Simplifying a physiologically structured population model to a stage-structured biomass model.
2008 (English)In: Theoretical Population Biology, ISSN 0040-5809, E-ISSN 1096-0325, Vol. 73, no 1, 47-62 p.Article in journal (Refereed) Published
We formulate and analyze an archetypal consumer-resource model in terms of ordinary differential equations that consistently translates individual life history processes, in particular food-dependent growth in body size and stage-specific differences between juveniles and adults in resource use and mortality, to the population level. This stage-structured model is derived as an approximation to a physiologically structured population model, which accounts for a complete size-distribution of the consumer population and which is based on assumptions about the energy budget and size-dependent life history of individual consumers. The approximation ensures that under equilibrium conditions predictions of both models are completely identical. In addition we find that under non-equilibrium conditions the stage-structured model gives rise to dynamics that closely approximate the dynamics exhibited by the size-structured model, as long as adult consumers are superior foragers than juveniles with a higher mass-specific ingestion rate. When the mass-specific intake rate of juvenile consumers is higher, the size-structured model exhibits single-generation cycles, in which a single cohort of consumers dominates population dynamics throughout its life time and the population composition varies over time between a dominance by juveniles and adults, respectively. The stage-structured model does not capture these dynamics because it incorporates a distributed time delay between the birth and maturation of an individual organism in contrast to the size-structured model, in which maturation is a discrete event in individual life history. We investigate model dynamics with both semi-chemostat and logistic resource growth.
Place, publisher, year, edition, pages
Elsevier Inc. , 2008. Vol. 73, no 1, 47-62 p.
Biomass, Body Size, Food, Humans, Models; Biological, Models; Statistical, Mortality, Population Dynamics, Reproduction
IdentifiersURN: urn:nbn:se:umu:diva-11449DOI: 10.1016/j.tpb.2007.09.004PubMedID: 18006030OAI: oai:DiVA.org:umu-11449DiVA: diva2:151120