卫星海洋环境动力学国家重点实验室为增进学术交流，促进实验室对外开放，组织系列“海星系列学术讲座”，邀请国内外知名专家与青年科研人员分享前沿科学动态，讨论最新学术成果，欢迎大家踊跃参加。

召集人：周锋 研究员，张文霞 副研究员

会议时间：11月19日（周二）9:00-11:00

线下会议地点：1号楼1210会议室

线上腾讯会议：718-982-240

腾讯会议链接：https://meeting.tencent.com/dm/9yvBWCTvI7PR

报告人：Jacob Carstensen 教授（丹麦奥胡斯大学 Aarhus University, Denmark）

报告题目：Thresholds and tipping points in marine ecosystems

报告人简介：Jacob Carstensen studied mathematics and statistics with focus on environmental problems. He is the Danish manager for the Baltic Nest Institute. His research has focused on assessing human impacts on marine ecosystems and identifying management responses to maintain good ecosystem functioning. Jacob has published more ~170 papers in peer-reviewed journals, which have been cited ~18000 times. In September 2023, he received the prestigious Björn Carlson Baltic Sea prize together with Professor Daniel Conley.

报告摘要：In ecosystem-ecology, we distinguish between the resistance and the resilience of ecosystems. Resistance is the ability of the ecosystem to remain in its present state despite impacts – anthropogenic or otherwise. Resilience is the ability of the ecosystem to return to its previous state after perturbations. A relatively new insight in ecology is that ecosystems may exist in multiple states, some of which are stable while others are not. It follows from this that ecosystems may undergo so-called “regime shifts” – shifts from one stable state to another. These shifts can happen fast and abruptly rather than gradually, when exceeding a certain threshold or tipping point of an environmental parameter. Furthermore, components of the ecosystem may exhibit hysteresis behavior, meaning that a shift back to a previous state may not take place at the same threshold value. We will also introduce the concept of shifting baselines, which may confound our interpretations of thresholds and hysteresis. In our talk, we will go through the ecological theory and some of the observations supporting the concept of multiple stable states in ecosystems and exemplify the phenomenon with data from Danish coastal ecosystems, focusing primarily oxygen and eelgrass.