Document Type
Article
Publication Title
Ecology
Publication Date
2-2011
Volume
92
Issue
2
Disciplines
Biology | Life Sciences
Abstract
The shrub Iva frutescens, which occupies the terrestrial border of U.S. Atlantic Coast salt marshes, supports a food web that varies strongly across latitude. We tested whether latitudinal variation in plant quality (higher at high latitudes), consumption by omnivores (a crab, present only at low latitudes), consumption by mesopredators (ladybugs, present at all latitudes), or the life history stage of an herbivorous beetle could explain continental-scale field patterns of herbivore density. In a mesocosm experiment, crabs exerted strong top-down control on herbivorous beetles, ladybugs exerted strong top-down control on aphids, and both predators benefited plants through trophic cascades. Latitude of plant origin had no effect on consumers. Herbivorous beetle density was greater if mesocosms were stocked with beetle adults rather than larvae, and aphid densities were reduced in the “adult beetle” treatment. Treatment combinations representing high and low latitudes produced patterns of herbivore density similar to those in the field. We conclude that latitudinal variation in plant quality is less important than latitudinal variation in top consumers and competition in mediating food web structure. Climate may also play a strong role in structuring high-latitude salt marshes by limiting the number of herbivore generations per growing season and causing high overwintering mortality.
DOI
10.1890/10-0760.1
Rights
Copyright 2011 by the Ecological Society of America. L. B. Marczak, C.-K. Ho, K. Więski, H. Vu, R. F. Denno, and S. C. Pennings 2011. Latitudinal variation in top-down and bottom-up control of a salt marsh food web. Ecology 92:276–281. http://dx.doi.org/10.1890/10-0760.1
Recommended Citation
Marczak, Laurie B.; Ho, C.-K.; Wieski, K.; Vu, H.; Denno, R. F.; and Pennings, S. C., "Latitudinal Variation in Top-Down and Bottom-Up Control of a Salt Marsh Food Web" (2011). Biological Sciences Faculty Publications. 252.
https://scholarworks.umt.edu/biosci_pubs/252
Comments
Copyright 2011 by the Ecological Society of America. L. B. Marczak, C.-K. Ho, K. Więski, H. Vu, R. F. Denno, and S. C. Pennings 2011. Latitudinal variation in top-down and bottom-up control of a salt marsh food web. Ecology 92:276–281. http://dx.doi.org/10.1890/10-0760.1