Metapopulation dynamics across gradients - the relation between colonization and extinction in shaping the range edge

摘要: We study the dynamics of a metapopulation in which rates colonization and/or extinction change along an environmental gradient. Spatially explicit simulations are applied to compare two cases: parent-dependent (PDC) rate is limited by production new individuals; offspring-dependent (ODC) it success establishment offspring. Thus, PDC depends on quality parent's site, while ODC dependent offspring's site. combine and spatially implicit model. steady-state distribution metapopulation, ask whether local densities occupied sites at each position x gradient could be predicted from c(x) e(x). This prediction not trivial, since connected, enabling flow individuals more favorable less sites. The results show that single parameter, c(x)/e(x), sufficient for prediction. Therefore, different species geographic regions can directly compared appropriate rescaling: choosing average lifetime occupancy, 1/e(x), time unit point permits generalizations about shape range edges, help predict boundary species' distribution. At PDC, rescaling possible: whole profile e(x) has taken into consideration. Nevertheless, gives good approximation when component does abruptly across space.