Predicted climate-induced changes in the Great Lakes include increased variability in water levels, which may shift periphyton habitat. Our goal was to determine the impacts of water level changes in Lake Superior on the periphyton community assemblages in the Keweenaw Peninsula with different surface geology. At three sites, we identified periphyton assemblages as a function of depth, determined surface area of periphyton habitat using high resolution bathymetry, and estimated the impact of water level changes in Lake Superior on periphyton habitat. Our results suggest that substrate geology influences periphyton community assemblages in the Keweenaw Peninsula. Using predicted changes in water levels, we found that a decrease in levels of 0.63 m resulted in a loss of available surface area for periphyton habitat by 600 to 3000 m² per 100 m of shoreline with slopes ranging 2 to 9°. If water levels rise, the surface area of substrate will increase by 150 to 370 m² per 100 m of shoreline, as the slopes above the lake levels are steeper (8–20°). Since periphyton communities vary per site, changes in the surface area of the substrate will likely result in a shift in species composition, which could alter the structure of aquatic food webs and ecological processes.

中文翻译：

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美国密歇根州苏必利尔湖中不断变化的水位影响到Keweenaw半岛的附生硅藻组合

预测的五大湖由气候引起的变化包括水位变化的增加，这可能会改变水生植物的栖息地。我们的目标是确定苏必利尔湖水位变化对具有不同地表地质的基韦诺半岛的附生植物群落的影响。在三个地点，我们确定了附生植物组合与深度的关系，使用高分辨率测深仪确定了附生植物栖息地的表面积，并估算了苏必利尔湖水位变化对附生植物栖息地的影响。我们的结果表明，底物地质会影响Keweenaw半岛的水生植物群落组合。使用预测的水位变化，我们发现水位下降0.63 m导致水生植物栖息地的可用表面积减少了600至3000 m每100 m海岸线²个，倾斜范围为2至9°。如果水位上升，则每100 m海岸线的底物表面积将增加150至370 m ²，因为湖面以上的坡度更陡（8–20°）。由于浮游植物的群落在每个地点都有所不同，因此底物表面积的变化很可能导致物种组成发生变化，从而可能改变水生食物网的结构和生态过程。