Disproportionate Importance of Edge Habitat for Ecosystem Functoning in Deep Oligotrophic Lakes

stephanie E. Hampton, University of idaonsf Starter Grant(0528531), 2005 .人类活动极大地改变了湖岸的许多方面；特别是，肥料和污水中的营养物质会滋生讨厌的藻类，而树木的移除会减少阴影，也会减少掉到水面上的昆虫的数量，而这些昆虫会被湖上的动物吃掉。虽然湖岸可能是人类干扰的一个相对较小的湖泊区域，但这个近岸地区往往可能是鱼类和其他动物繁殖和觅食的最重要的栖息地。在这里，将通过检查湖泊动物和植物组织中天然存在的稳定同位素来评估近岸环境的重要性；碳同位素可以表明生长主要是由近岸还是开阔水域的食物资源支持，氮同位素与生物体在“食物链”中的位置有关。稳定同位素还可以帮助区分促进滋扰藻类生长的不同营养污染物，从而使管理人员可以更有效地进行监测和控制。早在湖泊其他部分受到污染之前，对海岸线的干扰就会影响生态系统的功能。管理人员越来越多地呼吁控制近岸污染，尽管局部干扰对整个湖泊的影响尚未得到很好的了解。这项研究将提供关于近岸环境在构建植物和动物群落中的作用的关键信息，并有助于优先考虑湖泊的管理和保护工作。

Disproportionate importance of edge habitat for ecosystem functioning in deep oligotrophic lakesStephanie E. Hampton, University of IdahoNSF Starter Grant (0528531), 3 August 2005Human activities greatly alter many aspects of lakeshores; in particular, nutrients from fertilizers and sewage can encourage nuisance algae, and tree removal can decrease shading as well as reduce the number of insects that fall to the water surface where they are eaten by lake animals. While the lakeshore may constitute a relatively tiny area of the lake disturbed by humans, this nearshore area frequently may be the most critical habitat for breeding and feeding by fish and other animals. Here the importance of nearshore environments will be evaluated through examination of naturally occurring stable isotopes in tissues from lake animals and plants; carbon isotopes can indicate whether growth is mainly supported by nearshore or open water food resources, and nitrogen isotopes relate to an organism's position in the "food chain". Stable isotopes can also help differentiate among different nutrient pollutants that fuel growth of nuisance algae, such that managers can more effectively target monitoring and control. Disturbance to the shoreline can affect ecosystem functioning long before the rest of the lake appears polluted. Managers increasingly call for controls on nearshore pollution, although lake-wide consequences of localized disturbances are not yet well understood. This research will provide critical information on the role of nearshore environments in structuring plant and animal communities and help prioritize management and conservation efforts in lakes.