Spatial Heterogeneity, Not Visitation Bias, Dominates Variation in Herbivory

Authors

Kate L. Bradley, University of Nebraska - LincolnFollow
Ellen I. Damschen, North Carolina State UniversityFollow
Lauren M. Young, University of Nebraska - Lincoln
Daniel Kuefler, North Carolina State University
Sarah Went, University of Nebraska - Lincoln
Galen Wray, University of Nebraska - Lincoln
Nick M. Haddad, North Carolina State University
Johannes M. H. Knops, University of Nebraska - LincolnFollow
Svata M. Louda, University of Nebraska - LincolnFollow

Document Type

Article

Date of this Version

8-2003

Comments

Published in Ecology, 84(8), 2003, pp. 2214–2221. Copyright (c) 2003 by the Ecological Society of America. Used by permission.

Abstract

Experiments in ecology can have unintended side effects. Recently, it has been suggested that the act of visiting a plant, inherent to studying herbivory, may alter plant performance and interactions. To evaluate the generality of this inference, we examined plant performance and herbivory on 14 plant species in three geographic regions. Visitation did not significantly affect any of the variables that we measured, including leaf damage, height, biomass, or survivorship, for any species. However, rates of herbivory varied significantly among sites and regions. Thus, our data do not support the generality of visitation impacting estimates of herbivory. We propose that future studies of herbivory will gain more by evaluating spatial heterogeneity in interaction outcomes than by quantifying possible experimenter-caused variation.