Ecological benefits and toxicological consequences of flooding in river ecosystems

洪灾是一种自然事件，由于其对人的财产以及极端情况下对人的生命的负面影响，公众往往认为其具有一致的危害性。但洪水也可以通过影响生态系统服务间接造福人类。这项研究的目标是确定洪水对生活在河流中的鱼类和其他动物的好处和后果。它将使用一个模型生态系统--艾伯塔省落基山脉山脚下的一系列河狸池塘--以及萨斯喀彻温河中一个容易发生洪水的大型三角洲，来检验这样一个假设：与河流自由流动的部分相比，河流浅水泛滥地区的初级生产力更高，鱼产量更多、更大，食物链也更长。这些好处预计将被土壤释放的潜在有毒微量元素浓度更高以及洪水腐烂的有机物质所抵消。

Floods are natural events that are often perceived by the public as uniformly harmful because of their negative effects on human property and in extreme cases, human life. But floods can also indirectly benefit humans via their influence on ecosystem services. The goal of this research is to determine the benefits and consequences of flooding for fish and other animals that live in rivers. It will use a model ecosystem - a series of beaver ponds in the Rocky Mountain foothills of Alberta - and a large, flood-prone delta in the Saskatchewan River to test the hypothesis that shallow, flooded areas of the river have higher rates of primary productivity, produce more and larger fish and have longer food chains than free-flowing sections of the river. These benefits are expected to be offset by higher concentrations of potentially toxic trace elements that result from their liberation from soils and decaying organic matter by floodwaters.