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

水质和渔业资源依赖于淡水湖内物种相互作用的动态，但人们对温度升高（25摄氏度）以及食物丰富程度如何影响水生物种的相互作用知之甚少。本研究将探索水温升高（高达30℃）和食物丰度对浮游生物食物网中物种相互作用的相互作用。这三个营养级别的食物网包括一个初级生产者，2个甲壳类食草动物和一个捕食者，每一个都可以很容易地在实验室培养或维持。温度、食物丰度和这些条件的相互作用的影响将通过对前两个营养水平的成员进行的一系列单物种和双物种实验来评估。在不同的温度/食物丰度处理下，评估初级生产者的种群生长率、每种食草动物造成的损失率以及每种食草动物的繁殖力和存活率。实验结果将用于参数化模拟模型，该模型将预测各种环境条件下物种相互作用的结果，随后的研究将测试这些预测，将模型扩展到包括3个营养水平，并研究枝海食草动物在响应热选择压力时的进化速度。结果将有助于1)对温度升高的生物评估，2)建立一个模型食物网来评估环境对物种动态的影响，以及3)允许评估环境压力下群落中高阶相互作用的相对量级。

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.