Thesis (M. Env. St.)--University of Adelaide, 1984. / Includes bibliographical references (leaves 273-308).

Thesis (M. Sc.) (Hons) -- University of Western Sydney, 2003. / "Submitted in accordance with guidelines for the Degree of Master of Science (Hons), College of Science, Technology and the Environment, University of Western Sydney, Hawkesbury, Richmond NSW, Australia, March 2003." Includes bibliography : leaves 229 - 254, and appendices.

Thesis (MAppSc) -- Auckland University of Technology, 2004. / Also held in print (214 leaves, 30 cm.) in Wellesley Theses Collection (T 577.698 SOL)

Thesis (Ph.D.) -- James Cook University, 2003. / Typescript (photocopy) Bibliography: leaves 214-238.

Thesis (Ph. D.)--Adelaide University, 2003. / Title from PDF title page (viewed on May 1, 2005). Includes bibliographical references (p. 135-152).

Thesis (Ph.D.) - University of Queensland, 2004. / Includes bibliography.

Mangroves in South Africa are prone to anthropogenic pressures such as browsing and trampling by livestock and by natural disturbances such as drought and floods. These mangroves exist at one of the most southerly limits in the world providing a unique opportunity to study recovery and resilience to change. This study used long term data at three South African study sites located in the subtropical (St Lucia Estuary) and warm temperate regions (Nxaxo and Kobonqaba estuaries) to compare mangrove growth rate, population structure and responses to disturbance. The first objective was investigated at St Lucia Estuary where site specific or microhabitat differences were measured to assess the influence of these on mangrove growth and population structure. It was suggested that site - specific variability would ensure mangrove survival and analysis showed that seedlings were present at different sites in different years. There was always some recruitment but often little survival to the next size class. Over time seedling numbers were quite variable and self – thinning of adults was evident. The second objective was to identify the environmental factors influencing population density and growth. Results showed that sediment moisture and salinity influenced seedling and adult density due to fluctuations in estuary water level. Mangrove growth rates for Avicennia marina in terms of height was faster (40 – 75 cm yr-1 ) at Site 1 where conditions were waterlogged and moderately saline and slower (5 – 25 cm yr1 ) in dry and hypersaline conditions at Site 4. Overall mangroves at St Lucia have shown persistence through drought and fluctuations in environmental conditions however resilience may be hindered at sites that are subjected to partially flooding and prolonged waterlogging. The second site was Nxaxo Estuary in the Eastern Cape where cattle exclusion plots (nonbrowsed) and control plots (browsed) were used to assess the recovery of A. marina trees from cattle browsing. Trees in the browsed plots showed no vertical growth while trees in the non-browsed plots grew significantly faster (5.4 ± 0.5 cm yr-1). When cattle were prevented from entering the mangrove area, the trees recovered fairly quickly and within 3 years growth was similar in both the non – browsed (17.9 ± 3.2 cm yr -1) and browsed plots (18 ± 1.6 cm yr -1). Lastly, mangrove recovery was investigated at Kobonqaba Estuary where long-term closure of the mouth to the sea resulted in high water levels, inundation of pneumatophores and die-back of the majority of the mangroves. This study measured the recovery of the mangroves by assessing changes in vegetation cover and sediment characteristics along transects. High initial porewater nutrient concentrations promoted salt marsh growth and plants increased average cover from 0% in 2011 to 18.9% (2013) and 50% in 2015. The total number of A. marina individuals increased from only seven to 27 individuals over four years. Salt marsh competition and facilitation will likely influence mangrove recovery in the future. Overall it was concluded that when a short term pressure (cattle browsing) is alleviated, mangrove forests even at warm temperate sites are able to recovery rapidly by increasing growth and seedling establishment. However, mangroves in the subtropical sites show more resilience and recovery potential to long term pressures such as fluctuating environmental conditions because of faster growth rates.

Sphaeroma terebrans, is an ecological engineer that can significantly modify the habitat of free-hanging aerial prop roots of Rhizophora mangle. The wood-boring isopod extensively burrows into red mangrove aerial prop roots for habitat and protection from desiccation and access to phytoplankton. However, the burrows created have major consequences on the mangrove habitat and aerial root inhabitants. It has been suggested that sessile species residing in aerial root communities can either encourage or discourage colonization by S. terebrans. Abiotic factors can affect the distribution and abundance of mangrove forest and are the same factors which determine the composition and abundance of organisms living on the roots. Surveys indicated that burrowing damage was found predominately in the first 20 cm of the root tip. Exploratory Structural Equation Modeling (SEM) was used to test multivariate hypothesized models looking at habitat relationships with S. terebrans in aerial root communities. Temperature and dissolved oxygen were shown to be important drivers in affecting submerged root length of aerial roots. Ultimately, the indirect effects between these parameters proved to be stronger in influencing the barnacle – isopod association, which causes direct negative effects on submerged root length. Colonial tunicates showed weak effects in masking aerial roots from the damaging barnacle – isopod association. Chlorophyll a was used as a proxy for phytoplankton biomass and proved to be less influential than habitat protection for S. terebrans. Results highlight the need for experimentation in addition to modeling in order to determine the mechanisms influencing aerial root community inhabitants and further effects on the habitat. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

The Last Glacial Maximum (LGM) was a period of massive range contraction for numerous taxa, including the water-dispersed mangrove species, Rhizophora mangle L. Following the LGM, R. mangle expanded poleward via propagule transport by ocean currents. In this study, we use microsatellite loci to characterize the genetic structure of nine R. mangle populations and compare potential expansion pathways that resulted in the colonization of the Florida peninsula and Caribbean islands. Results show comparatively greater genetic connectivity between the Caribbean mainland and Florida, a similar pattern between West Africa and Caribbean islands, and substantial admixture on the island of San Salvador, the Bahamas. We conclude that Florida and Caribbean island R. mangle populations were likely recolonized via different expansion pathways. Estimates of recent migration rates are low and populations are structured into three regions (Caribbean mainland, Caribbean islands, Florida). These findings provide insight for future management and conservation initiatives. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

published_or_final_version / Ecology and Biodiversity / Master / Master of Philosophy