Range border formation in a world with increasing climatic variance

Authored by Hans Joachim Poethke, Alexander Kubisch

Date Published: 2011

Sponsors: German Research Foundation (Deutsche Forschungsgemeinschaft, DFG)

Platforms: No platforms listed

Model Documentation: Other Narrative

Model Code URLs: Model code not found

Abstract

Questions: How will a change in climatic conditions characterized by an increase in the variance of environmental conditions affect the distribution of species along spatial environmental gradients? How does the specific type of gradient influence their response? Features of the model: Spatially explicit individual-based simulation of a metapopulation. Logistic population growth and density-dependent emigration. Spatial gradients in habitat isolation, quality, and size. Ranges of the key variables: Environmental stochasticity was modelled as a variation of net reproductive rate (lambda). For a mean reproductive rate of lambda = 2, the standard deviation (sigma) was varied in the range of 0 to 3. Conclusions: When the range margin was predominantly determined by a lack of colonizers, ranges initially expanded with increasing environmental fluctuations, but contracted again when these fluctuations became too strong (sigma > 1). When extinction risk was more important for range formation, the initial expansion was damped or completely absent. When the climate changed too fast to allow for local adaptation of dispersal behaviour, the described patterns were less pronounced.

Tags

Evolution models Dynamics Density-dependent dispersal Rates Populations Expansion Species range Emigration Extremes