James S. Borrell

Habitat fragmentation represents an unprecedented threat to global biodiversity. Understanding the range at which individuals and populations can become reproductively isolated is vital to ecosystem management and the maintenance of genetic diversity. Here, I demonstrate an improved rapid assessment protocol for empirically measuring the settling velocity of pollen. I find significant differences in pollen settling velocity between species, suggesting different dispersal distances and population structures. It is also found that Stokes' law is a reasonable theoretical predictor of pollen settling velocity in many cases. These findings predict that plant genetic connectivity is spatially localized, raisings concerns for highly fragmented populations. This method should provide a means of rapidly assessing species and populations at increased risk of erosion to genetic diversity.