Consequences of body size variation among herbivores on the strength of plant-herbivore interactions in a seasonal environment
Authored by Ofer Ovadia, Heinrich zu Dohna, Ginger Booth, Oswald J Schmitz
Date Published: 2007
DOI: 10.1016/j.ecolmodel.2007.03.022
Sponsors:
United States National Science Foundation (NSF)
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Abstract
Classical theory in community ecology assumes that smaller-scale details
such as individual traits can be abstracted safely and that community
dynamics can be simply characterized in terms of net changes in
population densities. Here we use a mechanistic simulation model of a
three-level food web to explore the effect of initial body size
variation among herbivores on final plant abundance resulting from a
non-linear relationship between population demography and body size. We
show that initial herbivore body size variation has a negative effect on
their survival and consequently a positive effect on the final plant
biomass. We then use trait distribution, in combination with body
size-survival and body size-fitness curves estimated through
simulations, to generate predictions for comparison with observed food
web effects. We show that, owing to frequency-dependence, our ability to
predict herbivore population dynamics is limited. However, at the
community-level, this frequency-dependence, as well as changes in
herbivore population size, can be abstracted safely and the strength of
plant-herbivore interactions can be simply predicted from initial body
size distribution in combination with the survival curve. our findings
suggest a need to revisit classical theory in community ecology. Doing
so will require the mechanistic study of population demography and
experimental testing of the effect of trait variation on community
dynamics. (c) 2007 Elsevier B.V. All rights reserved.
Tags
Competition
Individual-based model
behavior
Dynamics
Predator
Variability
Population
regulation
Relevant organizational scale
Life-histories
Mortality patterns