Browsing by Author "Midgley, Guy F"

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    Ecological aspects of the substrate and water relations of deciduous and evergreen plant forms in the western Karoo
    (1989) Midgley, Guy F; Moll, Eugene J; Rutherford, MC
    The principle aim of this work was to ascertain the relative importance of water and nutrient supply in determining the success of deciduous and evergreen plant forms on two main substrate types in the Worcester-Robertson valley, situated in the Succulent Karoo Biome. The substrate types selected for study represent soils of zoogenic soil mounds (locally termed "heuweltjies", and often referred to in the literature as "Mirna-like" mounds), and soils immediately adjacent to and surrounding the soil mounds. The distribution of deciduous and evergreen plant forms in the Worcester-Robertson valley was analys~d relative to the selected substrate types. Foliar elemental concentrations of four selected species growing on both substrates at five separate sites within the valley were determined. Also, the patterns of seasonal water stress exhibited by three deciduous and five evergreen non-succulent woody perennials growing in both substrates were investigated on high radiation (equator-facing) and low radiation (pole-facing) slopes at one intensive study site, the Worcester Veld Reserve.
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    Exploring the significance of land-cover change in South Africa
    (2012) Gillson, Lindsey; Midgley, Guy F; Wakeling, Julia L
    Changing land cover is a phenomenon that is growing in magnitude and significance, both globally1 and in South Africa2 . Changes in land cover include the conversion of natural vegetation to agricultural crops and forest plantations, changes to natural vegetation through bush encroachment and overgrazing, soil erosion, invasion by alien plant species, and accelerating urbanisation. Land-cover changes increasingly relate to climate and atmospheric changes in ways that are currently poorly understood but potentially significant, especially in terms of compromising or enhancing the delivery of vital ecosystem services from rangelands, agricultural croplands, water catchments and conservation areas. Land-cover change is being studied in different ways, and at different scales, by ecologists, plant physiologists, applied biologists and social scientists. A core group of scientists has recently formed the Land Cover Change Consortium (LCCC), which aims to begin integrating the results of the varied approaches to studying land-cover change, and to guide future research directions, with a view to building a better science base for informing policy and management decision-making in conservation, agriculture and environmental management. The group has developed a simple conceptual outline that links field experiments, observation and monitoring, modelling and prediction of land-cover change (Figure 1), and is currently developing a funding base to support collaboration in addressing fundamental questions about how ecosystems might change in the coming decades, in training new graduates, and in communicating effectively with policymakers. The LCCC hopes to provide a theoretical and practical multidisciplinary platform for scientific collaboration on global change issues that also includes different stakeholder groups and contributes to policy and decision-making. Multidisciplinary collaboration is notoriously challenging, but holds great promise for novel insights.