A Theoretical Framework for Data Analysis of Wind Dispersal of Seeds and Pollen

We compared a variety of models for the analysis of data on the wind dispersal of seeds and pollen. Dispersal distances from a source depend upon such factors as settling velocity, height of release, wind speed and turbulence, and specific morphological adaptations for dispersal. The dispersal curve, which describes the frequency distribution of dispersal distances, usually shows its peak at some distance from a source and falls off with distance. We used the location of that peak as a measure of dispersal, and organized data in terms of the predictions of two models for the dynamics of advection and diffusion. These data are summarized in a seed dispersal diagram in which the modal distance normalized by the height of seed release is plotted against the mean with speed normalized by the falling speed of seeds. Data from 15 studies were used to compare actual dispersal relationships.