PS 88-263
Hydrologic control of ground cover communities in cypress comes of west-central Florida
As human activities continue to alter the hydrology of wetland ecosystems, understanding the response of vegetation communities is becoming critically important. This study utilizes a historical plant database collected between 1977 and 2002 to characterize ground cover communities in geographically isolated cypress domes of west-central Florida. A Principal Components Ordination (PCO) was conducted on the most dominant ground cover species sampled during annual monitoring of meter squared ground cover plots in 19 natural, isolated cypress domes. Species groupings were compared to three common hydrologic parameters (maximum depth, average depth, and hydroperiod) observed one year prior to vegetation monitoring to describe where species are found hydrologically and those parameters most important in describing plant distributions.
Results/Conclusions
A total of 106 plant species were identified, with the 29 most common included in the analysis. Five distinct communities were identified by the PCO, with one group being quite large and the other four considerably smaller. The average annual hydroperiod for each PCO group identified was statistically different from one another (T-test, α=0.05), with considerable overlap in the average annual water depth and maximum depth present between groups. Hydroperiod averages between groups ranged between 80% and 9% inundation, while average annual depth ranged from 0.24m to 0.2m, and annual maximum depth ranging from 0.47m to 0.19m, respectively. Current restoration and management practices of wetlands often focus on restoring a maximum water depth in a wetland since this parameter is simple to establish and monitor using piezometers and outflow structures. This research shows that although water depth can be quite important, the composition of wetland plant communities is most closely correlated with the duration of inundation, and increasing water levels for a short period of time may not be sufficient to restore wetland habitats. Instead, management efforts should also focus heavily on restoring the hydroperiod of an impacted wetland.