Sun Zepeng
(International Institute for Applied Systems Analysis, Laxenburg and
Institute for Biodiversity Ecosystem Dynamics, University of Amsterdam)

A stage-structured consumer-resource model with discrete reproduction
and ontogenetic niche shifts

Absztrakt:
In classic Lotka-Volterra consumer-resource models only the reproduction of adults are assumed to be resource-dependent. However, the maturation of juveniles can also be resource-dependent as well. Taken into account a resource-dependent maturation rate of juveniles the model can probably have two states: reproduction controlled state when the adults are limited by their reource and development controlled state when the juveniles are limited. In this talk I will present a stage-structured consumer-resource biomass model with discrete reproduction and ontogenetic niche shifts. After being scaled, the model is governed by several parameters: the varying availabilities of two resources and the degree of ontogenetic niche shifts can lead to alternative stable states, which have also been observed in continuous-time models; the incerasing mortality rate of consumer population can lead to total consumer biomass overcompensation and Allee effect, which can only occur in the semi-dicsrete model. All of these results show that both the discrete reproduction and the ontogenetic niche shifts give rise to very different dynamics from the exising models.