Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.659793
Title: The environmental effects of mangrove clearance in Belize, Central America
Author: Murray, Malcolm R.
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 1996
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Abstract:
The thesis begins with an examination of the pattern of global mangrove clearance. In Belize unlike many other countries, mangrove clearance is being driven by the current market requirement for housing, rather than industrial or agricultural demands. There is little local demand for mangrove related products (notwithstanding that many of the fish and crustaceans that use the mangrove forest as a nursery ground or habitat are commercially exploited). Analysis of recent clearance permit applications shows that mangrove forest clearance is rapidly accelerating around Belize City. The physical process of forest clearance in Belize is then outlined emphasising its effect upon the forest environmental processes. These are conceptualised in a series of predictive hypotheses considering the expected changes in a range of soil, water and other environmental properties following forest clearance. These are grouped into four - changes stemming from alteration to the little input; changes due to a reduction in the vegetation cover; changes driven by surface water and drainage modification; and finally changes determined by the geology and physical alteration to the ground surface. The significance of such changes in these measured properties is given in a discussion of mangroves stress tolerance and avoidance strategies. Published mangrove tolerance ranges and responses to critical levels of flooding, salinity, temperature, insolation, tidal action, sedimentation, wind, soil acidity, anaerobic state and the presence or absence of soil nutrients are reviewed, summarised in a series of flow diagrams. A field site sampling strategy is devised and three sites of different ages and stages in the clearance process are selected, to provide an insight into both the spatial and temporal aspects of change. A range of soil, water and environmental properties such as ground level insolation and litter cover are measured at these sites using both areal and transect sampling schemes. The resulting data are analysed using 3D visualisation techniques, comparative statistical testing (Mann Whitney-U tests and one way ANOVA) ordination techniques and semi-variogram analysis. These show that significant differences do exist between sites located in the forest and those in the newly cleared areas, with this difference changing through time and manifested at different scales across space. For some properties a third conceptual unit can be sustained - referred to as the "transition zone" - this straddles both sides of the clearance cut-line. By showing that changes occur in the forest soil and water properties in areas next to cleared sites, this thesis concludes with a re-evaluation of Belize's existing mangrove forest clearance legislation. It asks whether the current 66' wide mangrove forest buffer is sufficient to provide a sustainable protective barrier along Belize's coasts and waterways.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.659793  DOI: Not available
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