Browsing by Author "Kalwij, J. M."

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    Frontiers of vegetation science : an evolutionary angle
    (International Association for Vegetation Science, 2008) Mucina, L.; Kalwij, J. M.; Smith, V. R.; Chytry, M.; White, P. S.; Cilliers, S. S.; Pillar, V. D.; Zobel, M.; Sun, I-F.
    The main focus of the symposium is to seek links between vegetation science and evolutionary biology and the formation of platforms in cooperation between these major scientific fields. The title of our meeting – “Frontiers of Vegetation Science—An Evolutionary Angle”– alludes symbolically to the challenges that vegetation science as a discipline is currently facing. Technologically driven progress in evolutionary research is changing the face of many traditional biological sciences. Vegetation science, should (and to some extent already does) react to this new phase of evolutionary research by reaching out to ecological disciplines traditionally closer to evolutionary biology (population biology, palaeo-ecology) and implementing tools of evolutionary research in explaining structure and dynamics of vegetation. The field of interaction and cooperation is enormous and is ripe for exploration and discovery. The major aim of our meeting is to extend the interface and to deepen the cooperation between the evolutionary research and vegetation science.
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    A spatial assessment of Brassica napus gene flow potential to wild and weedy relatives in the fynbos biome
    (Academy of Science of South Africa (ASSAf), 2009-04) McGeoch, M. A.; Kalwij, J. M.; Rhodes, J. I.
    Gene flow between related plant species, and between transgenic and non-transgenic crop varieties, may be considered a form of biological invasion. Brassica napus (oilseed rape or canola) and its relatives are well known for intra- and inter-specific gene flow, hybridisation and weediness. Gene flow associated with B. napus poses a potential ecological risk in the Fynbos Biome of South Africa, because of the existence of both naturalised (alien, weedy) and native relatives in this region. This risk is particularly pertinent given the proposed use of B. napus for biofuel and the potential future introduction of herbicide-tolerant transgenic B. napus. Here we quantify the presence and co-occurrence of S. napus and its wild and weedy relatives in the Fynbos Biome, as a first step in the ecological risk assessment for this crop. Several alien and at least one native relative of B. napus were found to be prevalent in the region, and to be spatially congruent with B. napus fields. The first requirement for potential gene flow to occur has thus been met. In addition, a number of these species have elsewhere been found to be reproductively compatible with S. napus. Further assessment of the potential ecological risks associated with B. napus in South Africa is constrained by uncertainties in the phylogeny of the Brassicaceae, difficulties with morphology-based identification, and poor knowledge of the biology of several of the species involved, particularly under South African conditions.