Input - Genetic Diversity in Establishing Plant Populations: Founder Number and Geometry - page 46

total number of eligible dispersal points increases as the average dispersal
distance units (again, as calculated above) increase: note that the increase
in points is a square function relative to increase in average dispersal
distance. We will return to these features of dispersal, since they will
become important in explaining patterns of genetic diversity retention
under different reintroduction scenarios.

350

A

280

210

140

70

0

0 100 200 300 400 500

MAXIMUM DISPERSAL D

1000000

B

800000

600000

400000

200000

0

0 67 134 201 268 335

MEAN DISPERSAL D

Fig. 4.1 NEWGARDEN dispersal distance conventions. A zygotic offspring (2n; e.g., a seed)
is dispersed a certain number of grid points away from its parent, or, the microgamete (e.g.,
pollen) is transported a certain number of grid points to the zygotic offspring-producing
parent from one of the eligible microgamete-producing individuals within a certain maximum
distance. The maximum distance of dispersal is D. A. The lower line depicts the mean dispersal
distance if dispersal can occur only along one line. The average dispersal distance will then
be D/2. The upper line is the average dispersal distance if D defi nes the borders of a square
around a central zygotic offspring-producing, or microgamete-receiving, parent (the square
includes ((2d)+1) 2 points, including the central parent). The average dispersal distance can
then be calculated as noted in the text. B. The total number of available dispersal points
grows geometrically (as a square of the maximum dispersal distance) as the mean dispersal
distance increases.