Heterogeneity in dynamic species abundance models: the selective effect of extinction processes.
There is often large variation in traits across the species of a community. In particular, variation in life history traits affecting population dynamics is likely to affect the species abundance distribution. Applying a dynamic and heterogeneous species abundance model we study how differences in extinction time for species in a community act as a force changing the distribution of dynamic parameters across species. This process may generate communities that are more heterogeneous then the heterogeneity measured as the species enter the community. Analytical results for some versions of the lognormal and gamma species abundance model are given as exemplifications of this process, together with stochastic simulations demonstrating the temporal changes in number of species and community heterogeneity through time.
Engen
Steinar
S
Department of Mathematical Sciences, Norwegian University for Science and Technology, N-7491, Trondheim, Norway. steinaen@math.ntnu.no
D000818:Animals; D003198:Computer Simulation; D017753:Ecosystem; D053476:Extinction, Biological; D008954:Models, Biological; D011157:Population Dynamics; D013269:Stochastic Processes