Browsing by Subject "Environmental Conservation"

Now showing 1 - 4 of 4
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    Open Access
    Conservation priorities and management recommendations for the Erongo Region Coastal Zone, Namibia
    (1996) Du Preez, D; Braby, Rob; Williams, Tony; Fuggle, Richard Francis; Butcher, Shirley
    The most intensively used part of the Namib Coastline, the area between Walvis Bay and the Ugab river, contains some of the most important and most sensitive natural habitats. Apart from their ecological value, these habitats also attract large numbers of tourists. Tourism is one of the main sources of income in the coastal area of the Erongo Region, therefore it is in the interest of Namibians that these habitats are utilised in a sustainable way. The Department of Resource Conservation of the Ministry of Environment and Tourism is responsible for managing the West Coast Tourist Recreation Area as well as the wildlife in all of Namibia. Conservation managers from this Department have identified sites in the study area that are important for maintaining healthy populations of rare, threatened or endemic species or species of international and regional importance. These sites must be managed in such a way that their conservation and tourism value is not detrimentally reduced. In order to assist conservation managers with the allocation of resources, the sites that were identified are divided into three priority groups, namely imperative, urgent and desirable. The evaluation for priority rating was done according to the criteria of conservation value, tourism value and threats. Sites were compared using pair-wise comparison, and groupings were obtained through cluster analysis. The sites that were identified, their main reason for conservation, most important threats and management recommendations are listed below according to the priority groupings. Management recommendations are only done for the two highest groupings, namely the imperative and important sites.
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    Open Access
    The ecology and management of the Kaapsehoop cycad (Encephalartos laevifolius Stapf and Burtt Davy)
    (1990) Zunckel, Kevan; Meadows, Michael E
    The Kaapsehoop Cycad (Encephalartos laevifolius Stapf and Burtt Davy) has the international, national, and provincial status of "endangered" by virtue of a number of factors which threaten it with extinction. It occurs in only three disjunct populations in southern Africa, of which two are very small and have only adult plants. This situation suggested the need for specific action to ensure the conservation of the plant within its natural habitat. This study was initiated in an attempt to respond to this call for action. The aims of the study were set at gaining an understanding of the ecology of the cycad, establishing the exact nature and extent of the factors threatening it with extinction, and presenting management guidelines as to how the plant and its habitat may be managed to ensure their conservation. Chapter One includes a background to the botanical significance of cycads in general, the reasons for the endangered status of E. laevifolius and a list of aims and objectives. The latter are briefly; to develop. an understanding of the ecology of this cycad, determine the nature and extent of the threats which have placed it in the ''endangered" category, and establish means of managing the plants and their habitat so as to mitigate these threats . The methodology followed to achieve the latter is presented in Chapter Two. The results achieved from work carried out by the author are presented In Chapter Three, and they are then discussed in Chapter Four, together with those obtained from other researchers and experts in the field of cycad ecology and management. From this it becomes apparent that the major factor threatening the plants continued existence in nature, is its illegal removal by unscrupulous collectors. The use of fire as a management tool may cause the loss of sexually propagated off-spring if not based on ecological principals. This would be tragic as the percentage of fertile seed being produced at present is extremely low. Besides the latter two abiotic threats, there are two biotic threats which are also .cause for concern. They are the rotting of the female cones and seed by a pathogenic infection, and the destruction of newly growing tissue by the caterpillars of the Leopard Moth. The insights gained from the study are drawn together as conclusions in Chapter Five. Where these indicate specific management measures or directions for further research, recommendations are made. It must be emphasized that although this study has been used for the enhancement of the author's academic qualification, it is vitally important that the recommendations made be seriously reviewed by those responsible for the conservation of this cycad. If this study is simply put on the shelf after it has achieved its academic goal, the possibility of E. laevifolius becoming extinct is very real.
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    Potential implications of climate change for Rooibos (A. linearis) production and distribution in the greater Cederberg region, South Africa
    (2015) Lotter, Johanna Magdalena; Van Garderen, Emma Archer; Tadross, Mark; Valentine, Alex
    Wild plants assist in supporting human livelihoods worldwide, both within traditional systems of medicine, and as economically useful plants. Indigenous to the Fynbos biome in the north-western part of the Western Cape, South Africa is the leguminous shrub, A. linearis (rooibos), which is extensively used as ethnomedicine by local communities, while also commercially grown and exported for the herbal tea market. Being a range-restricted species, climate change poses a threat to wild plants and their dependent communities, as well as the sustainability of the rooibos industry. Climate mediated impacts on rooibos are mostly substantiated by anecdotal evidence from commercial growers and local communities and have traditionally been insufficiently addressed. This study integrates predictive modelling and empirical data to provide important insights into rooibos' plant physiological functioning in the presence of climatic and environmental constraints. The aim is to determine whether there is evidence of climate change over the rooibos distribution area, how these climate anomalies are expected to affect the species distribution and to perform experimental studies by testing plant physiological functioning of A. linearis under changing climate conditions. Analysis of climate parameters important for rooibos production (rainfall frequency and intensity, temperature extremes and wind speed) have shown that plants will experience a shorter period of water availability during winter, and prolonged exposure to summer conditions (high temperatures and water stress) in the coming decades. Under these conditions, climate envelope modelling suggests that wild and cultivated rooibos types are at risk to lose between 49.8% and 88.7% in the extent of the bio-climatically suitable localities, most notably along the western and northern periphery of the rooibos production area by 2070. Plant physiological responses (growth analysis, gas exchange parameters and leaf carbon and nitrogen isotope ratios) to the assessed climate anomalies were measured in experimental studies at glasshouse and field scale. Specific adaptation mechanisms (increasing water use efficiency, developing a higher level of sclerophylly and altering the allocation of plant reserves) which helped seedlings to survive short term drought in the glasshouse were not able to offset more severe conditions in field settings. Finally, a comparison of wild and cultivated tea has shown an apparent adaptive advantage of wild tea to tolerate increased aridity with greater water economy, and more reliance on biological nitrogen fixation for N nutrition, indicating a potentially less severe scenario of range contraction for wild types than initially indicated. This study provides a more robust prediction of rooibos plant responses to climate change factors to enable more effective adaptive planning and conservation management in a changing climate.
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    Sand plain fynbos conservation : the Kenilworth Racecourse case study
    (1991) Brown, Lynette B; Meadows, Michael E
    The current extent of Sand Plain Fynbos and threats to its survival are examined, with a view to proposing effective means of managing areas of high conservation priority. Extensive depletion of Sand Plain Fynbos has resulted from agricultural development, urbanisation and its susceptibility to invasion by introduced woody plant species. The need to conserve this veld type is apparent in that only 0.05% of the original Cape Flats Sand Plain Fynbos still survives within scattered refugia. A mere 3.8% of this already minute fraction is represented in proclaimed nature reserves, clearly illustrating the neglected conservation status of this veld type. The majority of the remaining habitat owes its survival, albeit in various stages of degradation, to low impact land uses not related to conservation per se. The in-fields of the three racecourses on the Cape Flats in total comprise the land use supporting the largest area of Sand Plain Fynbos. This suggests the potential compatibility of such a land use with conservation in the longer term. Of the three racecourses, Kenilworth is the most important in terms of area, diversity and unprecedented numbers of threatened flora and fauna of the fynbos it supports. This provides a case study on which to base an assessment of the trends in species survival on small remnants. A historical backdrop to the isolation and degradation of the Kenilworth Racecourse and neighbouring remnants is provided. The predictions of conservation theory for the long-term viability of such small and isolated remnants are then reviewed. To determine the effects of recent events and processes on the conservation merits of Kenilworth Racecourse, species extinctions and turnover from 1950 to the present are determined for the flora and avifauna respectively. Past and current species checklists form the basis of this analysis. Causes of species loss are investigated by comparing the physical attributes and habitat preferences of the species present with those which have apparently become extinct locally. The influence of private landownership on the conservation security of Kenilworth Racecourse is of fundamental importance to its future conservation. In this respect, the likelihood of change in land use of the in-field fynbos, as well as the Racecourse area as a whole, is a crucial factor addressed in this study. The present and future operating requirements of the Racecourse Management are also determined and their likely effects on the natural system are assessed. The study establishes a need for conservation management at Kenilworth Racecourse. The approach adopted to achieve the ongoing conservation of the area is through the development of a Conservation Management Plan. The latter has been derived through reasoned and personal interaction with the Racecourse Management and is aimed towards integrating the needs of the Management with the ecological requirements for the natural system under its control. The creation of corridors to facilitate migration of biota, as well as the reintroduction of those species which have become extinct locally, are described as an adjunct to these proposals. The implementation of an organised burn programme is proposed as a management procedure to counteract species loss. Evaluation of initial success resulting from the Management Plan reveals that there is now an improved communication channel with the Management. This encompasses moral obligations for eradication of alien vegetation, abstention from further drainage of wetlands, prevention of future encroachment of parking within the natural system and an agreement to cease indiscriminate dumping of refuse material. A major constraint facing the conservation of the area is the reluctance of the Management to allow public interest groups direct involvement with monitoring and implementation of proposals presented within the Management Plan. The research findings and conservation management approach generated by the study are important because they have potential for promoting the long term conservation of analogous remnants, not only within the fynbos biome, but in other similar systems further afield. Although threats exist to the ongoing survival of Sand Plain Fynbos remnants, these should not prejudice their selection as areas worthy of sound conservation management. Remnants have inherent value as refugia. They are also of potential importance as sites for reintroduction of species that have become extinct locally, as educational resources and as relatively low-maintenance open spaces within the urban landscape.