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dc.contributor.author Ringrose, S.
dc.contributor.author Vanderpost, C.
dc.contributor.author Matheson, W.
dc.contributor.author Wolski, P.
dc.contributor.author Huntsman-Mapila, P.
dc.contributor.author Murray-Hudson, M.
dc.contributor.author Jellema, A.
dc.date.accessioned 2008-07-24T10:58:45Z
dc.date.available 2008-07-24T10:58:45Z
dc.date.issued 2007-01
dc.identifier.citation Ringrose, S. et al (2007) Indicators of desiccation-driven change in the distal Okavango Delta, Botswana, Journal of Arid Environments Vol 68, Issue 1, January, pp. 88-112 en
dc.identifier.issn 0140-1963
dc.identifier.uri http://hdl.handle.net/10311/161
dc.description.abstract This work seeks to determine whether riparian woody plant variables respond to drying and salinity regimes in the semi-arid distal Okavango Delta, northern Botswana. Structural and compositional variables were obtained from 47 field sites. Mapping using satellite imagery illustrated differences in the character of riparian zones in terms of species composition and provided data on flood frequency. Salinity data plots show increases downstream. Results imply that woody plant variables respond to desiccation-driven change due to water-table lowering (reduced recharge) and increased salinization through distinct changes in tree and shrub height, plant density and species richness. In the wetter, intermediate distributaries, key biotic indicators of ecosystem change comprise structural variables such as decreases in canopy cover per cent and tree height and increases of shrub height, which are indicative of mainly ground-water declines. Biotic indicators in the less frequently flooded receiver channels comprise plant density and species richness increases involving mainly brackish ground-water-tolerant and dryland species which are indicative of both ground-water declines and/or salinization. These indicators could provide useful parameters for use in long- and short-term monitoring aimed at assessing desiccation-driven change in different parts of the Okavango Delta and possibly other semi-arid wetlands. The indicators are important as a less-expensive alternative to drilling as a means of verifying ground-water declines and/or salinization. en
dc.description.sponsorship This work was funded partly through the European Union WERRD project (ICA-4-CT-2001-10040) partly by the Botswana Department of Water Affairs (with Water Resource Consultants) and the University of Botswana (Research Grant 084). en
dc.language.iso en en
dc.publisher Elsevier Ltd; www.elsevier.com/locate/jaridenv en
dc.subject Semi-arid riparian zones en
dc.subject Compositional and structural variables en
dc.subject Water-table lowering en
dc.subject Salinization en
dc.title Indicators of desiccation-driven change in the distal Okavango Delta, Botswana en
dc.type Article en


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