TY - JOUR
T1 - Optimal exploitation of spatially distributed trophic resources and population stability
AU - Basset, Alberto
AU - Fedele, M.
AU - DeAngelis, D. L.
N1 - Funding Information:
A. Basset was supported by MURST (COFIN) and EEC (ENV4-CT97-0594) grants. M. Fedele was supported by a fellowship from the Università di Lecce and the Province of Lecce. D.L. DeAngelis was supported by the Università di Lecce and the Florida Caribbean Science Centre of the U.S. Geological Survey, Biological Resources Division. We thank two anonymous referees for their comments on an earlier draft of this manuscript.
PY - 2002/6/1
Y1 - 2002/6/1
N2 - 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.
AB - 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.
KW - Consumer-resource interactions
KW - Enrichment theory
KW - Optimal foraging
KW - Patch departure rules
KW - Spatially explicit individual-based model
UR - http://www.scopus.com/inward/record.url?scp=0036605967&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036605967&partnerID=8YFLogxK
U2 - 10.1016/S0304-3800(01)00490-2
DO - 10.1016/S0304-3800(01)00490-2
M3 - Article
AN - SCOPUS:0036605967
VL - 151
SP - 245
EP - 260
JO - Ecological Modelling
JF - Ecological Modelling
SN - 0304-3800
IS - 2-3
ER -