ROW/RPG: How Do Elevated Temperatures Influence Food Web Interactions?

水质和渔业资源取决于淡水湖内物种间相互作用的动态变化，然而，关于温度升高(25摄氏度)以及食物丰富如何影响水生物种间的相互作用，人们知之甚少。这项研究将探索水温升高(高达30摄氏度)和食物丰度对浮游食物链模型中物种相互作用的交互影响。这三个营养级别的食物网包括一个初级生产者，两个甲壳类食草动物和一个捕食者，每个都可以很容易地在实验室培养或维护。温度、食物丰度和这些条件的相互作用的影响将通过在前两个营养级别的成员上进行的一系列单一和两个物种实验来评估。在不同的温度/食物丰度处理下，将评估初级生产者的种群增长率、每个食草动物物种造成的损失率以及每个食草动物的繁殖力和存活率。实验结果将被用来对模拟模型进行参数化，该模型将预测各种环境条件下物种相互作用的结果，后续研究将检验这些预测，将模型扩展到包括3个营养级别，并调查枝角类食草动物如何快速进化以响应热选择压力。结果将1)有助于对高温的生物评估，2)建立一个评估环境对物种动态影响的模型食物网，以及3)允许评估环境压力下群落中较高级别相互作用的相对大小。

Water quality and fisheries resources are dependent on the dynamics species interactions within fresh water lakes, yet little is known about how warmer temperatures (25 C), in conjunction with food abundance, affect interactions of aquatic species. This research will explore interactive effects of elevated water temperature, up to 30 C, and food abundance on species interactions in a model planktonic food web. This three trophic-level food web includes a primary producer, 2 crustacean grazers, and one predator, each can be easily cultured or maintained in the laboratory. Effects of temperature, food abundance, and interactions of these conditions will be evaluated using a series of single and two-species experiments performed on members of the first two trophic level. Populations growth rates of the primary producer, loss rates caused by each grazer species, and the fecundity and survival of each grazer will be evaluated in different temperature/food abundance treatments. Results of experiments will be used to parameterize a simulation model which will project the outcome of species interactions under a wide variety of environmental conditions, Subsequent research will test these predictions, extend the model to include 3 trophic levels, and investigate how rapidly cladoceran grazers evolve in response to thermal selection pressures. Results will 1) aid in biotic assessments of elevated temperature, 2) establish a model food web for evaluating environmental effects on species dynamics, and 3) allow evaluation of the relative magnitude of higher order interactions in communities that are environmentally stressed.