Niche and Neutral Processes Structuring A Damselfly Functional Group

Dartmouth College, Hanover NH

Investigators

Abstract

Ecological theory is generally built on the assumption that different species occupy different niches in the environment. This means that for species to live together they must do different things, and what is beneficial to one species is detrimental to another. However, a tremendous amount of empirical evidence suggests that many closely related species are also nearly identical to one another. This means that features of the ecological world may not be maintaining species in a system at all. More importantly, some species may be slowly being driven extinct at imperceptible rates by interactions with other species in the system. This alternative is known as 'ecological drift', a process whereby species' relative abundances change according to a random walk that is akin to random genetic drift. This proposal describes research to evaluate these alternatives in damselfly assemblages found in lakes with fish across eastern North America. This work combines regional investigations of 80 lakes to search for broad-scale patterns with critical field experiments that test the fundamental predictions that can discriminate niche from neutral processes. Our ability to construct sound biodiversity management and preservation strategies will critically depend on our understanding of the mechanisms promoting high diversity. The broader impacts of the proposed activity are to engage undergraduates in all components of the scientific research enterprise, and to foster science curriculum for our local K-5 elementary schools.