报告题目：Impact of dissolved oxygen on the dynamics of plankton in shallow lakes ( 浅水湖泊中溶解氧对浮游生物动力学的影响)
报告时间：2016年11月20日（周日）上午9:00-10:00
报告地点：理学院二楼会议室
报告人：朱怀平，现任加拿大约克大学教授，并行计算与模拟实验室主任，曾任约克大学研究生项目主任。长期从事分支理论及其应用、希尔伯特第十六问题、种群生态学与传染病学的数学分析研究、气候变化模拟和影响、以及蚊虫疾病的实时预报和控制等研究工作。在数学及生物数学的国际顶级或高水平期刊上累计发表文章100多篇。解决了著名的希尔伯特第16问题关于幂零图周期重数有限性的问题，是目前这一领域国际最著名专家之一，在国际著名的微分方程杂志发表了单篇长达112页论文。多次作为大会主席组织举办了动力系统分支理论以及应用，生物数学，气候变化以及影响等学术会议，并先后在重要国际会议做特邀报告20余次。作为项目负责人获得加拿大国家创新基金(CFI)，国家工程和自然科学基金会(NSERC)，加拿大健康研究院（CIHR），加拿大公共卫生部，安大略省卫生部，安大略省环境部、科技部等资助。2003年获加拿大国家创新基金会基础创新奖，2007年获安大略省青年科学研究奖。
报告摘要：In shallow lakes, dissolved oxygen plays an important role in the interactions between phytoplankton and zooplankton and in the outbreaks of algal blooms. The species diversity and density of benthic macroinvertebrates are also significantly correlated with the concentration of dissolved oxygen. It is interesting but also challenging to model the ecological system in water body like shallow water lakes. In this talk, considering the effect of dissolved oxygen concentration on the filtering rate of zooplankton, I will propose a simple dissolved oxygen- phytoplankton-zooplankton (DOPZ) model to study how dissolved oxygen enriches the dynamical behaviors of plankton ecosystem and triggers an algal bloom. I will discuss the stability of boundary equilibria, the existence of multiple positive equilibria and analyze the local dynamics by studying the singularity of a triple equilibrium on a manifold. Preliminary analysis of the system reveal some complex dynamics, including saddle-node bifurcations, Hopf bifurcation, and transcritical bifurcation. I will then illustrate our theoretical findings by performing some numerical stimulation with suitable bifurcation parameters, and give the corresponding biological interpretations for the interesting phenomena presented in the model. This is a joint work with Juan Li and Yongzhong Song.