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.
