8 research outputs found
Land cover and climate change threats to savanna and grassland habitats in KwaZulu-Natal
A thesis submitted to the Faculty of Science, University of the Witwatersrand,
Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy
The support of the Global Change and Sustainability Research Institute (GCSRI) towards this
research is hereby acknowledged. Opinions expressed and conclusions arrived at, are those of the
author and are not necessarily to be attributed to the GCSRI.
February 2017 in Johannesburg, South AfricaGlobal change, specifically land cover change and climate change, are recognised as the
leading drivers of biodiversity loss worldwide. Habitat loss has resulted in a loss of
biodiversity and led to significant declines in species populations. Climate change is altering
species distributions, ecosystem composition and phenology. Conservation planning is
required to offset these dynamic threats to species persistence into the future.
Plants form the basis of trophic structure and functioning and may not be able to track
changing environmental conditions as well as mobile species. They thus represent an
essential starting point for understanding climate change and habitat loss impacts. The
patterns and processes which generate and maintain floristic diversity must be explored
before global change impacts on these communities can be assessed and planned for at a
landscape scale.
This thesis investigates the environmental variables structuring indigenous plant community
composition, pattern and turnover in grassland and savanna systems in KwaZulu-Natal. The
threats posed by land cover change and climate change are explored and a coarse-grained
landscape connectivity map developed to impart maximum resilience in order to maintain
floristic diversity in the era of anthropogenically induced global change.
The environmental variables correlated to floristic pattern and turnover were temperature, soil
fertility and precipitation variables. The orientation of the temperature gradient conflicts with
the soil fertility gradient, hence species with particular soil requirements will be hampered in
their efforts to track the temperature gradient. The gradients were non-linear with turnover
highest on dystrophic soils in warm and drier summer regions.
The major drivers of land cover change were cropped agriculture, timber plantations
(agroforestry), rural and urban development, dams and mines. The drivers of change differed
according to land tenure type. The average rate of habitat loss in the province over an 18 year
period was 1.2% per annum, levels which are considered unsustainable. A target level of 50%
of natural habitat remaining is recommended.
Environmental domains were identified using the environmental correlates of plant
community composition. These were used to investigate climate change impacts using a
collection of downscaled climate models. Conditions suiting savanna species are set to
increase at the expense of conditions suiting grassland species raising significant challenges
for the conservation of grasslands. Indices of habitat intactness and climatic stability were
used to develop a vulnerability framework to guide conservation actions to mitigate global
change impacts on floristic diversity.
Building on the insights gained from the study, a connectivity map linking protected areas
was developed, that if implemented, will maximise the opportunity to maintain floristic
diversity into the future. The spatial location of the corridors was prioritised based on broad
scale climatic refugia, high turnover areas and important plant areas for endemic and
threatened species. The corridors were aligned along the major climatic gradients driving
floristic pattern. The corridors represent the most natural and cost-effective way for species to
adapt to climate change and persist in the landscape.
This thesis provides new insights into two global threats facing plant communities in
KwaZulu-Natal and provides a suite of products that inform dynamic conservation planning
and directs appropriate conservation action. The results may be used to inform policy and
legislation.MT201
Displays of authority in the clinical consultation: A linguistic ethnographic study of the electronic patient record
AbstractThe introduction of computers into general practice settings has profoundly changed the dynamics of the clinical consultation. Previous research exploring the impact of the computer (in what has been termed the ‘triadic’ consultation) has shown that computer use and communication between doctor and patient are intricately coordinated and inseparable. Swinglehurst et al. have recently been critical of the ongoing tendency within health communication research to focus on ‘the computer’ as a relatively simple ‘black box’, or as a material presence in the consultation. By re-focussing on the electronic patient record (EPR) and conceptualising this as a complex collection of silent but consequential voices, they have opened up new and more nuanced possibilities for analysis. This orientation makes visible a tension between the immediate contingencies of the interaction as it unfolds moment-by-moment and the more standardised, institutional demands which are embedded in the EPR (‘dilemma of attention’). In this paper I extend this work, presenting an in-depth examination of how participants in the consultation manage this tension. I used linguistic ethnographic methods to study 54 video recorded consultations from a dataset collected between 2007 and 2008 in two UK general practices, combining microanalysis of the consultation with ethnographic attention to the wider organisational and institutional context. My analysis draws on the theoretical work of Erving Goffman and Mikhail Bakhtin, incorporating attention to the ‘here and now’ of the interaction as well as an appreciation of the ‘distributed’ nature of the EPR, its role in hosting and circulating new voices, and in mediating participants' talk and social practices. It reveals – in apparently fleeting moments of negotiation and contestation – the extent to which the EPR shapes the dynamic construction, display and circulation of authority in the contemporary consultation