CAREER: How Temporal Fluctuations Alter Indirect Interactions in Duckweed-based Communities and its Integration with a Student Report Exchange

食物网反映了物种之间的相互作用以及它们所吃的资源，通常是其他物种。食物网中的直接相互作用，即捕食者和猎物之间的直接相互作用，在决定群落中物种动态方面起着关键作用。通过中间物种的影响产生的间接相互作用可能不会立即显现，但可能与直接相互作用一样重要。气候模式预测，许多地区的环境变异性可能会增加，例如，由于强烈风暴事件和干旱的频率增加。将通过开发和测试食物网模型来研究环境变化对食物网中间接相互作用重要性的影响。食物网理论的实验测试将以浮萍为基础的社区进行。浮萍是一种小型、漂浮的水生植物，群落成员包括以浮萍为食的昆虫和这些昆虫的捕食者。温度的变化会引起环境的波动。通过使用浮萍群落来完善一般理论，将有助于加强对环境波动如何改变其他不容易操纵的系统的理解。本研究的广泛影响将包括在不同的小学教室中进行分布式实验设计，其中每个教室将是一个基于浮萍的研究项目的环境复制。此外，学生在小学和大学阶段设计的浮萍项目将通过互联网数据库交换，以扩大学生参与同伴交换，以探究为基础的方法来学习科学。

Food webs reflect the interactions among species and the resources that they are eating, typically other species. Direct interactions in food webs, those between a consumer and its prey, play key roles in determining the dynamics of species in a community. Indirect interactions, resulting from impacts through intermediary species, may not be immediately apparent but may be as important as direct interactions. Climate models predict that environmental variability may increase in many areas due to, for example, a greater frequency of intense storm events and droughts. The impact of increased environmental variability on the importance of indirect interactions in food webs will be studied by developing and testing food web models. Experimental tests of food web theory will be conducted using a duckweed-based community. Duckweeds are small, floating, aquatic plants, and community members include insects that eat duckweed and predators of those insects. Environmental fluctuations will be created by varying temperatures. Refining general theory through the use of the duckweed communities will provide enhanced understanding of how environmental fluctuations might alter other systems of interest which cannot be so easily manipulated.The broader impacts of this study will include a distributed experimental design among diverse elementary school classrooms in which each classroom will be an environmental replicate in a duckweed-based research project. In addition, student-designed duckweed projects at the elementary level and at the college level will be exchanged via an internet database to expand students' participation in a peer-exchange, inquiry-based approach to learning the science.