Thesis (M. Sc.)--University of Hong Kong, 2006. / Also available in print.

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 73-74). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (November 14, 2006) Vita. Includes bibliographical references.

Thesis (M. Sc.)--University of Hong Kong, 2006.

The approach adopted in this thesis is essentially chronological. The first chapter aims to provide a fairly superficial survey of the development of European perceptions of the environment in the early phases of mercantilist expansion, before much in the way of colonial settlement was undertaken. It highlights the connections between expansion and changes in perception with regard to the symbolic importance of islands, botanic gardens and early state responses to timber shortage. It also draws attention to the importance of medical perceptions of the extra-European environment. In the second chapter a comparison is drawn between Dutch and English approaches to the tropical environment in the early years of expansion. Considerable space is devoted to the case of St Helena. This is because it was the first location in which European colonists first acquired a notion of the full environmental implications of their rule and for which detailed documentary evidence is available. The story of the developing ecological crisis on St Helena emphasises how inadequate European precedents were in the encounter between the early colonial state and the tropical environment. It demonstrates, too, the early divergence in perceptions between colonists and the metropolitan power. Early attempts at counteracting the process of ecological deterioration on St Helena underlined the contradictions between the European image of the tropical island and the reality of capital investment in plantation agriculture and 'improvement'. The experience of St Helena was also important in a longer-term way. Many scientists important in the later development of conservation ideas in other parts of the world were specifically influenced by their knowledge of the problematic history of land-use on St Helena and the attempts made there to impede ecological degradation. These included Alexander Beatson, J.R. Forster, Joseph Hooker, F.A. Dalzell and G.P. Marsh. In the third chapter much attention is devoted to the history of eighteenth century Mauritius, partly for comparative purposes and partly to emphasise the attitude of the French state to scientific information and its greater readiness to intervene in environmental matters. The development of an environmental consciousness on Mauritius was significant both as a phenomenon on its own and because of the example which it set. The role of the colonial government naturalist was pioneered there. Concepts of species extinction also emerged clearly, for the first time, on Mauritius and the island also saw the emergence of a legislative conservation policy rooted in a desiccation theory which linked deforestation and soil erosion to hydrological and climatic conditions. Notions of environmental moral economy and the significance of the tropical island are also explored in the chapter, in the context of the emergence of pre-Revolutionary radicalism, Physiocracy and early Romantic thinking. Chapter Four attempts to deal in some depth with the intellectual background to the early nineteenth century response of the British to ecological change in India. The importance of German science and a German 'romanticist' critique of ecological change is outlined and some emphasis is given to the emergence of a 'global' approach to the interactions between people (especially Europeans) and the environment. In particular the significance of the intellectual links between the Cook Voyages and the careers of J.R. Forster, Sir Joseph Banks and Alexander Von Humboldt is stressed. A beginning is also made in the task of surveying the way in which German professional naturalists and doctors deliberately sought out British colonial employ, a phenomenon that was to be important in the emergence of state conservation in India, the Cape, Australia and in other colonies. The chapter makes clear the continuing importance of small island environments during the nineteenth century in stimulating an awareness of environmental vulnerability, particularly for Alexander Beatson, William Burchell and J.B. Boussingault.

The ecological interrelationships between the habitat composition, habitat quality and abundance of three wild ungulate species, viz. Chital (Axis axis), Sambar (Cervus unicolor) and Nilgai (Boselaphus tragocamelus) were investigated in three National Parks in India. The study sites differ in the structure and composition of the habitat and also occur along a rainfall gradient. The study incorporates a new approach of using forest compartments for gathering baseline ecological data. The significance of these compartments in serving as ecological bench-marks for monitoring habitat condition has been demonstrated. Toe-point transect, a modification of the point-intercept method has been extensively used to obtain rapid, reliable but coarse ecological data on ground and aerial cover and the results obtained are compared with those from the visual estimation method. Motorcycle and foot-based line transects have been used to obtain data on animal abundance. The significance of the results indicating that motorcycle transects are an efficient and reliable means of estimating the abundance of Chital and Nilgai, while foot transects provide more reliable estimates of Sambar abundance is discussed. Data on 22 habitat variables were gathered in the summer and winter seasons from all the study sites and were statistically analysed using Generalized Linear Interactive Modelling (GLIM) procedures. The habitat requirements of the three ungulate species have been determined, which enhance our understanding of the complex herbivore-habitat relationships. Analyses of habitat selection, central to the understanding of animal ecology, has been done to understand the mechanisms which permit species to co-exist. The results indicate that the three species are ecologically separated and that resource partitioning is achieved primarily by habitat partitioning. Sambar, a forest ungulate, largely occurs in the forest-woodland habitats; Chital, a species of the habitat 'edge', occurs in the woodland-grassland habitats while Nilgai prefers the miscellaneousopen and grassland habitats. The three ungulate species together contribute more than 78% to the total wild ungulate biomass. This is presumably because these species are by nature generalist and are able to exploit the unpredictable resources more efficiently than specialist species. The differential biomass/rainfall relationships of three species observed in the study have been explained on the basis of habitat requirements and feeding strategies adopted by these species. The ecological biogeography of the three ungulate species has been discussed and their ecological equivalents in Africa have been examined. The significance of above in enhancing our understanding of evolutionary biology is discussed. The study has shown that habitat composition is an all-important factor in large herbivore biology and that animal density may be used as an indicator of habitat quality.

The purpose of this study was to record the relationships between the reptiles and amphibians of Wise County and the ecological subdivisions of the area. Wise County was chosen because of the heterogenity of the area and because of its proximity to other counties which have been previously and similarly studied.

The changing spatial and temporal patterns in land use/land cover surrounding Zandvlei estuary were investigated over the period 1944 to 2005. Changes in the extent of four terrestrial and two aquatic land use/land cover categories were mapped from high quality aerial photographs using ArcView GIS. Basic spatial analyses were performed to quantify changes in area, 'edge-effects' and relative dominance through time. Semi-natural and seasonally inundated classes accounted for over 70% of land cover in 1944, but declined steadily as urban land use and permanently inundated land cover expanded to a present-day extent of 42% and 19% respectively. The following major drivers of change were identified: 1) the construction of the railway embankment bisecting Westlake wetland and Zandvlei estuary, which led to sedimentation and a change in plant species composition of the wetland, but decreased nutrient inflows into the vlei; 2) agricultural practices within the catchment at the start of the 20th century which increased sediment and nutrient inflows; 3) elevated water levels due to dredging operations between 1947 and 1961, which resulted in a significant loss of seasonally inundated land cover with concomitant changes in species composition and nutrient dynamics; and 4) urban development surrounding the vlei (with particular reference to Marina da Gama), which has expanded at the expense of semi-natural areas and significantly increased effluent and litter inputs into the vlei. A socially and ecologically balanced management policy governing the entire catchment is required to mitigate future impacts.

Up until the early 1990s conservation practices in South Africa were culturally biased, focusing largely on the value systems of the affluent. However, with the release in 1997 of the White Paper on the Conservation and Sustainable Use of South Africa's Biological diversity, the role that biological resources play in providing for the needs of all South Africans, is now emphasized. According to this policy, human needs must be considered if conservation is to be successfully implemented. Using this document as the framework for this study I chose to investigate various aspects of medicinal plant use in a rural community in Paulshoek, Namaqualand. The main aims were as follows: to evaluate the local knowledge regarding medicinal plants; to document the plants used and collected in Paulshoek; and to determine potential threats to the biological resource. This was achieved by employing a variety of social and ecological methods. It became apparent from the interactions and interviews with the residents that medicinal plants are an important resource to the Paulshoek community since more than 70% of the population regularly use herbal remedies. While there is some evidence to suggest that the local knowledge of medicinal plants is dying out, I would speculate that most of the knowledge has already been lost. Of the 15 plants used and collected in Paulshoek, most appear to be highly sustainable in the landscape. This conclusion was based on people's perceptions regarding the change in abundance of each of these species over time and by further comparing plant size between Paulshoek and adjacent commercial farms. As most medicinal species seem unaffected by either: harvesting or land use practices this indicates that it is possible to achieve a sustainable harvest. Certain species do, however, show evidence of decline. Fuelwood harvesting most probably accounts for the change in abundance of Rhus burchelli over time, while Mentha longifolia may be facing some reduction in plant fitness due to harvesting for medicinal purposes. Sceletium emarcidum is on the verge of local extinction due to a combination of intensive harvesting and high grazing pressures. In contrast, high stocking densities appear to account for the increased abundance in both Galenia africana and Ballota africana. These findings clearly show that while the resource as a whole may be fairly resilient to harvesting and land use practices, certain species are in need of urgent conservation. This study further highlights the need to look beyond the direct impacts of harvesting and consider all possible threats, if the resource is to be sustainably managed. While this case study is atypical of the state of the medicinal plant resource in most of South Africa, this survey serves as a novel protocol for evaluating the sustainability of any resource which is regularly utilized.

Game farming is becoming more popular in southern Africa and the introduction of large indigenous ungulates into confined enclosed areas could alter plant communities and ecosystem processes. This is of particular concern in semi-arid rangelands of the Succulent Karoo where the evolutionary history of grazing is not clear and the compatibility of large herbivores in confined areas remains to be demonstrated. The establishment of Sanbona Wildlife Reserve, a 54 000 hectare private game reserve in the Little Karoo, which converted from livestock farming to game farming, allows an opportunity to study the vegetation dynamics in a confined plant-herbivore system. This study investigates the current community structure and the changes in the floral composition and vegetation structure of enclosed and comparable sites subjected to grazing by large herbivores after twelve years (2004-2015). It also determines the relative effect of grazing and rainfall on the observed patterns. Finally, the implications of these findings for management are discussed. Data from drop-point surveys in fenced (exclosure) and unfenced (grazed) plots in the dominant vegetation types as well as annual and seasonal rainfall totals, stocking rates of herbivores and annual game census information, were analysed. These were used in multivariate ordination techniques, regressions and linear mixed-effects models to determine the communities and their relationship with herbivory and rainfall over time and identify a set of indicator species. The annual game census information was used to determine areas of herbivore preference or 'hotspots' and for the identification of highly-utilised areas. Cluster analysis, using the flexible beta method in PC-Ord, was used to determine the current plant communities. Non-metric multidimensional scaling ordination (NMS) was used to determine the relationship of these communities with the environmental variables and illustrate the trajectories in floristic data. Species were also assigned to plant growth forms and examined as communities and growth form types. The Bray-Curtis distance measures were used to investigate the difference between each treatment over time, within each vegetation community and between treatments. Finally, the effects of rainfall and herbivory were examined using linear mixed-effects models of change over time vs the various potential determinants of change using lmer functions in R. Four communities were identified. These communities corresponded well with to the vegetation type descriptions for Western Little Karoo, Little Karoo Quartz Vygieveld and Renosterveld as described in the National Vegetation Map of Mucina and Rutherford (2006). However, the Western Little Karoo was too broad and two communities were recognised within this vegetation type. The finer scale mapping by Vlok et al. (2005) corresponded relatively well to these communities. Results showed an increase in species richness, abundance and cover over time, with the ungrazed plots experiencing more change than the plots exposed to grazing. Most growth forms exhibited an increase in cover, although low leaf succulents declined in both grazed and ungrazed plots. Medium evergreen shrubs declined in the exclosures and stem succulents declined in the grazed plots. The effects were found in both grazed and ungrazed treatments. In addition, many species which declined in abundance were unpalatable or toxic to herbivores. Because of this, the decline in cover of such species was not attributed to grazing, but was instead interpreted as being a response to other disturbance mechanisms, to competitive displacement and to rainfall events. The low stocking rates in the first five years of the study resulted in there being very little difference evident between the treatments. However, once stocking rates increased from 2008, both species richness and cover increased more rapidly in the ungrazed plots, compared to the grazed plots. An increase in palatable and unpalatable species was observed within both ungrazed and grazed plots indicating that grazing did not change the proportion of palatability classes. However, specific plots in the areas of high animal utilisation were more affected as indicated by the response of cover, species richness and palatable species in these specific plots. This suggests that the grazing pressure may be too high within those areas. The linear mixed-effect model supports the argument that grazing pressure is the dominant driver of the community change within grazed plots. Similarly, the results show that rainfall is the primary driver of the vegetation community in the absence of grazing. Timing, amount and intensity of rainfall can mask these impacts. Thus, the contribution of grazing to vegetation change can probably only be detected by tracking the trends over decades or longer. The use of indicators as a management tool is well documented. In order to identify indicators, a theoretical framework for determining indicators species in the different vegetation communities was created. This was based on the correlation between species abundance and sampling period in the different treatments, which identified species that have significantly increased or decreased over time as a result of the change in land use. Species identified as potential indicators were selected on the basis based on their abundance and ranged in lifespans and palatability. The indicators chosen need to be monitored into the future to confirm their utility as indicators. A small but significant difference between grazed and ungrazed plots suggest that herbivore impact is apparent. Identifying this trend indicates that the monitoring programme is providing a useful tool for assessing the impact of herbivores on an ongoing basis. The recovery process following the withdrawal of domestic livestock from Sanbona was much slower in the grazed plots than in the protected plots. Therefore, for the continued recovery of the vegetation to occur and for there to be a sustained increase in cover, active management of animal numbers needs to take place. The results from this study can contribute to future management decisions on the reserve and form a basis for future analyses.