Tropical Forest Community Ecology

Testing Explanations for Species Diversity using FDPs 109

Distance (m)

0 5 10 15 20 25 30

No. of seedlings produced per 30 cm dbh parent

0

1

2

3

4

5

6

Density dependence

ignored

Density dependence

included

Tabebuia heterophylla

Casearia arborea

Distance (m)

0 5 10 15 20 25 30

No. of seedlings produced per 30 cm dbh parent

0

10

20

30

40

Density dependence

ignored

Density dependence

included

Figure 7.3 The shape of seedling dispersal curves for two species in the Luquillo plot (Uriarteet al. 2005b). The
continuous line represents the model that includes density dependence prior to any effects of density on seedling
mortality (i.e., as if no seedling had died from density-dependent effects). The dotted line represents a model that does
not include density-dependent effects (i.e., as if the effect were ignored).

that some tree species grow best in different-
sized gaps or under different light levels (Brokaw
1987, Agyemanet al. 1999), it is not clear
the degree to which this influences forest-wide
community composition, and the degree of gap

specialization may depend on the species’ func-

tional grou p(Schnitzer and Carson 2001). Sev-

eral studies have addressed ga pde pendence in

woody species in the BCI FDP. Weldenet al. (1991)

analyzed the recruitment, growth, and survival