Light, Phosphorus, and Ecological Stoichiometry in Pelagic Communities

埃尔泽 9725878 生态学家越来越意识到构成生态系统食物网的有机体元素组成差异的根本重要性。 Elser是这个提议的PI，他是发展生态化学计量学领域的领导者之一。 该项目支持的工作将把联合收割机模拟调查与野外和人工围隔实验相结合，以研究光和营养物质供应对远洋生境水生群落组织的联合影响。 具体来说，它将测试不同的光照和营养条件是否可以通过改变主导相互作用的生态化学计量来将远洋群落转变为根本不同的状态。 建模研究将评估交替状态的可能性，其中一种状态由数量效应主导，例如低藻类生物量限制食草动物的生长，另一种状态由营养效应驱动，其中藻类食物质量差可能限制食草动物的生长。 模拟结果将在加拿大实验湖区进行的实地操作和日本京都大学新的最先进设施的人工围隔生态系统中进行测试。 实验将涉及操纵光和启动食草动物的条件，以测试这些替代生态系统状态的模型预测。 这项工作将有助于了解人口动态与生态系统功能之间的相互关系。 它具有重要的理论和实践意义。

Elser 9725878 Ecologists have been increasingly aware of the fundamental importance of differences in the elemental composition of organisms that comprise the food webs of ecosystems. Elser, the PI on this proposal, has been one of the leaders in developing this field termed ecological stoichiometry. The work supported by this project will combine modeling investigations with experiments in field and artificial enclosures to examine the joint effects of light and nutrient availability on the organization of aquatic communities in pelagic habitats. Specifically it will test whether different light and nutrient conditions can shift pelagic communities into fundamentally different states by altering the ecological stoichiometry of dominant interactions. Modeling studies will evaluate the potential for alternate states in which one is dominated by quantity effects such as where low algal biomass limits growth by grazers and the alternate is driven by nutritional effects where poor algal food quality can limit grazer growth. Modeling results will be tested in field manipulations conducted at the Experimental Lakes Area in Canada and in artificial mesocosms at new, state-of-the-art facility at Kyoto University in Japan. Experiments will involve manipulations of light and starting grazer conditions to test predictions from the model on these alternate ecosystem states. This work will contribute to the understanding of the interface between population dynamics and ecosystem function. It has substantial theoretical and practical implications.