Climate refugia along Lake Superior’s shores:disjunct arctic-alpine plants rely on cool shoreline temperatures but are restricted to highly exposed habitat under climate warming  

沿苏必利尔湖岸的气候避难所:北极-高山植物分布依赖于凉爽的湖岸温度,在气候变暖下却被高度暴露的栖息地所限制

作　　者：Ashley Hillman Scott E.Nielsen 

机构地区：[1]Department of Renewable Resources,University of Alberta,Edmonton,AB T6G 2R3,Canada

出　　处：《Journal of Plant Ecology》2024年第4期23-41,共19页植物生态学报（英文版）

基　　金：supported by the Natural Sciences and Engineering Research Council of Canada(RGPIN-2019-06040).

摘　　要：Climate refugia can serve as a remnant habitat or stepping stones for species dispersal under climate warming.The largest freshwater lake by surface area,Lake Superior,USA and Canada,serves as a model system for understanding cooling-mediated local refugia,as its cool water temperatures and wave action have maintained shoreline habitats suitable for southern disjunct populations of arctic-alpine plants since deglaciation.Here,we seek to explain spatial patterns and environmental drivers of arctic-alpine plant refugia along Lake Superior’s shores,and assess future risk to refugia under moderate(+3.5℃)and warmest(+5.7℃)climate warming scenarios.First,we examined how the interactive effects of summer surface water temperatures and wind affected onshore temperatures,resulting in areas of cooler refugia.Second,we developed an ecological niche model for the presence of disjunct arctic-alpine refugia(pooling 1253 occurrences from 58 species)along the lake’s shoreline.Third,we fit species distribution models for 20 of the most common arctic-alpine disjunct species and predicted presence to identify refugia hotspots.Finally,we used the two climate warming scenarios to predict changes in the presence of refugia and disjunct hotspots.Bedrock type,elevation above water,inland distance,July land surface temperature from MODIS/Terra satellite and near-shore depth of water were the best predictors of disjunct occurrences.Overall,we predicted 2236 km of the shoreline(51%)as disjunct refugia habitat for at least one species under current conditions,but this was reduced to 20% and 7% with moderate(894 km)and warmest(313 km)climate change projections.气候避难所可以作为气候变暖下物种扩散的残余栖息地或跳板。本研究将世界上表面积最大的淡水湖——美国与加拿大交界的苏必利尔湖作为一个模型系统,用于理解冷却介导的局部避难所。自冰川消退以来,该湖的低水温和波浪作用一直维持着北极-高山植物南方独立居群的湖岸适宜栖息地。本研究旨在解释苏必利尔湖岸边北极-高山植物避难所的空间模式和环境驱动因素,并评估在中等排放情景(+3.5℃)和高排放情景(+5.7℃)下避难所的未来风险。首先,我们研究了夏季表层水温和风的交互作用是如何影响湖岸温度,从而形成凉爽的避难区域。其次,我们通过汇总58个物种的1253个发生数据,开发了一个生态位模型,用于预测湖岸边离群的北极-高山避难所。第三,我们为20种最常见的北极-高山离群物种拟合了物种分布模型,进而识别避难热点。最后,我们使用两个气候变暖情景预测避难所和离群热点的变化。研究结果表明,基岩类型、水上高度、内陆距离、MODIS/Terra卫星的7月陆地表面温度和近岸水深是独立居群出现的最佳预测因子。在当前条件下,我们预测离湖岸2236 km(51%)是至少一种物种的离群避难栖息地,但在中等(894 km)和最高(313 km)气候变化预测下,这一比例分别减少至20%和7%。

关 键 词：climate refugia disjunct populations lake effect Lake Superior species distribution models 

分 类 号：Q948[生物学—植物学]