Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv & Cons Biol)

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https://hdl.handle.net/10566/13183

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Browsing by Author "Boatwright, James"

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    Impacts and control of alien Proteaceae invasion in the Western Cape Province, South Africa
    (University of the Western Cape, 2017) Erckie, Laimi Nelago Koskima; Boatwright, James
    Research focused on ecological impacts and control of invasive alien species (IAS) is gaining attention worldwide. The eradication and control of invasive alien plants (IAP) is essential for the restoration of native plant communities. Understanding ecological impacts and potential invasive risks of IAP is important for their effective management, particularly for prioritisation. Most studies concerning impacts on vegetation structure and plant-pollinator interactions have measured few ecological metrics, resulting in a superficial understanding of plant species invasion. Additionally, most studies related to the control of IAP have focused on major invaders which have demonstrated severe impacts, with less focus on emerging invaders. This study assessed ecological impacts, invasive risks and chemical control options for alien Hakea drupacea and Banksia species in the Western Cape Province, South Africa. Multiple ecological metrics data on vegetation, soil and plant-pollinator parameters were measured and compared between invaded and uninvaded sites. The invasion risk of fourteen Banksia species which have been introduced to South Africa was evaluated by conducting a weed risk assessment (WRA). The herbicide efficacy of resprouting Banksia integrifolia and Banksia serrata was determined by rating plants response to different treatments, with percentage, height and resprout vigour as measures. Results revealed significant negative impacts of alien H. drupacea and Banksia speciosa invasion on native plant species richness and diversity and on the abundance of native pollinators. The study demonstrated that 79% of Banksia species have a high risk of invading the Fynbos Biome. Chemical control with triclopyr+picloram mix provided effective means of controlling resprouting Banksia species. The high invasive risk of Banksia species and competitive effects of invasive alien B. speciosa and H. drupacea with native plant species for biotic and abiotic resources represents a major threat to biodiversity conservation in the Fynbos Biome. The removal of both naturalised and invasive alien H. drupacea and Banksia populations is recommended in order to conserve native plant communities in the Fynbos Biome.
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    Systematics of subtribe Anthosperminae and the generic affinities of Anthospermum and Nenax (Rubiaceae: Anthospermeae)
    (University of Western Cape, 2021) Nemando, Rangani; Boatwright, James
    The last taxonomic treatment of the subtribe Anthosperminae was in 1986 by Puff., nevertheless, few attempts have been made to resolve the phylogeny and the inter- and infrageneric relationships within the subtribe. The genera Anthospermum L. (39 species) and Nenax Gaertn. (11 species) are considered the most difficult groups to distinguish. Anthospermum species are widely distributed in Sub-Saharaan Africa and Madagascar with the highest concentration of taxa in southern Africa, while Nenax species are restricted in southern Africa, south-western Cape Floristic Region. The two genera share common morphological and anatomical characters.
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    Taxonomy and invasive potential of the Cassiinae in southern Africa (Caesalpinioideae, Fabaceae)
    (University of the Western Cape, 2019) Liada, Musandiwa; Boatwright, James
    Cassiinae is a large subtribe of the tribe Cassieae (Caesalpinioideae) that comprises ca. 700 species distributed throughout the Americas, Africa, Eurasia and Australia. The southern African species of Cassiinae (indigenous, naturalised and cultivated) were all treated under Cassia L. in Gordon-Gray’s (1977) treatment for the Flora of southern Africa. However, given the subsequent generic recircumscriptions in the subtribe and the expansion of collections of these taxa since, this treatment is now outdated. The aim of the present study was to provide an overview of the subtribe Cassiinae in southern Africa, assess the invasive potential of all naturalized species (viz. Cassia s.s., and Senna Mill.) and conduct a detailed taxonomic revision of the species of Chamaecrista (L.) Moench. indigenous to southern Africa.