Harvesting discrete nonlinear age and stage structured populations

摘要: A natural extension of age structured Leslie matrix models is to replace classes with stage and assume that, in each time period, the transition from one class next incomplete; that is, diagonal terms appear matrix. This approach particularly useful resource systems where size more easily measured than age. In this linear setting, properties are known; these have been applied analysis population problems. applicable setting reproduction, survival, parameters model density dependent. The behavior such determined by form dependence. Here, we focus on which depend value an aggregated variable, defined be weighted sum number individuals class. forestry models, for example, variable may represent a basal area index; fisheries it spawning stock biomass. Current nonlinear stock-recruitment special case considered here. Certain results apply can extended broader models. particular, questions addressed relate minimum need harvested obtain maximum sustainable yield policies managing resources under nonequilibrium stochastic conditions. Application problems fisheries, forestry, pest, wildlife management also discussed.