global climate change, mangroves, Brazilian pepper, invasive, modeling
Mangrove ecosystems are among the world's most endangered biomes; nearly one-half of the overall coverage is threatened by human activity, invasive species, and global climate change. Mangroves play an important ecosystem role through detrital production and by providing: fisheries and wildlife nursery habitat, shoreline protection, a sink for nutrients, carbon, and sediment. In addition to human activity, the Florida mangroves (Avicennia germinans, Laguncularia racemosa, and Rhizophora mangle) are being threatened by the invasive Brazilian pepper (Schinus terebinthifolius). This study was performed along a 261 km stretch of the east coast of Florida from Sebastian Inlet to the northern extent of mangroves, near St. Augustine. It entailed two parts. The first examined the phenology and leafing rates of the four species and attempted to find if there was a relationship between growth and latitude or temperature. Although a correlation between peaks in temperature and phenology was observed for all species, no leafing pattern could be discerned. In terms of mangrove growth for branch diameter, a logarithmic model (y=a + b·log [Initial diameter]) best fitted the data for R. mangle and L. racemosa but neither latitude nor temperature appeared to be important. However, S. terebinthifolius' and A. germinans's branch diameter growth were best represented by a logarithmic model (y=a + b·log [Initial diameter] + c·log x2) that incorporated temperature and latitudinal respectively. In the second part, a simulation model was developed to focus on understanding the relationships between establishment and competition among the three mangrove species and the invading S. terebinthifolius. This model was run under various invasion and/or climate change scenarios to determine possible outcomes under global climate change with or without the presence of S. terebinthifolius. Conclusions were drawn that under all scenarios of invasion, other than sea level rise as part of global climate change, S. terebinthifolius would dominate the landscape if allowed to invade and establish in areas in which it is not currently present although the amount of this response is dependent on the S. terebinthifolius response curves.
Master of Science (M.S.)
College of Sciences
Length of Campus-only Access
Masters Thesis (Open Access)
Leitholf, Susan, "Assessing And Modeling Mangrove Forest Dynamics Along The Temperate-subtropical Ecotone In Eastern Florida" (2008). Electronic Theses and Dissertations. 3451.