UWCScholar :: Browsing by Author "Knight, Richard"

Browsing by Author "Knight, Richard"

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Adequacy of existing protected areas in conserving biodiversity at global and regional levels in relation to socio-economic conditions
(University of the Western Cape, 2005) Gaika, Lindiwe; Knight, Richard; Faculty of Science
At a meeting of worl leaders at the United Nations Conference on Environment and Development in Rio de Janeiro in 1992, it was recognized that because of the tremendous increase in the size of the global populations (which now is estimated to exceed six billion), there were concerns that global biodiversity was at risk if insufficient land were not put aside for conservation within formal Protected Areas. The primary aim of this study was to compare investment in Protected Areas in relation to socio-economic conditions at global and regional levels.
An analysis of the fire regime and its effects on post-fire recovery in Namaqualand Granite Renosterveld vegetation
(University of the Western Cape, 2017) Simons, Megan Brigette; Knight, Richard
Namaqualand Granite Renosterveld (NGR) is a fire-prone shrubland largely confined to the Kamiesberg Uplands. More than 20% has been transformed by agricultural activities such as grazing and dryland cropping. The history of fires of Namaqualand Granite Renosterveld was assessed over a period from 2000 - 2015. Furthermore, this study aimed to assess the effects of fire and grazing on the dynamics of Elytropappus rhinocerotis and the post-fire vegetation recovery. Satellite imagery, field observations and combination of field sampling techniques were used to compile a comprehensive fire database and to collect data on vegetation parameters. The Kamiesberg Uplands has a human-induced fire regime with a fire frequency of 4.2 years, which appears to be shorter for NGR compared to other Renosterveld - types. The majority of the fires were in summer and early autumn which is the ecologically accepted season with high fire intensities. Fire Danger Index ratings for summer burns were in the dangerous and very dangerous categories. In terms of cover, the distances between E. rhinocerotis individuals were significantly more on the burnt than on the unburnt sites. The density of unpalatable species on the burnt sites is also strongly associated with E. rhinocerotis. Elytropappus rhinocerotis appears to facilitate a role as a nurse-plant for various species in renosterveld. The local biotic and abiotic conditions, allows E. rhinocerotis to maintain its abundance, thus displaying niche construction by a single species.
Assessing livestock farmers' ecological knowledge and adaptation to climate and environmental change in arid regions of South Africa
(University of the Western Cape, 2017) Ntombela, Khululiwe Primrose; Knight, Richard
Challenges that come with micro-level climate change projections have resulted in the inadequacy of our understanding of local climatic changes and the appropriate adaptation strategies. This has resulted in indigenous communities relying on their local knowledge for local scale climatic changes and suitable adaptation practices. Coping and adapting to climate and its impacts has been occurring since human existence, however, humans are still vulnerable due to the rapid rate that the climate is changing. Adaptation is vital for all global people, especially living in semi-arid or arid regions, as it provides a solution for food shortages and livelihoods. Global livestock farmers have, over many years, accumulated local ecological knowledge; and it is from this knowledge that decisions are made. Local knowledge related to adaptation to climate change and variability has largely not been recognized or documented and it is only lately that it is deemed to be critical in formulating policies to mitigate the harsh effects of the rapidly changing climate. This study was focused on the local knowledge and understanding of climate change and variability (and associated environmental change) with its impacts and adaptation of communal livestock farmers in the semi-arid regions of the Northern Cape Province in South Africa. Two communal areas namely, Leliefontein and Steinkopf in Northern Cape served as study sites. A case study approach, with triangulation of focus group discussions and semistructured interviews, was used. The focus group discussions were aimed at drawing up a seasonal calendar, where 10 livestock farmers from Leliefontein and 14 from Steinkopf participated. The focus group discussions were followed by indepth semi-structured interviews, where a total of 20 livestock farmers from each study site were interviewed. While various other studies highlight the lack of awareness and understanding of climate change among livestock communal farmers, this study found that 90 % and 55 % of the interviewed Steinkopf and Leliefontein livestock farmers had an understanding of the phenomenon. The interviewed farmers referred to the phenomenon of climate change as "seasonal shifts" that they have been experiencing. Findings of the study indicated that intergeneration knowledge transfer and media sources contributed as sources of climate and farming management information. The basic, but wealthy knowledge of farmers informs them of potential climate change impacts and possible adaptation strategies. The study also revealed that even though adaptation measures are being carried out by livestock farmers I n the two study sites, that there are general barriers which include financial, biophysical environment, social and institutional barriers that inhibit effective adaptation. Recommendations from this study were that policies should consider and protect local knowledge; and that the factors that affect successful adaptation strategies of communal livestock farmers should be considered when adaptation programmes are planned.
Carbon sequestration in cultivated and uncultivated Vachellia karroo sites in Tankwa Karoo National Park
(University of Western Cape, 2021) Phophe, Paulina Avhavhudzani; Knight, Richard
The Succulent Karoo Biome (SKB) in South Africa is widely reputed to house Earth’s greatest diversity of succulent plants. It is also famous for spectacular displays of annual flowers after good rains. The area experiences winter rainfall which infrequently exceeds 100 mm per annum but certain parts of the SKB can get 250 mm. Irrigated agriculture on a large scale was therefore not a viable option when European farmers began colonizing the land. The land was conquered from the indigenous Khoekhoe herders and San hunter-gatherers, South Africa’s first peoples. The biome underwent extreme transformation in the last 200 years following colonisation which resulted in homogenization of the landscape and extinction of many succulents thus reducing biodiversity.
Conservation and resource-use relations: Analysis for protected area expansion feasibility in the Western Cape
(University of the Western Cape, 2022) Dyssel, Michael; Knight, Richard
It is assumed that expanding the size and/or number of protected and conservation areas can contribute to more effective conservation, ecosystem services and environmental protection. Expansion is normally a response to continuous environmental threats and subsequent needs to enhance the protection and conservation of valuable biodiversity, geodiversity and heritage assets. Targets for global, regional and country-based protected area expansion are set and driven by conservation authorities across different geographical scales – from the global International Union for the Conservation of Nature (IUCN) to the local-level protected area.
Corporate Social Responsibility in the South African forestry industry – a Western Cape perspective
(University of the Western Cape, 2013) Sass, Theodore; Goldin, J.A.; Knight, Richard
Globally plantation forestry plays a pivotal role in terms of timber production, ecological services and maintaining local livelihoods. In South Africa commercial forestry occupies a relatively small portion of the total land area, but contributes significantly towards the national GDP. Forestry had been labelled as a streamflow reduction activity. Thus further afforestation is not possible. It is of paramount importance that plantations are managed on a sustainable basis in order to meet future timber demands. However, sustainability goes beyond the replenishment of natural resources or economic prosperity and also includes social responsibility. (CSR) initiatives are a means for companies to maximize the positive contribution their operations can make to the promotion of fair work practices and ecological sustainability. Plantations are mostly located in rural areas and often reflect the only form of local employment. Often employees are at risk of economic exploitation and high risk of injury while little scope for economic and educational betterment exists. CSR incorporates people, planet and profit. It is important to fulfil the basic needs of the workers in order for the company to realize environmental and economic prosperity. It is the aim of this study to highlight the essential role of people in insuring the long-term sustainability of the Western Cape plantations. The primary aim of this study is to investigate the over-all well-being of forestry workers in the Western Cape plantations. In order for people to reach the over-all goal of the organization, they first need to satisfy their basic needs. More often than not this is the case with forestry workers. Some of the issues that negatively impact on their over-all wellbeing are:  Their working environment and conditions  Lack of investment in resident / neighbouring communities  Lack of adequate stakeholder consultation  Poor standards of worker accommodation If companies wish to be sustainable, they need to address these issues that forest workers are being confronted with. The secondary aim of this study is to explore CSR initiatives that could address these issues in the Western Cape plantation villages.This study deploys a mixed approach, using both qualitative and quantitative methods. Data were collected through the distribution of structured questionnaires, interviews, meetings, company documents and reviewed literature. The research shows that the social issues that confront forest villages include poor sanitation facilities, lack of home ownership, poor state of worker accommodation, lack of extramural activities, substance abuse and relatively low remuneration rates. The company also faces challenges with regards to the implementation of its CSR programme. This study makes several recommendations which are based on the findings. One such recommendation is a tripartite approach to CSR. Here a tripartite approach refers to the partnership between the company, Government and civil society.
Developing fixed-point photography methodologies for assessing post-fire mountain fynbos vegetation succession as a tool for biodiversity management
(University of Western Cape, 2020) Alkalei, Osama; Knight, Richard; Harebottle, Doug
Areas of high biodiversity and complex species assemblages are often difficult to manage and to set up meaningful monitoring and evaluations programmes. Mountain Fynbos is such an ecosystem and in the Cape of Good Hope (part of the Table Mountain National Park) plant biodiversity over the last five decades has been in decline. The reasons are difficult to speculate since large herbivores, altered fire regimes and even climate change could be contributors to this decline which has been quantified using fixed quadrats and standard cover-abundance estimates based on a Braun-Blanquet methodology. To provide more detailed data that has more resolution in terms of identifying ecological processes, Fixed-Point Repeat Photography has been presented as a management “solution”. However, photography remains a difficult method to standardize subjects and has certain operational limitations.
Identifying and mapping invasive alien plant individuals and stands from aerial photography and satellite images in the central Hawequa conservation area
(University of the Western Cape, 2012) Forsyth, Aurelia Therese; Knight, Richard; de Klerk, Helen M.
The Cape Floristic Region, situated at the southern tip of Africa, is one of the world’s most botanically diverse regions. The biodiversity of this region faces various types of threats, which can be divided into three main categories, namely increasing urbanisation, agriculture expansion, and the spread of invasive alien vegetation. It has been shown that botanically diverse areas are more prone to invasion by invasive alien plant (IAP) species. The Hawequa conservation area, in the south-western Cape, is particularly botanically diverse, such that it is very prone to aggressive invasion by IAP species. Therefore, conservation management of the Hawequa conservation area urgently need to map, prioritise and clear IAP species. Due to the topographical complexity of this mountainous area, it is not possible to map the distribution of IAP species throughout the protected area by conventional field methods. Remote sensing may be able to provide a suitable alternative for mapping. The aim of this research was to assess various image classification methods,using two types of high-resolution imagery (colour aerial photography and WorldView-2 satellite imagery), in order to map the distribution of IAP species, including small stands and individuals. Specifically, the study will focus on mapping Pinus and Acacia spp. in a study site of approximately 9 225ha in the Hawequa conservation rea. Supervised classification was performed using two different protocols, namely per-pixel and per-field. For the per-pixel classification Iterative Self-Organising Data Analyses Technique (ISODATA) was used, a method supported by ERDAS Imagine. The per-field (object-based) classification was done using fractal net evolution approach (FNEA), a method supported by eCognition. The per-pixel classification mapped the extent of Pinus and Acacia spp. in the study area as 1 205.8 ha (13%) and 80.1 ha (0.9%) respectively, and the perfield classification as 1 120.9 ha (12.1%) and 96.8 ha (1.1%) respectively. Accuracy assessments performed on the resulting thematic maps generated from these two classification methods had a kappa coefficient of 0.700 for the per-pixel classification and 0.408 for the per-field classification. Even though the overall extent of IAP species for each of these methods is similar, the reliability of the actual thematic maps is vastly different. These findings suggest that mapping IAP species (especially Pinus spp.) stands and individuals in highly diverse natural veld, the traditional per-pixel classification still proves to be the best method when using high-resolution images. In the case of Acacia spp., which often occurs along rivers, it is more difficult to distinguish them from the natural riverine vegetation. Using WorldView-2 satellite images for large areas can be very expensive (approximately R120 per km2 in 2011), but in comparison with the cost of mapping and the subsequent clearing, especially in inaccessible areas, it might be a worthwhile investment. Alternative image sources such as the high resolution digital colour infrared aerial photography must be considered as a good source for mapping IAP species in high altitude areas.
Impacts of degradation on critically endangered Oudtshoorn Gannaveld
(2010) Wheeler, Alan David; Knight, Richard
In the Succulent Karoo biome of South Africa vegetation degradation by overgrazing is a recognized threat to biodiversity. In the eastern Little Karoo region of the Western Cape Province, ostrich farming has degraded large areas of natural vegetation, particularly in the Gannaveld habitat of the Oudtshoorn basin. Little quantified vegetation data exists on the impacts of degradation and the composition of the Gannaveld vegetation types. This study quantifies the composition of Oudtshoorn Gannaveld and the impacts of degradation on this critically endangered vegetation type. The diversity of this vegetation type is added to by the occurrence of mima-like circular soil mounds, termitaria, which support distinctive plant assemblages. Perennial plant data and soil data were collected from the largest remaining remnant of Oudtshoorn Gannaveld perceived to contain different levels of degradation from near pristine to severely degraded. The results show 72 species in 49 genera and 17 families were recorded with the Aizoaceae, Asteraceae and Amaranthaceae families being dominant. The off termitaria plant community is dominated by the Asteraceae, Aizoaceae and Crassulaceae families while the on termitaria community is dominated by the Asteraceae, Amaranthaceae and Zygophyllaceae families. Four levels of degradation were identified in each of the broader on and off termitaria communities. It was found that grazing and trampling induced degradation on termitaria results in the loss of perennial plant cover and plant litter and an increase in bare ground while degradation off termitaria results in a loss of species. There are changes in soil chemistry both on and off termitaria as a result of vegetation degradation. Degradation results in palatable species being replaced by unpalatable and disturbance indicating species. Perennial plant cover off termitaria is resilient to grazing and trampling, however species richness, plant functional type composition and the abundance of individual species are not. Species richness on termitaria is resilient to grazing and trampling but cover, plant functional type composition and the abundance of individual species are not. Degradation results in shifts from succulent and woody shrub dominated communities to dwarf succulent and dwarf succulent shrub dominated communities. These changes hold implications for agriculture,biodiversity conservation and the provision of ecosystem services.
Impacts of the invasive reed Arundo donax on biodiversity at the community-ecosystem level
(University of the Western Cape, 2007) Guthrie, Gené; Knight, Richard; van Wilgen, Brian; Faculty of Science
Arundo donax is an invasive species that mostly impacts on sensitive riparian ecosystems. Arundo is also invasive in South Africa, though less is known about its ecology, biology, and impacts. Since California and the Western Cape of South AFrica have similar Mediterranean-type climates, we could assume that the impacts of Arundo on ecosystems in California are likely to be similar in the Western Cape, and that control methods used could be extrapolated for use in South Africa. This thesis attempted to determine what impact Arundo has on biodiversity at the community-ecosystem level.
Post-Fire response of botanical and microbial communities in the succulent Karoo
(University of the Western Cape, 2018) Lucas, Lyle; Knight, Richard
Fire as a form of disturbance is unique in the way it impacts upon the environment, acting like a herbivore with a ubiquitous appetite. Consuming both dead and living material, converting complex organic molecules into organic and mineral products, which return to the soil. The role of disturbance has long been considered a driver of diversity within Mediterranean type ecosystems. Recently the interest in soil microbes has been piqued, as the importance thereof has been emphasised, particularly their role in nutrient cycling and the chelation of essential plant nutrients. The occurrence of fire results in several environmental and ecological impacts on soil, as well as the dynamics of the microbial populations present. This study explores the impact of fire as a disturbance on the plant and bulk soil microbial communities of the Succulent Karoo. This was achieved through two sub-studies, in which three different states were studied: unburnt, 7-year and 2-year post-fire. Today microbial profiles are also used as indicators of disturbance, thus many techniques exploring microbial community composition are available.
Rehabilitation as a method of understanding vegetation change in Paulshoek, Namaqualand
(University of the Western Cape, 2005) Simons, Liora-lee; Allsopp, Nicky; Knight, Richard; Faculty of Science
Heavy grazing of rangelands in the succulent karoo has placed the biodiversity of these areas at risk. In Paulshoek, overgrazing has resulted in the removal of much of the palatable vegetation from low lying areas. The remaining vegetation is dominated by Galenia africana, an unpalatable shrub. Loss of favourable microsites, competition from Galenia africana, as well as loss of seed banks, may be the cause of poor seedling establishment of palatable species. I explored how high grazing pressure has changed this system by comparing with surrounding private farms, which have a history of less concentrated grazing pressure. I found that heavy grazing increased the seed bank of Galenia africana in the soil and reduced that of palatable perennials. Vegetation cover was significantly lower (p<0.0001) under heavy grazing and consisted mainly of Galenia africana and few palatable perennials. The aim of this study was to test techniques that could restore this area to a more productive palatable shrubland. I propose that rehabilitation can be used to gain an understanding of the ecological factors that may be sustaining this altered vegetation state. My methodology involved biophysical interventions to manipulate this system. Grazing pressure was removed from the study area and vegetation changes were monitored under grazed and protected regimes. No change in plant cover was found after two years. However, there was an increase in cover of palatable perennials in relation to overall cover. I physically manipulated the environment by introducing microcatchments and brushpacks to act as traps for water, seed and organic material. These interventions resulted in few changes, however, I found higher soil moisture levels in microcatchments and under brushpacks than open positions. Cover of ephemerals was also significantly higher (p<0.001) in areas that had been brushpacked. In the absence of a seedbank, I tested whether the introduction of seed would result in recruitment. Seed of four palatable perennial species was sown into open, packed and tilled soil. A low number of seeds germinated in the first year and most seedlings died. Further germination occurred after a rainfall event in the second year, but still in very low numbers. Various microhabitats were implemented to assess seedling establishment requirements. Seedlings were transplanted in microcatchments and open positions; in areas cleared of Galenia, under adult Galenia and brush packs and in bare soil. Microhabitats did not facilitate seedling establishment, and few seedlings survived. Survival of seedlings was influenced by the size of seedling at transplantation and site differences. I conclude that the factors underlying vegetation change are complex. Individual physical and biological interventions offered no immediate change in vegetation cover and composition. However, a combination of interventions may over time and under favourable climatic conditions allow the return of a viable palatable shrubland.
A Remote sensing change detection study in the arid Richtersveld region of South Africa
(University of the Western Cape, 2007) Main, Russell Stuart; Knight, Richard; Faculty of Science
The Richtersveld falls within the succulent karoo and dester biomes. This studu made use of remote sensing technologies in order to investigate possible vegetation cover changes that have taken place over time, and which have manifested through a combination of threats to the region. Te aims of the study were adressed using three key questions that sought to gainan understanding of the relationship between vegetation response and moisture, in order to interpret teporal and spatial vegetyation cover changes. A spartially and temporarily representative remotely sensed dataset was used together with techniques that are repeatable and able to quantify change with a limited human bias.
Renosterveld conservation in South Africa: A case study for handling uncertainty in knowledge-based neural networks for environmental management
(International Society for Environmental Information Sciences, 2009) Chandra, R.; Knight, Richard; Omlin, C. W.
This work presents an artificial intelligence method for the development of decision support systems for environmental management and demonstrates its strengths using an example from the domain of biodiversity and conservation biology. The approach takes into account local expert knowledge together with collected field data about plant habitats in order to identify areas which show potential for conserving thriving areas of Renosterveld vegetation and areas that are best suited for agriculture. The available data is limited and cannot be adequately explained by expert knowledge alone. The paradigm combines expert knowledge about the local conditions with the collected ground truth in a knowledge-based neural network. The integration of symbolic knowledge with artificial neural networks is becoming an increasingly popular paradigm for solving real-world applications. The paradigm provides means for using prior knowledge to determine the network architecture, to program a subset of weights to induce a learning bias which guides network training, and to extract knowledge from trained networks; it thus provides a methodology for dealing with uncertainty in the prior knowledge. The role of neural networks then becomes that of knowledge refinement. The open question on how to determine the strength of the inductive bias of programmed weights is addressed by presenting a heuristic which takes the network architecture and training algorithm, the prior knowledge, and the training data into consideration.
Spatial analysis of open space in the quaternary catchment of the Lourens river
(2011) Raitt, Gwendolyn Rose; Knight, Richard
This thesis looks at aspects relating to vegetated open space in the quaternary catchment of the Lourens River, Cape Town, South Africa in 2005 and at GoogleEarth as a source of imagery for research. The research questions were: “Is GoogleEarth a suitable source of imagery for spatial analysis of landscapes?”; “What was the potential access (proximity) to vegetated open space of at least 900 m2 in the Lourens River quaternary catchment in 2005?”; “How many vegetated open spaces with an area of at least 900 m2 were present in the Lourens River quaternary catchment in 2005?” and “What spaces within the urban edge in the Lourens River quaternary catchment can be said to have some protection from development?” Open space has multiple benefits for humans in terms of health and social interaction.In urban areas, it is also important for biodiversity conservation. In Cape Town, this is critical since the city has critically endangered national vegetation types that only occur within its boundaries and 319 IUCN Red List species within its boundaries.Proximity does not reflect use of open space which is affected by the size of the open space, quality of the open space, neighbourhood attributes and individual and collective perceptions of the open space. Quality of vegetated open space is dependent on its facilities and maintenance which are largely determined by its management. In Cape Town, open space management is mainly mowing/brush cutting all spaces which has a negative impact on biodiversity retention. Mowing is continued because of popular demand so action needs to be taken to change popular perceptions.Google Earth is readily available and widely used. It is used for research in diverse disciplines. Local Internet connection problems complicated this study. Alignment and projection problems were encountered in this study. Thus Google Earth geospatial issues make it a poor choice of imagery source for large scale spatial analysis of landscapes.Open space was digitized in Google Earth and transferred to a propriety GIS for editing. Vegetated spaces with a minimum of 900 m2 and a width of at least 15 m were selected from the approximately 1025 digitised spaces. Google Earth imagery was used because it is readily available. Euclidean distances of 300 m, 500 m, 800 m and 900 m (taken from literature) were used to buffer the digitized vegetated open spaces and other data on schools, train stations, bus routes and taxi routes in and within 900 m of the catchment. Buffer analysis was carried out. Data from the City of Cape Town and a schools layer were used to determine the number of cemeteries,community parks, nature reserves and school grounds – space regarded as having some protection from development - within the urban edge of the city and what area they covered.Within or partially within the Lourens River quaternary catchment, 593 vegetated open spaces of at least 900 m2 were identified. The analysis showed that only two houses were beyond 300 m from a vegetated open space. There was vegetated open space within 300 m of all the schools, stations, bus and taxi routes within the catchment and in close proximity to the catchment. Within the urban edge, only 124 spaces were found to be protected, of which only one was a nature reserve.Most of the open spaces are not formally designated as open space and are vulnerable to development. Much development has taken place since 2005 in the Lourens River quaternary catchment so action is needed to ensure proximity to vegetated open space remains a positive feature of the area.Expanding the present research to cover a larger area would provide additional baseline data. Further research could consider the loss of open space over time and the impact of management on the quality of designated open space.
Spatio-temporal dynamics in land use and habit fragmentation in Sandveld, South Africa
(University of the Western Cape, 2010) Magidi, James Takawira; Krug, Cornelia B.; Knight, Richard; Faculty of Science
This research assessed landuse changes and trends in vegetation cover in the Sandveld, using remote sensing images. Landsat TM satellite images of 1990, 2004 and 2007 were classified using the maximum likelihood classifier into seven landuse classes, namely water, agriculture, fire patches, natural vegetation, wetlands, disturbed veld, and open sands. Change detection using remote sensing algorithms and landscape metrics was performed on these multi-temporal landuse maps using the Land Change Modeller and Patch Analyst respectively. Markov stochastic modelling techniques were used to predict future scenarios in landuse change based on the classified images and their transitional probabilities. MODIS NDVI multi-temporal datasets with a 16day temporal resolution were used to assess seasonal and annual trends in vegetation cover using time series analysis (PCA and time profiling).Results indicated that natural vegetation decreased from 46% to 31% of the total landscape between 1990 and 2007 and these biodiversity losses were attributed to an increasing agriculture footprint. Predicted future scenario based on transitional probabilities revealed a continual loss in natural habitat and increase in the agricultural footprint. Time series analysis results (principal components and temporal profiles) suggested that the landscape has a high degree of overall dynamic change with pronounced inter and intra-annual changes and there was an overall increase in greenness associated with increase in agricultural activity. The study concluded that without future conservation interventions natural habitats would continue to disappear, a condition that will impact heavily on biodiversity and significant waterdependent ecosystems such as wetlands. This has significant implications for the long-term provision of water from ground water reserves and for the overall sustainability of current agricultural practices.
A systematic conservation plan for threatened freshwater wetlanddependent waterbirds across South Africa
(University of Western Cape, 2020) Daniels, Neil; Knight, Richard; Desmet, Phillip
Freshwater ecosystems are valuable to all components of biodiversity communities. Globally, these ecosystems are threatened by human activity and as a consequence, many vertebrates, including waterbirds, have become threatened. Wetlands are one of the most productive ecosystem types in the world. Yet, despite this, many protected area networks around the world fail to include this ecosystem type in their protected area networks. On a national scale, in South Africa, wetland loss and deteriorating wetland habitat quality continues to restrict and reduce the range of wetland waterbirds. For this thesis, Maximum Entropy (MaxEnt) species distribution modelling was used to identify additional areas of possible waterbird occurrence. The MaxEnt results noted that waterbirds rely on a combination of these environmental variables for their distribution ecology in their wetland habitat, with vegetation and humidity variables having the highest predictive powers. These would be considered important predictor variables for the distribution ecology of these waterbirds.
Valuing the natural resources and ecosystem services of Leliefontein communal rangeland in Namaqualand, South Africa.
(University of the Western Cape, 2014) Ogidan, Oluwagbenga Olaitan; Knight, Richard; Cupido, Clement
Natural resources play important roles in ecosystem service delivery, more especially in rural households where livelihoods depend heavily on natural resources for the delivery of ecosystem services. The various benefits derived from provisioning, supporting, regulating and cultural services of natural ecosystems such as food, medicines, carbon sequestration, spiritual fulfilment all support human life and sustain its well-being. Research on valuation of natural resources suggest that the values derived mainly from non-marketed natural resources are insignificant and thus, not reflected in national accounts. Economic valuations have traditionally been concerned with the quantification of direct use values of ecosystem services that are marketed to produce tangible benefits. The scope of natural resource valuations have, however been broadened by scientists in recent years to consider passive or non-use values to reflect the total economic values of natural resources and ecosystem services to societies. In this study, I valued the streams of ecosystem services derived from natural resources in Leliefontein communal rangeland; an area of 192 000 hectares in the semi-arid region of Namaqualand in South Africa. Rangeland forage for livestock, medicinal plants, fuelwood, and water resources from the Communal Area were valuated for one production year between January and December 2012. Valuation was done to incorporate both marketed and non-marketed natural resources which were used within the production year. The total economic value for the area was estimated at R20 156 672 per annum. Value of rangeland forage was estimated at R61.92 ha-1 yr-1, fuelwood’s value was estimated at R25.04 ha-1 yr-1, value of medicinal plants was R2.26 ha-1 yr-1 and water resources valued at R9.45 ha-1 yr-1. The non-use value was estimated by eliciting the willingness to pay for the conservation of the natural resources using a contingent valuation method. Economic value of natural resources in Leliefontein increased to R105 per hectare from R99 when non-use value was added to reflect the total economic value of ecosystem services in the area. Household income level positively correlated with individual’s willingness to pay for ecosystem services. I recommend that decision making should take into account the socio-economic conditions of a community when determining the total economic value of ecosystem services. Non-use value of the ecosystems should be considered especially in rural areas where people depend on the natural environment for livelihoods and socio-cultural well-being. Sustainable and equitable utilisation of natural resources for the purpose of maintaining a sustainable flow of critical ecosystem services should form the basis for formulating policies on land use and sustainable development.
The water quality and ecological status of the Diep river catchment, Western Cape, South Africa
(University of Western Cape, 2004) Ndiitwani, Tovhowani Brenda; Knight, Richard; Jonker, Lewis
The study illustrates the current ecological integrity of the Diep River system, based on the recent river health assessment using the South African Scoring System version 5 (2000-2003) and the water quality data (1996-2002). Some of the major land-use impacts on the river system are highlighted.

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