%0 Journal Article
%T Troublesome toxins: time to re-think plant-herbivore interactions in vertebrate ecology
%A Robert K Swihart
%A Donald L DeAngelis
%A Zhilan Feng
%A John P Bryant
%J BMC Ecology
%D 2009
%I BioMed Central
%R 10.1186/1472-6785-9-5
%X By definition herbivores depend on plants to survive. The need to obtain suitable food in sufficient amounts drives innumerable herbivore behaviors; for example, movement decisions often are related to the distribution and abundance of plant resources [1]. By the same token, herbivores can exert strong effects on plant growth, survival, and population size by virtue of their feeding habits. Plant demographic effects are especially severe during cyclical peaks or irruptions in herbivore populations [2,3]. Moreover, the ecological effects of herbivores can extend beyond populations. Differential foraging among species can affect outcomes of competition, facilitate invasion of extant communities, and alter patterns of plant succession, diversity, and dominance [4-6].When focusing on optimal diet choice by herbivores, ecologists traditionally have relied on linear programming or linear dynamic programming methods [7,8]. Given a choice of two or more non-equivalent food types, these methods solve for optimal diet composition subject to constraints imposed by daily energy requirements, feeding time, digestive capacity, or nutrient requirements. Linear programming appears to provide reasonable predictions of diet composition for many species [9]. However, it does not address population-level dynamics of herbivores and plants.Consumer-resource interactions at the population level can be modeled using equations that relate the rate of resource intake by a consumer to resource abundance [10]. These so-called "functional-response" models link herbivore behavior and plant characteristics to population- and community-level consequences. In these models, upper limits to rates of consumption by herbivores are determined, either implicitly or analytically, by combining mechanical factors such as bite size and rate with plant quantity [11-13].A problem with conventional plant-herbivore models is their failure to incorporate factors related to plant quality into decelerating function
%U http://www.biomedcentral.com/1472-6785/9/5