Document Type

Article

Version Deposited

Published Version

Publication Date

4-10-2018

Publication Title

Journal of Freshwater Ecology

DOI

10.1080/02705060.2018.1435429

Abstract

Food web studies commonly ignore individual variation within a population and variation in the environment and assume these factors have insignificant effects on community dynamics relative to interspecific interactions. However, variation in body sizes within a population (size structure) and the physical structure of habitats (habitat complexity) can both affect interspecific interactions independently, with possible interactive effects. Using experimental mesocosms, we examined effects of predator size structure and habitat complexity on predation by two common predators in fishless ponds: larval aquatic beetles (Cybister fimbriolatus) and larval dragonflies (Anax junius). Cannibalism, intraguild predation, and predation on shared prey were measured at two levels of habitat complexity crossed with six size-structured pairs of predators. We found that highly complex habitats sustain a higher prey density because prey can take refuge from predators. Additionally, size structure had direct (size better predicted predation rate than did species identity) and indirect (IGP and cannibalism lowered predation rates) effects on consumptive interactions, which changed the composition and density of the predator guild. The identified size- and habitat-mediated mechanisms can change the frequencies of intraguild vs. interguild predation (a balance important in determining top–down control of predators), and therefore we argue that these sources of heterogeneity should be included in community ecology studies where possible.

Comments

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Published Citation

Shannon K. Carter, Darrell Vodopich & Patrick W. Crumrine (2018) Heterogeneity in body size and habitat complexity influence community structure, Journal of Freshwater Ecology, 33:1, 239-249, DOI: 10.1080/02705060.2018.1435429

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