Predator Regulation of Prey Biogeography: Daphnia and Planktonic Chrysophyte Algae

小行星9318402 这项研究将提供一个严格的测试捕食作为一个主要因素，在确定猎物的地理。PI的将测试的可能性，许多群体的藻类，如金藻鞭毛虫的地理分布，主要是强大的捕食者与食草浮游动物，水蚤相互作用的结果。浮游藻类的分布与湖泊生产力之间有很强的负相关性。虽然水蚤已被确定为湖泊食物网中占主导地位的草食动物，但以前没有强调它会影响湖泊中金藻的分布。替代假设，如藻类之间的竞争营养物质，也将被考虑。从这些假设的预测将与实验室和现场实验相结合，模拟藻类物种之间的竞争，并采样经验分布的藻类，水蚤，湖泊生产力进行测试。 这项研究是重要的，因为它将测试一个新的和重要的假设，关于物种的地理分布和丰富度的捕食者密度和栖息地生产力。由于一些藻类水华会导致水库水质变差，这些结果将对评估湖泊水质的生物因素具有重要意义。 ***

9318402 Sandgren This research will provide a rigorous test of predation as a primary factor in determining prey biogeography. The PI's will test the possibility that the biogeographical distribution of many groups of algae, such as chrysophyte flagellates, is primarily the result of strong predator-prey interactions with the herbivorous zooplankton, Daphnia. There is a strong negative correlation between the distribution of Chrysophyte algae and lake productivity. While Daphnia has been identified as a dominant herbivore in lake food webs, it has not been previously emphasized as affecting the distribution of chrysophytes among lakes. Alternative hypotheses, such as competition between algae for nutrients, will be considered, as well. Predictions from these hypotheses will be test with a combination of laboratory and field experiments, modeling competition among algae species, and sampling empirical distribution of algae, Daphnia, and lake productivity. %%% This research is important because it will test a novel and important hypothesis regarding the biogeographic distribution and abundance of species in response to predator densities and habitat productivity. Because some algal blooms can cause poor water quality in reservoirs, these results will have important implications for assessing the biotic factors that contribute to lake water quality. ***