报告主题：Lake-mediated refugia: how island size and shoreline position filter dispersal, disturbance and climate
主讲人：Scott Nielsen
主持人：阎恩荣 教授
讲座时间：2026年11月10日9:15am
讲座地点：闵行校区 资环楼 148会议室
报告人简介：
Dr. Scott Nielsen ,加拿大阿尔伯塔大学可再生资源系保护生物学教授。他于2008年创立了应用保护生态学实验室（Applied Conservation Ecology Lab），并一直领导一研究团队考察生物多样性对林业与能源开发的响应，以及减缓/恢复措施的有效性。他的研究兴趣在于陆地生态学（植物与动物）及其在保护生物地理学领域的应用，所采用的方法将野外物种调查与遥感、GIS 及统计建模/预测相结合。其工作的地理重点为加拿大西部与中部的北方林和半北方林，以及加拿大落基山山地森林。成果发表于 Nature Climate Change、Global Change Biology、Biological Conservation、Journal of Applied Ecology 等期刊。
报告内容简介：
Lakes create refugia by filtering what reaches land. Here, I will combine studies from my lab on three boreal lake-island systems to examine three key filters: isolation, disturbance, and climate. On Lake-of-the-Woods islands, isolation acts as a dispersal filter. Several small islands held as many plant and butterfly species as one large island (special patch-set controlling for area). However, dispersal traits mattered for butterflies: island area and isolation reduced abundance for less mobile and rarer species. At Cree Lake, water acts as a disturbance filter: island area and isolation strongly predict which islands burn (odds of burning were 7.5-fold higher per 10-fold increase in area), driving major shifts in soils and vegetation. Small islands (<3 ha) showed strong fire-refugia effects, resulting in sprucefeather moss communities. As islands reached 9 ha (lichens > bryophytes), they transitioned to lichen woodland communities, with increased tree spacing and reindeer lichens dominating. Along Lake Superior, cold upwelling water and shoreline winds act as a local climate filter. Shorelines averaged 5 °C cooler in summer than nearby inland sites (>19 °C cooler on hot days), demonstrating local microclimatic buffering, with shoreline temperatures of this temperate region more typical of arctic-alpine climates >500 km to the north. Indeed, Lake Superior shorelines contain 58 disjunct arcticalpine plants, illustrating its role as a major climatic refugium, with local disjuncts tied to shoreline geometry and offshore water depth. In each system, an island's size or position relative to water determines whether it escapes dispersal limitation, fire, or heat.
