Browsing by Author "Grindley, J R"
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- ItemOpen AccessAn assessment of recreational carrying capacity at Infanta, South Cape(1984) Sowman, Merle Rozanne; Grindley, J RA proposal to develop 100 additional residential erven at Infanta, a holiday township on the South Cape coast, prompted this study. Current pressure of human activities imposed on the Infanta coastal and estuarine environment during peak holiday periods is determined from questionnaire analysis and direct observations. Projections of potential recreational demand anticipated at the proposed higher level of development are made. An assessment of recreational carrying capacity indicates in broad terms what levels of use are acceptable for the different recreational activities pursued in the area. At the present population pressure these levels are already attained or exceeded for most activities. Major physical, ecological and social constraints for further township development are identified. The beach and swimming area, as well as ancillary shore facilities for boats, are already inadequate to support current recreational pressure. Increased recreational pressure will result in competition for water space and conflicts between different recreational interest groups will occur. Surveys conducted during this study suggest that particular bait and shellfish organisms (e.g. Alikreukel) are already overexploited. There is also evidence of a decline in the numbers and size of fish caught. At one recreation site, bank erosion and destruction of salt marsh vegetation is indicative of heavy boating and watersports activities. An increased holiday population would result in overcrowding at recreation sites. This would reduce the quality of the recreation experience for both the present holidaymakers and newcomers to the area. It is concluded that both the environmental resources and existing man-made amenities in the area are already stressed by present recreational pressure and cannot support an increased holiday population during peak holiday periods. Increased development will destroy the attributes which attracted development in the first instance. Additional township development which will increase population numbers during peak holiday periods should not be permitted. It is recommended that an evaluation of present recreational pressure, projections of potential recreational demand and an assessment of recreational carrying capacity based on physical, ecological and social constraints should be a routine procedure in the consideration of applications for the extension or establishment of coastal townships.
- ItemOpen AccessCango Cave, Oudtshoorn District of the Cape Province, South Africa : an assessment of its development and management 1780-1992 : short title, Management problems at Cango Cave(1992) Craven, Stephen Adrian; Grindley, J R; Davies, R J; Marker, Margaret ENo detailed investigation has been previously made of the legal status, administration, history, management, finances, and conservation status of a show cave in South Africa. This study, using archival sources and field work, makes a thorough assessment of Cango Cave, a well-known show cave in the Swartberg foothills north of Oudtshoorn in the Cape Province of South Africa. Repeated field trips to Cange Cave and to other caves in the area have confirmed the environmental deterioration of Cango Cave and its surroundings. This study has shown that such deterioration has been caused by human pressures on a non-renewable resource. Reading of the extensive Government and other archives, supplemented by newspaper and other published material, has for the first time enabled the scientific, administrative and financial history of the Cave to be available in one document. Analysis of this assembled evidence, augmented by reading between the lines where the evidence is occasionally missing, has shown the reasons for the failure of successive Cave managements during the past two centuries to operate on a conservation basis. This failure to conserve Cango Cave has occurred despite the avowed policy of every political master of the Cape since 1820 that the Cave is a national asset which shall be conserved. The thesis commences with a description of the location and topography of Cango Cave, followed by a review of cave conservation literature and a summary of the published information on the Cave. There follows a detailed account of the discovery and development of the Cave from 1780 until 1992, and an assessment of its financial status. The impact of humans on the Cave, and its conservation status, are examined in detail. The above data are then discussed at length, and the reasons for the present unsatisfactory management structure identified. Having demonstrated the past and present management failures at Cango Cave, recommendations are made for better management structures and for the necessary applied research. Such research will provide the information which is essential for the future management of Cango Cave on a conservation basis.
- ItemOpen AccessThe effects of recent landuse on a fynbos site(1982) Brownlie, Susan F; Grindley, J R; Boucher, CLanduse from 1920 to 1981 on the Fynbos Biome Research site at Pella, approximately 40 kilometres north of Cape Town, South Africa, and its immediate environs was studied to investigate possible causal relationships between Landuse and management practices and the resultant ecosystem. Fire has constituted the major perturbation in recent history. Prior to 1960 the Fynbos Site was intentionally fired on a 3 to 4 year rotation, possibly effecting net nutrient losses to the system. After 1960, unintentional burning occurred on average every 7 years. The Fynbos Site has been lightly browsed by livestock from 1920 to 1976 and bushcut between 1965 and 1970, with minimal long-term effects. Gravel quarry pits were dug in 1971 and subsequently abandoned, constituting disturbed soils prone to colonisation by invasive acacias. The increase in cultivated land surrounding the site after 1962 served to isolate the fynbos stand from nearby fynbos communities and exacerbate erosion of soils and their subsequent deposition on the Fynbos Site. Extraneous transformation of land has served to facilitate the progressive encroachment of pest plants, principally Acacia Saligna and A. cyclops, on the Fynbos Site. The uncontrolled spread of these plants poses severe threat to the persistence of this fynbos stand. The need to incorporate possible extraneous influences on potential conservation areas into management considerations is discussed, as is the importance of size and shape of a conservation-worthy area and the need to plan viable networks of reserves in the coastal lowlands of the Western Cape.
- ItemOpen AccessThe effects of recreational activities on aquatic avifauna(1984) Rowlands, Beaumont W; Hey, D; Grindley, J RThe Rietvlei wetland system, 10 km north of Cape Town, South Africa, supports 158 species of birds (Winterbottom,1960), and is the principal wetland for breeding waterbird numbers in the south-western Cape Province. It is an important collection, pairing and distribution centre prior to the breeding season. Emerging mudflats during evaporation in late summer are a major gathering point for waders before migratory departure. Increasing human pressure on open spaces is threatening this natural habitat of aquatic birds. For future waterbird conservation it is necessary to ascertain the impact of recreation and human disturbance in this area. Recreational activities on the northern of two dredged lakes in the northwestern corner of Rietvlei are therefore examined to investigate possible causal relationships between recreational activity and the numbers and behaviour of aquatic avifauna. Counts of waterbirds were carried out in the presence of people involved with various forms of recreational activity. These observations were made between February and May 1983. As a null hypothesis it is proposed that recreational activities on this lake and wetland system do not have a significant effect upon water birds in the area. The method used to test this hypothesis is based on statistical analysis by computer, with disturbance measured by means of correlation coefficients between recreational activities and bird numbers. The major findings (Chapter 5) and subsequent recommendations (Chapter 6) for waterbird conservation on the Rietvlei dredged lakes are presented, and proposals for further research in this field are suggested.
- ItemOpen AccessAn enquiry into gamefarming in the Cape Province(1983) Colvin, Ian Stuart; Fuggle, Richard Francis; Grindley, J RGamefarming in Africa has generally failed to exploit the potential biological productivity of indigenous wildlife populations. This study enquired as to the reasons for such failure within the Cape Province. The enquiry focused on management, research and marketing aspects of gamefarming. Personal interviews, a questionnaire and a literature analysis provided the information for the study. A description of the overall gamefarming situation is provided. Those management problems identified here found to be largely dependent on individual farmer's methods and the intensity of game utilisation. The primary uses of game were aesthetic appreciation and sport hunting. Such usages, being of low intensity, were accompanied by low levels of management effort. The lack of a stable economic incentive was found to be the major inhibition against adopting intensive commercial means of game utilisation by cropping, safari hunting and live sale.
- ItemOpen AccessAn environmental study of the Lourens River estuary(1983) Cliff, Sally; Grindley, J RAn environmental study of the Lourens River estuary was completed, whereby field surveys were undertaken and all available knowledge was collated. The Lourens estuary is a small system opening into False Bay, Southwestern Cape; it is almost entirely enclosed within AECI security fences and access to the public is restricted. Physicochemical parameters exhibit seasonal variations and the estuary may be marine dominated in summer and river dominated during the wet season. Terrestrial and aquatic biota are generally depauperate. The poor ecological quality of the estuary may be attributed primarily to periodic pollution inputs from the AECI main drain discharge, but also to the complex arrangements of land ownership and administrative controls and the influences of urban, industrial and agricultural developments in the river basin. It is recommended. that attention be paid to the management and conservation of the Lourens River system.
- ItemOpen AccessFactors affecting the conservation of renosterveld by private landowners(1988) McDowell, Clive Robert; Grindley, J R; Moll, EJWest Coast Renosterveld, once prevalent on the south-western Cape lowlands of the floristically rich Cape Floral Kingdom, is now South Africa's scarcest vegetation type. Delimitation and measurement of the 55 "island-remnants", scattered amongst agricultural lands indicated that only 3% of the original vegetation remains. Measured soil quality, gradient and rainfall (critical agricultural criteria) were used to derive agricultural 'threat' indices (probability of agricultural clearance) for each remnant. The indices agreed well with observed trends in the recent clearance of remnants not deliberately conserved by landowners. This new approach has potential for determining which remaining natural sites most urgently need preservation. It was demonstrated that agro-technical innovation poses a long-term threat to even the low agricultural 'threat' rated renosterveld. Pasturage, invariably practised in renosterveld, was assessed by comparing "grazed" with "ungrazed" plant species covers. Within the test site, heavy grazing increased Asteraceae and Iridaceae, decreased Poaceae and Rutaceae, and eradicated Proteaceae. These changes may reflect local trends associated with modern grazing regimes. Total plant diversity and cover were not found to be affected. Therefore, controlled pasturage reflects a relatively minor threat to the extinction of floristic elements. Private landowners are found to control the destiny of 80% of West Coast Renosterveld. The conservation attitudes and behaviour of a random sample of these critical decision-makers were analysed. A new approach was devised to assess 32 subjective, bias-prone "intangible" variables. This required additional assessors to provide independent, non-parametric ratings of the author's tape-recorded interviews with the landowners. Results were pooled and "inter-assessor" measurement error was estimated. Altogether 52 variables, including a further 20 "tangible" variables, were rated under categories: 'Demographic', 'Psycho-Social, 'Land Use' and 'Conservation Strategy'. A correlation matrix portrays inter-relationships between variables and their correlations with landowner "Conservation Behaviour". Landowners' knowledge of biota, rapport with interviewer, education, affluence, bilingualism, and parents' education all correlated positively with conservation. Linear equation models were derived (using Best Subsets Statistical Programme) to predict 'Conservation Behaviour'. Although most conservation related variables are "fixed" (e.g. it is not possible to change parents' education), the understanding of these background factors (not previously applied to conservation of natural ecosystems) enables choice of the most appropriate strategy to persuade landowners to conserve. Different groupings of landowners having similar ratings of key variables have similar needs and constraints to be considered vis a vis improving their "Conservation Behaviour".
- ItemOpen AccessHuman impact on the Cape of Good Hope Nature Reserve(1982) Benkenstein, Howard; Fuggle, Richard Francis; Grindley, J RThe problem investigated in this study is the environmental effect of outdoor recreation on a valuable conservation area, the Cape of Good Hope nature reserve. The approach adopted views the reserve as a business concern that produces service commodities from the resources of the natural environment. Supply of these commodities was estimated from a visitor activity profile obtained by combining traffic count data with timed observations on visitor behaviour. Demand was assessed from the results of a visitor survey and from information obtained from a literature review. The results of these investigations provided a data base for formulating a business management policy for the reserve. The findings of the study were that the shortage of open space in Cape Town and the Western Cape is a human ecological problem and that a business management policy which reinforces human behavioural links with the environment would be both an economic solution and an eco- logical solution to the current controversy surrounding matters related to conservation in the Cape of Good Hope nature reserve.
- ItemOpen AccessThe importance of water levels in the management of the Klein River Estuary, Hermanus(1987) Waldron, Miranda Elizabeth; Morant, Patrick D; Grindley, J RThe Klein River Estuary is situated at Hermanus in the Western Cape, South Africa. The estuary mouth is normally closed by a sand berm during the summer and open to the sea during the wetter winter months. The estuary forms a shallow lagoon which is becoming increasingly popular for recreational activities. Several management problems have arisen which are now becoming important with the increase in recreational pressure. The main problems are: uncertainty about appropriateness of water levels, marine sand influx and accumulation, flooding of low lying developments, flooding of agricultural lands, decrease in fish catches and indecision about the ideal position of the estuary mouth in the sand berm. This study concentrates mainly on the effects of different possible water levels. The conclusion is that the estuary water level should be permitted to rise at least as high as the highest level investigated. The estuary should be allowed to breach the sand berm. Developments on low lying land, prone to flooding, should be prohibited and only those structures which would not be damaged by flooding should be allowed in such areas.
- ItemOpen AccessPollution control investment decisions and policy preferences of senior managers of the Southern African fish processing industry(1990) Lipschitz, Steven; Fuggle, Richard Francis; Grindley, J RPollution control regulations directed at the land-based factories of the Southern African fish processing industry do not appear to promote the required level of investment in pollution control systems. Two self-administered mail-questionnaires comprising undisguised fixed-alternative and open-ended questions were constructed to survey the opinions and viewpoints of a census consisting of twenty-seven senior managers responsible for making pollution control investments in the demersal and pelagic sectors of the fish processing industry. The first questionnaire was directed at establishing the relative importance of factors that influence waste and pollution control investment decisions as well as the perceptions and preferences of managers with regard to various pollution control policy options. Descriptive statistics such as the modal class were used to summarize the distribution of opinions and viewpoints within the research population. Rank ordered preference data was analyzed using a multidimensional unfolding computer algorithm. This structural multivariate statistical method is a special case of non-metric multidimensional scaling that generates perceptual maps which can aid in the discovery of the hidden structure underlying multidimensional decisions. Investments in waste and pollution control do not appear to have a high priority when compared to other strategic investments that the fish processing industry managers may make. The relative importance of factors that could influence the managers of the industry to invest in waste control equipment appear to be determined by the perceived financial returns that can be expected from such investments. Findings suggest that pollution control legislation is rendered ineffective due to inadequate enforcement. However, it appears that existing legislation needs to be rationalized in order to facilitate compliance. The most favoured pollution control instruments were those that lowered the cost of legally mandated expenses such as subsidies and income tax allowances. These were followed by permit systems which specified the allowable characteristics of discharges while allowing individual companies freedom of choice as to the method of achieving compliance. The second questionnaire was used to verify the researcher's interpretation of the findings and preliminary conclusions drawn from the replies to the first questionnaire.
- ItemOpen AccessA rationale for maintaining natural and near-natural areas in developing countries(1980) Stauth, Roy Bryan; Fuggle, Richard Francis; Grindley, J RThis dissertation seeks to establish that certain natural goods are systematically undervalued and neglected in the decision-making processes of private and public institutions. It is further argued that these natural goods lend security to and enhance the quality of life, hence their continued existence and functioning have considerable value for the survival and well-being of this and future generations. Decision-makers are therefore advised of the need to establish the level at which these natural goods will be maintained in order to prevent their continued decline past some critical point.
- ItemOpen AccessThe use of digitally interpreted satellite imagery, with special reference to topographical shadow effects, as an aid to vegetation mapping in the Hottentots Holland Mountain catchment area of the Western Cape Province(1984) Newby, Terence Styan; Grindley, J RThis report includes a summary account of the operation of the LANDSAT 2 satellite and describes some of the procedures for extracting information, relating to vegetation, from digital imagery. The effect of topographic shadow on the imagery is explained and a short discussion of mountain fynbos, the natural vegetation of the mountains of the Western Cape Province of South Africa, is included. The report explains the methods used to estimate the amount of shadow on the imagery of the study area and to investigate the potential of various spectral band ratios for giving useful management information. It was found that approximately seventeen percent of the image of the Hottentots Holland Mountain Catchment Area is affected by topographic shadow. No meaningful information could be extracted from the shadowed areas, by digital image processing. Band ratioing did however, result in strong correlations between spectral values and vegetation height, percentage cover and biomass, as well as leaf surface area, veld condition and aspect, for sun illuminated areas.