LACLAIRE: UPLAND TEMPORARY POND VEGETATION IN FLORIDA


contributed to its low species richness and diversity due to domination of the pond
by a few obligate wetland species. In contrast, the ANF ponds were flooded only
along short lengths of the vegetation transects. The higher species richness and
diversity in ANF ponds was a reflection of the more variable moisture regime and,
thus, greater habitat complexity. The highest species richness and diversity, and
second highest level of evenness, were found in OS, which had been dry for 4
months when the vegetation was sampled.
 Clarification of this pattern is possible when co-dominant species and their
corresponding wetland indicator status are considered. In DP, the second and third
ranked most abundant vegetative cover along the transect represented species that
were either facultative upland or upland associated. In WE- 1, however, all three
of the co-dominant species were obligate wetland plants. The co-dominant species
in OS were a mix of obligate and facultative wetland species. The high species
richness and diversity in OS resulted from germination and growth of species
adapted to the drawdown cycle of temporary ponds. Mud exposed after the pond
dried was colonized rapidly, and at the time of sampling many of these plants had
set seed. When OS was visited 6 months later, the pond center was devoid of live
above-ground vegetation (LaClaire unpubl. data). The plants had senesced and
already were undergoing rapid decomposition.
 A comparison of species richness in BP and GP between the first and second
vegetation sampling adds further insight. The number of species in the first
sampling compared to the second sampling was 13 to 10 in BP and 15 to 17 in GP.
There was a drop in diversity, as indicated by H', for both ponds even though
species richness for GP increased. The apparent discrepancy in H' for GP can be
explained by comparing the average percent of live vegetation versus dead
vegetation occurring in quadrats in the two different years. In 1989, live
vegetation averaged 124% cover and dead vegetation averaged 31%. Greater than
100% cover in GP (1989) indicated the presence of layering in the quadrats,
another important aspect of species diversity. In 1990, live vegetation decreased to
63% of the total cover and dead vegetation increased to 53%. Even though species
richness increased, the total cover represented by these species decreased by almost
50%.


 CONCLUSIONS

 Composition and Structure of Temporary Pond Basin Vegetation


 A total of 112 vascular plant species were identified in the study ponds. Of
 these, only Panicum hemitomon was found in every pond sampled. Though species
 composition of individual ponds tended to be dissimilar, the species represented
 components of a pattern of zonation that was consistent between ponds. Hydrology