黄启华，博士，教授，博士研究生导师。 2011年8月在美国 University of Louisiana at Lafayette 获得应用数学博士学位。2011年8月至2016年6月在加拿大 University of Alberta 生物数学中心从事博士后研究工作，合作导师为 Mark Lewis 教授 (加拿大皇家科学院院士，Senior Canada Research Chair in Mathematical Biology)。2016年6月通过西南大学引进人才“聚贤工程”计划被特别评聘为教授，并于2016年9月到西南大学数学与统计学院工作。主要研究方向为生物数学、偏微分方程和数值分析。科研成果主要发表在应用数学期刊SIAM Journal on Applied Mathematics等、生物数学期刊Journal of Mathematical Biology等以及理论生态学期刊Theoretical Ecology等, 其中2017年和2022年发表在SIAM Journal on Applied Mathematics上的论文先后在美国工业与应用数学的官方网站上被报道。目前正主持国家自然科学基金面上项目、重庆市留学人员回国创新支持计划重点项目各一项。

报告时间：6月16日（星期四）下午15:00-16:00

报告地点：腾讯会议，ID：992 178 418

主办单位：扬州大学数学科学学院

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