Implications of Dispersal and Life History Strategies for the Persistence of Linyphiid Spider Populations

TL;DR

This study uses a stochastic model to assess how dispersal and life history traits affect the long-term persistence of Linyphiid spider populations in disturbed landscapes, emphasizing the importance of life history over dispersal.

Contribution

It introduces a stochastic population model that evaluates the relative importance of dispersal and life history traits for population persistence in heterogeneous environments.

Findings

Dispersal frequency has limited impact on extinction probability.

Mean birth and death rates are more influential than dispersal.

Landscape composition significantly affects population persistence.

Abstract

Linyphiid spiders have evolved the ability to disperse long distances by a process known as ballooning. It has been hypothesized that ballooning may allow populations to persist in the highly disturbed agricultural areas that the spiders prefer. In this study, I develop a stochastic population model to explore how the propensity for this type of long distance dispersal influences long term population persistence in a heterogeneous landscape where catastrophic mortality events are common. Analysis of this model indicates that although some dispersal does indeed decrease the probability of extinction of the population, the frequency of dispersal is only important in certain extremes. Instead, both the mean population birth and death rates, and the landscape composition, are much more important in determining the probability of extinction than the dispersal process. Thus, in order to develop effective conservation strategies for these spiders, better understanding of life history processes should be prioritized over an understanding of dispersal strategies.