Browsing by Author "Midgley, G. F."

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    Diversity and species turnover on an altitudinal gradient in Western Cape, South Africa : baseline data for monitoring range shifts in response to climate change
    (AOSIS, 2008) Agenbag, L.; Esler, K. J.; Midgley, G. F.; Boucher, C.
    A temperature and moisture gradient on the equator-facing slope of Jonaskop on the Riviersonderend Mountain, Western Cape has been selected as an important gradient for monitoring the effects of climate change on fynbos and the Fynbos-Succulent Karoo ecotone. This study provides a description of plant diversity patterns, growth form composition and species turnover across the gradient and the results of four years of climate monitoring at selected points along the altitudinal gradient. The aim of this study is to provide data for a focused monitoring strategy for the early detection of climate change-related shifts in species' ranges, as well as gaining a better understanding of the role of climate variability in shaping species growth responses, their distributions, and other ecosystem processes.
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    Monitoring effects of anthropogenic climate change on ecosystems : a role for systematic ecological observation?
    (Academy of Science for South Africa, 2007) Midgley, G. F.; Chown, S. L.; Kgope, B. S.
    WE CONSIDER HERE THE OPPORTUNITIES and challenges for South Africa in long-term ecological research (LTER) to detect the impacts of anthropogenic climate change on biota (as one of several competing objectives of long-term monitoring). The LTER approach has high potential for this purpose in South Africa because of a wealth of historical climate data relative to much of the African continent, and good representation of many African ecosystem types. However, there are substantial challenges to the identification and attribution of climate change impacts on African ecosystems. These are posed by climate variability at a range of time scales, the importance of rainfall rather than temperature as an ecological driver, and the significance of fire as a stochastic disturbance. An awareness of environmental and climate history will be crucial to interpreting data on trends, and sites with established historical data should be preferred for this reason. The placement of LTER sites to provide representivity of ecosystem types may unintentionally limit the detectability of climate change impacts, because change might best be detected in ecotonal or azonal environments. This could be overcome by additional experimental manipulations at LTER sites to 'force' anticipated changes and characterize species and ecosystem responses. A focus on the detection of climate change would sharpen an LTER programme's emphasis over time and provide policy advice, and science training rationales for the long term. It should especially interpret key information to decision-makers as a priority.