Optimal exploitation of spatially distributed trophic resources and population stability
Authored by Donald L DeAngelis, A Basset, M Fedele
Date Published: 2002
DOI: 10.1016/s0304-3800(01)00490-2
Sponsors:
Italian Ministries
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
The relationships between optimal foraging of individuals and population
stability are addressed by testing, with a spatially explicit model, the
effect of patch departure behaviour on individual energetics and
population stability. A factorial experimental design was used to
analyse the relevance of the behavioural factor in relation to three
factors that are known to affect individual energetics; i.e. resource
growth rate (RGR), assimilation efficiency (AE), and body size of
individuals. The factorial combination of these factors produced 432
cases, and 1000 replicate simulations were run for each case. Net energy
intake rates of the modelled consumers increased with increasing RGR, consumer AE, and consumer body size, as expected. Moreover, through
their patch departure behaviour, by selecting the resource level at
which they departed from the patch, individuals managed to substantially
increase their net energy intake rates. Population stability was also
affected by the behavioural factors and by the other factors, but with
highly non-linear responses. Whenever resources were limiting for the
consumers because of low RGR, large individual body size or low AE, population density at the equilibrium was directly related to the patch
departure behaviour; on the other hand, optimal patch departure
behaviour, which maximised the net energy intake at the individual
level, had a negative influence on population stability whenever
resource availability was high for the consumers. The consumer growth
rate (r) and numerical dynamics, as well as the spatial and temporal
fluctuations of resource density, which were the proximate causes of
population stability or instability, were affected by the behavioural
factor as strongly or even more strongly than by the others factors
considered here. Therefore, patch departure behaviour can act as a
feedback control of individual energetics, allowing consumers to
optimise a potential trade-off between short-term individual fitness and
long-term population stability. (C) 2002 Elsevier Science B.V. All
rights reserved.
Tags
models
Dynamics
Coexistence
Enrichment
Foraging behavior
Predator-prey interactions
Parus-major
Patch use
Food-chains
Departure