Affiliation:
1. Department of Ecology, Evolution, and Behavior University of Minnesota Saint Paul Minnesota USA
2. Agronomy Department University of Florida Gainesville Florida USA
3. Minnesota Department of Natural Resources Minnesota Biological Survey Saint Paul Minnesota USA
4. Department of Biology University of Florida Gainesville Florida USA
Abstract
AbstractFood has long been known to perform dual functions of nutrition and medicine, but mounting evidence suggests that complex host‐pathogen dynamics can emerge along continuous resource gradients. Empirical examples of nonmonotonic responses of infection with increasing host resources (e.g., low prevalence at low and high resource supply but high prevalence at intermediate resources) have been documented across the tree of life, but these dynamics, when observed, often are interpreted as nonintuitive, idiosyncratic features of pathogen and host biology. Here, by developing generalized versions of existing models of resource dependence for within‐ and among‐host infection dynamics, we provide a synthetic view of nonmonotonic infection dynamics. We demonstrate that where resources jointly impact two (or more) processes (e.g., growth, defense, transmission, mortality, predation), nonmonotonic infection dynamics, including alternative states, can emerge across a continuous resource supply gradient. We review the few empirical examples that concurrently measured resource effects on multiple rates and pair this with a wide range of examples in which resource dependence of multiple rates could generate nonmonotonic infection outcomes under realistic conditions. This review and generalized framework highlight the likely generality of such resource effects in natural systems and point to opportunities ripe for future empirical and theoretical work.
Funder
National Science Foundation
U.S. Department of Agriculture
University of Florida Foundation
Wageningen University and Research
Subject
Nature and Landscape Conservation,Ecology,Ecology, Evolution, Behavior and Systematics