Meeting Abstract
P2.8 Friday, Jan. 4 Mangrove propagule predation: a test of the incomplete dominance hypothesis and restoration implications DONNELLY, M.J.*; WALTERS, L.J.; Univ. of Central Florida, Orlando; Univ. of Central Florida, Orlando mwtd@bellsouth.net
The incomplete dominance hypothesis states abundance of mangrove species is negatively correlated with propagule predation. Three mangrove species are native to Florida, Rhizophora mangle (red mangrove), Avicennia germinans (black mangrove), and Laguncularia racemosa (white mangrove). We evaluated propagule predation on these species in Mosquito Lagoon, FL by: 1) estimating the percent of propagules damaged before dispersal, 2) placing 25 propagules into replicate 1-m2 quadrats in the intertidal, mid-marsh, and ecotone zones to measure propagule damage after dispersal, and 3) surveying transects to determine densities of the mangroves in each zone. The percentage of pre-dispersal predation was not different among mangrove species, but the type of damage (punctures, bite marks, scrapes) varied by species. Within the quadrats, predation on R. mangle was significantly different between the three zones, with the lowest predation in the intertidal zone and the highest in the mid-marsh quadrats. The estimated density of R. mangle from the transect surveys was highest in the intertidal zone and supported the incomplete dominance hypothesis. Propagules of A. germinans and L. racemosa were not retained in the quadrats, however, estimates of density found A. germinans to be most abundant in the intertidal region, compared to L. racemosa, which was most abundant in the mid-marsh zone. Further research is needed to understand the role of seed predation on distribution and survival of these two species. In summary, survival of mangrove propagules is influenced by propagule predation before and after dispersal and this should be addressed when planning and evaluating mangrove restoration projects involving planting of propagules or seedlings.
