Print PageUnder projections of anthropogenic change, suitable habitat for many organisms will become increasingly fragmented and environmental variation will likely increase. Such changes can make some species’ preferred habitat less suitable, or more difficult to colonize. Plant species which are adapted for dispersal have a means of accessing new habitat. However, over evolutionary time, environmental heterogeneity can act as a selective pressure favoring individuals that disperse or retain offspring depending on environmental conditions. Rapid habitat degradation or loss may alter the proportion of offspring surviving dispersal, and thus the population growth rates of these species. Similarly, the threat posed by weedy species may also change due to habitat alterations. Here, we develop metapopulation matrix models to examine how different environmentally-dependent dispersal strategies influence population growth rates under a range of habitat loss and degradation scenarios.
Results/Conclusions
As expected, we find that habitat degradation reduces population growth rates. However, we find that species’ dispersal strategies have a strong influence on their vulnerability to habitat loss. Interestingly, populations with similar life histories but different population growth rates differ in their response to habitat loss. Populations near replacement (with a growth rate near 1) are more threatened by population decline due to habitat loss, whereas rapidly growing populations are more sensitive to the same habitat losses. Given increasing anthropogenic habitat changes, these findings will help conservation planners better understand how to incorporate species’ dispersal strategies into expectations for future population viability.
