Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references.

Thesis (doctoral)--Universität Bonn, 2007. / Includes bibliographical references (leaves 125-135). Also available via the internet.

Thesis (Ph. D.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 284-308).

Thesis (M. Phil.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 85-107).

published_or_final_version / Ecology and Biodiversity / Doctoral / Doctor of Philosophy

Ammonia/ammonium-oxidizing prokaryotes (AOPs) play a crucial role in nitrogen transformation in the natural ecosystems including mangrove wetlands. The objectives of the present study were to investigate the spatial and temporal distribution of AOPs in the mangrove wetland sediments in subtropical Hong Kong and their ecophysiology. When AOP communities and abundances in a natural coastal mangrove wetland and a constructed freshwater wetland were compared, the constructed freshwater wetland contained a broader range of phylotypes, higher diversity, more complex community structures, and more uneven abundances of AOPs than the mangrove wetland. Typha angustifolia affected the community structures of all AOPs and enhanced their abundances in the rhizosphere. Both Phragmites australis and Cyperus malaccensis showed some effects on the community structures of ammonia-oxidizing bacteria (AOB), but little effects on those of anaerobic ammonium oxidizing (anammox) bacteria or ammonia-oxidizing archaea (AOA). Kandelia obovata had no detectable effect on any group of the AOPs due to their smaller size. AOPs in oxic and anoxic sediments of a protected mangrove wetland were investigated in both winter and summer. Seasonality had little effect on community structure and abundance of anammox bacteria. AOA community structures were stable between the two seasons, but AOA abundance was significantly higher in winter than summer. The community structures of AOB were different between winter and summer, but the abundance in winter was apparently higher than that in summer. Sediment type had a noticeable influence on community structure and abundance of anammox bacteria. No apparent difference in AOA community structures between the different types of sediments in winter was observed, but the oxic sediments showed obviously different AOA community structures from anoxic sediments in summer. Sediment type had little effect on AOB community structures, but AOB abundance in oxic sediments was obviously lower than anoxic ones in both seasons. Addition of acetate or leaf litter into sediment inhibited the growth of anammox bacteria in laboratory incubation. The inhibition of anammox bacteria by acetate was more pronounced than by leaves. Acetate and leaf litter did not affect AOA community structures, but promoted their growth. Both acetate and leaf litter affected the AOB community structures and promoted their growth in the early phase of the incubation. The promoting effects by leaf litter were more obvious than by acetate. Allylthiourea effectively inhibited the growth of both AOA and AOB in laboratory incubation, but only slightly for anammox bacteria. Acidic condition altered AOB community structure, but affected anammox bacteria and AOA slightly. Alkaline condition strongly affected community structures of anammox bacteria and AOA, but slightly for AOB. Alkaline condition inhibited the growth of anammox bacteria, but promoted AOA and AOB slightly. Increase in salinity resulted in higher diversity of anammox bacteria, and AOA and AOB might have species specific preference for salinity. High salinity promoted anammox bacteria growth; inhibited AOA for 5-10 days, but promoted them afterward; and promoted AOB. Totally, this study revealed new and specific information on the spatial and temporal distribution of AOPs in mangrove wetland and factors affecting their ecophysiology. / published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Ecology and Evolution." Includes bibliographical references (p. 138-149).

Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references. / Also available by subscription via World Wide Web / xv, 252 leaves, bound ill., map 29 cm

No description available.

South Australian mangroves consist of only one single species Avicennia marina (Fosk.) Vierh.var australasica (Walp) Moldenke, 1960. They are distributed discontinuously within St. Vincent Gulf and Spencer Gulf and provide significant valuable habitat both in economical and ecological terms. The Fisheries Act 1971-1982 protected the existence of mangroves and the Harbour Act 1936-1981 controlled removal of mangrove areas in coastal development. To date very few ecological studies have been conducted in the South Australian mangroves, particularly on the infaunal organisms that have an important role in maintaining the ecological dynamic within the estuaries systems. As this is the first study on infaunal mangrove communities in the inverse estuaries of South Australia, there was no prior data for ecological comparison. The study was conducted at three mangroves location (Garden Island, Middle Beach and Saint Kilda) close to Adelaide in May 2000 and 2001. Overall the study has reported that the infaunal mangrove assemblages of South Australian mangroves were comparable to other temperate mangroves. The infaunal communities were characterised by lower diversity and abundance compared to the tropical or subtropical mangroves. The infaunal zonation related to the tidal gradient and habitat variation was detected. Most infauna organisms occupied the surface layers and substantially decreased towards the deeper layers. The study also suggested that sediment structure of mangrove systems were complex and infaunal communities responded differently to the change of environmental conditions both in small scale and larger scale. Thus, assessing the infaunal communities structure in mangrove systems should be based on ecological characteristics rather than geographical positions. The examination of dominant polychaetes families showed that different species have different responses to the environmental cues within mangrove systems. The study did not find that any polychaete species was restricted to mangroves only as they all were also found in the habitat adjacent mangrove forest. / Thesis (Ph.D.)--School of Earth and Environmental Sciences, 2003.