Many smallholder farmers in southern Africa rely on crop production as their main livelihood source. However, they often suffer from a lack of appropriate seed as well as high levels of food insecurity. Interventions such as community seed production, seed aid, and input subsidies are used to address these concerns. However, the relationship between seed security and food security has been understudied. This study thus aimed to explore the factors that have an impact on the relationship between seed security and food security. This was done to enhance understanding about the conceptual linkages between the dimensions of seed security, which include availability, access, and utilisation, and those of household-level food security, which include dietary diversity and food consumption. The case study was conducted across two sites in Chimanimani district of Zimbabwe. Methods included both quantitative and qualitative research methodologies. Quantitative data were subjected to statistical analyses while qualitative data were analysed for themes and trends. Results showed the dominant role of informal seed systems in ensuring improved access to affordable and timely seed to smallholder farmers. Informal seed sources were more reliable than formal sources in ensuring that seed was available on time and in closer proximity to households. Seeds sourced informally also showed comparable quality to that from formal sources. The relationship between seed security and food security was shown to be complex and contextual rather than direct or one-directional. Seed security does not necessarily equate to food security, nor does seed insecurity necessarily lead to food insecurity. Although timeliness and proximity of seed affect its availability, these did not directly relate to access to food. Similarly, household assets and income correlated with better food security status, but did not always ensure access to seed. This is because farmers' seed sources were predicated on non-financial factors such as social relations. The quality of farmers' seed was essential in ensuring that adequate food was produced. The thesis argues that the combined factors of seed availability, access and utilisation are essential in ensuring better crop productivity and improved food access. Findings underscore the manner in which household determinants such as assets, farming practices and geographical characteristics, as well as broader contextual factors, affect and influence the relationship between seed and food security. These results imply that interventions such as community seed production, seed aid, and input subsidies do not automatically result in improved seed security and therefore food security. Efforts to enhance seed and food security should be informed by specific household characteristics that take account of wider contextual factors such as climate, as well as socioeconomic and political processes that have a historical influence as well as a continuously evolving effect on farmers' seed and food security.

Large-scale climate processes such as El Niño-Southern Oscillation (ENSO), Antarctic Oscillation (AAO), and many others, play varying roles in regional climate variability across the world. While the role of singular processes have been explored in many studies, the combined influence of multiple large-scale processes has received far less attention. Key to this is the challenge of developing methodologies to support the analysis of multiple processes interacting in potentially non-linear ways (co-behaviour) in a particular region. This study details the development of such a methodology and demonstrates its utility in the analysis of the co-behaviour of largescale process interactions on regional precipitation and temperature variability over southern Africa. The study defines co-behaviour as the interaction of large-scale processes that may influence regional circulation leading to climate variability. A novel methodology which involves a combination of analysis techniques such as Self-Organizing Maps (SOM) and Principal Component Analysis (PCA) is developed to identify and quantify such co-behaviour which accommodates potentially non-linear interactions. This methodology is evaluated in the context of southern African regional climate using three key processes, namely ENSO, AAO and Inter-tropical Convergence Zone (ITCZ), and characterizations of regional circulation, and temperature and rainfall variability. Analysis of co-behaviour under observed conditions identifies results that concur with prior studies, in particular the dominant regional response to ENSO, but also establishes key examples of co-behaviour such as the role of the AAO in moderating and altering the regional response to ENSO which is important for understanding regional climate variability. Application of the approach to Global Climate Model (GCM) simulations of past climate reveals that while many GCMs are able to capture individual processes, in particular ENSO, they fail to adequately represent regional circulation variability and key observed co-behaviour. The study therefore clearly demonstrates the importance of co-behaviour in understanding regional climate variability as well as showing the usefulness of the new methodology in investigating co-behaviour. Finally, the new insights into evaluating model performance through the lens of core climate processes and their interaction provides a significant step forward in both model development and application for decision making.

Conventional management approaches, focused primarily on stock status and top-down driven regulatory measures, such as are employed in many commercial fisheries across the globe, have proven to be inadequate in managing small-scale fisheries and have contributed to marginalisation of this sector. In South Africa, small-scale fisheries have been increasingly recognised since the abolishment of Apartheid and the advent of democracy in 1994. Nevertheless, the management approaches implemented have been largely top-down, natural science-driven and single-species approach. South Africa's fishery sector is currently going through a historic moment where all small-scale fishers are awaiting implementation of a new Small-Scale Fisheries Policy that will see it endorsing the holistic, multi-species and people-centred approach and the recognition of local and indigenous knowledge of fisheries and addressing the complex socio-economic needs of the fishers. However, in order to implement this policy using a co-management and EAF approach, Government and fishing communities will need to set up the required information-gathering and monitoring tool that would be in line with the principles and objectives of the South African Small-Scale Fisheries Policy as careful assessment of social and economic outcomes of fisheries policies is required to support and sustain livelihoods of these fishers. A proper information management system (IMS) would further ensure that the new approaches to small-scale fisheries management are practical and effective in managing this sector. In investigating the small-scale fisheries information management system, the researcher conceptualised and designed an IMS and further conducted case studies by analysing and work-shopping results of analysed catch data recorded by an independent service provider to Doringbaai small-scale fishers, and analysed catch data of East Coast Rock Lobster in the Eastern Cape of South Africa. Based on the results of the conceptualised and designed IMS and that of the analysed catch data, it is clear that there is a need for the IMS to be converted into a web-based system and further accommodate more indicators that would assist in equipping fishers and fisheries authorities with relevant decision-making. It is also clear that there is a need for an urgent overhaul in how catch data is gathered and packaged as there were numerous errors in the data that could affect how small-scale fisheries should be managed. One of the interventions urgently needed is implementation of an electronic data capturing and instant synchronisation of data into the IMS which would present live data through a web interface customised per user type. Such tool would improve the current management measures and further contribute to improving governance of small-scale fisheries when the Small-Scale Fisheries Policy is implemented.

Most contemporary urban development in cities of the global South is responding to rapid urbanisation caused by prospects of employment opportunities and improved quality of life. Research in the field of sustainability in cities of the global South mainly focuses on economic and social development goals. However, there is an emerging sense that an appreciation of ordinary, everyday practices at the level of the community is important for developing a nuanced understanding of what sustainability might be in Southern cities. There is agreement on the need to pay attention to social and cultural practices in urban sustainability literature; yet relatively little research in the field engages closely with everyday practices at the level of neighbourhoods or communities. This is particularly true in the global South, and especially in low-income urban neighbourhoods, where developmentalist agendas dominate both academic and policy-related research. My thesis addresses this gap through an exploration of a wide range of everyday practices in a lowincome, peri-urban area, which happen to have sustainable effects. Analysing ethnographic data collected over nine months in the Cape Town township of Nyanga, I find that the desire of urban residents to create spaces of home and belonging drives behaviour that in fact has positive sustainable outcomes, yet is seldom considered in literature on sustainable cities. I argue that paying attention to how ordinary citizens ‘make home', specifically by (i) drawing on memories, (ii) developing livelihoods, and (iii) building social relations can enrich understanding not only of economic and social development but also of the complex ways in which social and environmental sustainability are already intertwined in everyday practice. Facilitating sustainable spaces in cities of the global South, therefore, requires critical engagement with the practices that are already taking place in urban residents' everyday lives.

Includes abstract. / Includes bibliographical references. / The advent of terrestrial laser-scanners made the digital preservation of cultural heritage sites an affordable technique to produce accurate and detailed 3D-computermodel representations for any kind of 3D-objects, such as buildings, infrastructure, and even entire landscapes. However, one of the key issues with this technique is the large amount of recorded points; a problem which was even more intensified by the recent advances in laser-scanning technology, which increased the data acquisition rate from 25 thousand to 1 million points per second. The following research presents a workflow for the processing of large-volume laser-scanning data, with a special focus on the needs of the Zamani initiative. The research project, based at the University of Cape Town, spatially documents African Cultural Heritage sites and Landscapes and produces meshed 3D models, of various, historically important objects, such as fortresses, mosques, churches, castles, palaces, rock art shelters, statues, stelae and even landscapes.

This thesis provides an analysis of the discourses of nature conservation in South Africa and Driftsands provincial nature reserve from constructionist and environmental justice perspectives. At the outset I examine the theoretical framework on the social construction of nature and that of environmental justice. I then discuss the history of nature conservation in South Africa. Finally I analyse the discourse (nature conservation and local communities) surrounding the Driftsands Provincial Nature Reserve (DNR). This nature reserve is located one kilometre east of Cape Town International Airport, in the Western Cape, South Africa. My analysis of the first theoretical framework (the social construction of nature) confirms that a) the idea of nature is constructed over time; b) nature, as a concept and a phenomenon, is complex; c) nature discourses reveal, hide, and create 'truths' about nature which are accepted as being truthful yet are a question of social struggle and power politics; d) humans have amassed countless definitions of the word 'nature'. Those definitions are categorised by Castree and Braun (2001) into three groups: external, intrinsic, and universal. My analysis of the second theoretical framework (environmental justice) suggests that the idea of nature can be used constructively or negatively depending on who uses it and why. The link between both theoretical frameworks suggests that nature is bound up with agendas. Humans construct natures to pursue individual, social or political agendas. From this standpoint the focus of the thesis shifts from debating whether or not nature is socially constructed to examining what type of agendas were pursued to achieve those 'natural' constructions, and what their consequences were for local communities living in and around protected areas. In order to achieve this, I employed four interlinked analytical methods (stakeholder, discourse, critical and ideological analysis). My analysis of the case study of DNR and that of the history of nature conservation in South Africa suggests ideological similarities. First, in both cases nature conservation is inspired by external environmental views. In the colonial period of South Africa, nature conservation policies and practices were shaped by English and Afrikaner protectionist ideas and aimed also to address the demand of their naturalists, sportsmen, and explorers for hunting and exploiting wild animals. In post-apartheid South Africa, nature has been 12 constructed in protected areas according to universalised environmental views and to some extent has been proactive, meaning that it aimed to address some of the social challenges. Likewise, at DNR, nature conservation was adopted in the early 1980s by the white government to pursue political agendas. In the late 1980s nature conservation began to be influenced by universalised environmental views. Second, the ideological nexus of both discourses regarding nature and local communities suggests conformity with global environmental models. Under these models the normal course is: a) to fence local communities from protected areas or to fence protected areas from local communities, b) to maximise the boundaries of protected areas, or to minimise the settlements of local communities in protected areas, c) to regulate local communities' access to protected areas and natural resources, d) to promote persuasive concepts of ecotourism to achieve nature conservation goals through community participation, co-benefiting local communities from protected areas, co-managing protected areas with local communities, and local socio-economic development, e) to aim for the removal of the on-site communities from protected areas. The impoverishment of the DNR on-site communities has been effected by means of three ideological principles. Since 1990, DNR's on-site communities have been labouring under a state of emergency - the state of living below the flood line; the state of high level of house robbery and a worrying level of rape and child abuse. Their dispossession has led to the spaces of temporality - a state of informality and limited public services and hopelessness (there is no hope of sustaining settlements on the site). Currently, these communities are cornered between two choices. Either they voluntarily relocate their shacks into the surrounding townships or they live with the state of emergency, hopelessness and temporality. Local communities of other protected areas in South Africa have been similarly impoverished by these states of emergency, temporality and hopelessness. During the colonial period, South Africa's conservation discourses were predominantly white-based. Whites constructed the common sense among themselves that they own the land and wildlife. Constructing the idea that they are the people of the land meant also suppressing the non-white sovereignty over land and natural resources. For example, Until late in the twentieth century [South African children's literature in English] 13 usually endorsed the assumption held by whites that they had exclusive ownership of the land and wildlife' (Jenkins, 2004: 107). While whites were protecting South Africa's wildlife, they also alienated blacks from nature. It is just recently, after 1994 that, 'English-Language children's writers and translators of indigenous folktales for children have begun to explore traditional beliefs about and practices in conservation (Jenkins, 2004: 107). These statements do not state or imply that English literature on humannature discourse begun to explore the idea of harmony where indigenous people live and depend on wildlife. In South Africa, it is typical for non-white communities living in or around protected areas to be relocated voluntarily or by force from their land or their settlements, and to be denied resources they had traditionally used within protected areas. Finally, both contemporary discourses continue to be in line with various universalised conservation models. Although both discourses have evolved over time, the status quo of local communities has remained the same: impoverished by exclusion from protected areas, permitted participation in only insignificant co-management models and recipients of intangible benefits. Although the contemporary discourse on nature conservation appears to be more considerate of local communities, I suggest that it is early days for this young discourse to achieve harmony between people and nature. It is up to local and national governmental and non-governmental agencies to modify global environmental views rather than fully adopting them, in order to be more respectful and accommodating of local communities.

This multiproxy study explores the palaeoenvironmental record of two cores, H2 and H7, from the Namaqualand Mudbelt representing an arid and highly variable landscape. As bulk organic radiocarbon ages previously proved problematic, with anomalous reversals, the primary objective was to improve chronology and palaeoenvironmental reconstructions through high resolution 813C, 81SN and pollen analysis, with the aid of principal component analysis. Bulk organic radiocarbon dating of the surface sediment had previously yielded older than expected ages. New 210Pb analysis has established that these surface sediments are modem and radiocarbon ages are now recalibrated to yield an adjusted age of ±3 470 cal yr BP at the base of the more distal core, H7. Pollen spectra correlate well with stable isotopes and include recent disturbance indicators in the Succulent Karoo, Grassland, Karoo expansion, stock farming, impoundment, saltmarsh degradation and increase in domestic cereal cultivation. The proximal and distal mudbelt sites are, however, isotopically distinct, with 813C, inverse nitrogen and C/N ratios characterising H2 as more terrestrial. The excursion towards C3-rich values at around 6m depth in the proximal mudbelt suggests an increase in marine sources and C3 vegetation, while associated pollen aridity indicators implicate reduced inland flooding. This is contrasted against more humid conditions at 420 cm. Stronger upwelling occurred in near-surface distal mudbelt sediment and an influx of the Buffels River sediment flooded the region at ±3470 yr BP, indicating cooler, less arid conditions. 813C studies reveal the Lower Xobies palaeoflood deposit to be less C4-rich than expected, possibly due to sediment source, and is strikingly isotopically similar to the distal mudbelt. The palaeoenvironmental interpretation of the pollen assemblage, isotopes and chronology presents an improved understanding of the region represented in the mudbelt sediments. This corresponds well with established records of the last ±3 500 years and human induced land use change within the Orange River Catchment. Results also highlight the dynamics of the Orange River, which, combined with a highly variable climate, suggest that caution should be exercised to avoid over-interpreting the level at which environmental changes can meaningfully be reconstructed in arid landscapes, particularly those which are subject to sporadic and catastrophic flooding events.

This thesis explores the utility of the MM5 regional climate model iii product big a detailed wind climatology for South Africa in the context of wind power applications. Given the background of limited available computational resources a sophisticated temporal subsetting algorithm is developed and applied. The goal here is to allow a high resolution 18 by 18km simulation to be carried out over only 365 days of historical records (20 March 1996 until 19 March 1997), yet ensure that it is possible to construct a reasonably accurate climatology from such a short time period because it represents the most typical year available. Throughout the research the model's sensitivity towards different boundary layer and cwnulus parametrisations as well as observational and grid nudging is investigated in depth. New error metrics are specifically designed and applied based on 17 reliable lOni weather stations around the country with the specific purpose of evaluating model skill with respect to the wind patterns that are important for wind turbines. An optimal model configuration is established by using the Pleim Xiu land surface scheme coupled with the Atmospheric Convective Model for the planetary boundary layer, in addition to the Kain Fiitsch II cumulus parametrisation and observational wind nudging. The model is then integrated at 18km for the entire country and the results validated in detail. It is found that average wind speeds are within 0.2 + 0.7ms (68% confidence interval) and that the daily cycle, which constitutes the largest part of the observed variance, is predicted to within 18% + 20% of amplitude and lii of timing at coastal sites.

In arid southern Africa, many rivers are ephemeral, and surface flow occurs for less than 10% of the year. Floods, which occur erratically, recharge groundwater resources on which riverine vegetation depends. Trees and shrubs are the most common life forms along these river systems, because surface flows are too erratic for aquatic organisms to flourish. There is concern that alterations to the current water regime of ephemeral rivers will affect the distribution of riparian vegetation as trees provide valuable fodder, shade, firewood and construction material in otherwise inhospitable surroundings. Climate change, population growth and development needs all place growing pressure on these water-limited ecosystems. Careful catchment management is essential to meet human water needs without jeopardising the ecosystems. This is easier said than done however, as ephemeral river ecology and functioning are hardly understood. Their unpredictable hydrology, strong groundwater association, often remote location and the presence of large terrestrial life forms make ephemeral rivers difficult to understand and current âEnvironmental water allocationâ methods for wetter systems are unsuitable. Alternative methods are being developed, but to date they still have a strong emphasis on aquatic life forms and riparian vegetation is still insufficiently addressed. This study provides an ecophysiological perspective on the water sources and drought tolerance levels of four key riparian tree species in Southern Africa. The aim is to contribute to an improved understanding of the interrelationships between river flow, groundwater and use of water by trees. Stable Hydrogen and Oxygen isotope results show that the three key species along the Kuiseb River (Acacia erioloba, Faidherbia albida and Tamarix usneoides) do not take up any water from the regularly occurring fog events. Instead, they depend on a seasonally fluctuating mix of shallow and deep soil moisture as well as groundwater. All these water sources rely on regular recharge from floods. It suggests that reductions in flood frequency and especially in magnitude and duration will reduce groundwater recharge and affect species productivity and survival. It was investigated why A. erioloba, growing in the presence of the alien Prosopis glandulosa, show high mortality rates. The study used stable 2H, 18O and 13C isotopes, xylem pressure potentials and percentage canopy dieback to conclude that within the riparian zone, the two species depend on the same water sources and that indigenous A. erioloba are 2 significantly more water stressed when growing alongside P. glandulosa. Further inland A. erioloba is entirely groundwater dependent while P. glandulosa seasonally switches between water sources. This resource partitioning is advantageous for A. erioloba, which does not display the same levels of water stress as in the riparian zone. An investigation into the physiological structure, including wood density, xylem vessel diameters and xylem vulnerability to cavitation for all four species showed that A. erioloba was structurally the most drought tolerant. This finding corresponded well with its high survival rate in the 1980s Namib drought. In the Kalahari, however, it is still outcompeted by P. glandulosa, suggesting that the invasive species has a competitive edge over A. erioloba that goes beyond xylem structure. P. glandulosa and T. usneoides are similar in structure. F. albida is structurally the most vulnerable of the species, supporting the high mortality rates observed in the 1980âs. Water sourcing using stable Hydrogen and Oxygen isotopes, xylem structure and phenology were compared for three A. erioloba stands with access to different groundwater depths (4 m, 21 m and 56 m). The aim was to determine whether A. erioloba physiology changed proportionally to groundwater depth. Results show that A. erioloba structure and phenology do respond proportionally to groundwater depth, suggesting that A. erioloba can reach deep groundwater, but that this comes at a cost of increased water stress and reduced vitality. Ttrees depending on deep groundwater may thus be closer to a water-induced survival threshold than those growing with access to shallower groundwater. Catchment managers should carefully weigh up the benefits of new water developments relative to potential losses of this ecologically and economically important species. As the final objective and synthesis this study aimed to evaluate if any of the studied species could be used as a bioindicator for tree health in relation to water availability. T. usneoides was previously observed to be less tolerant to drought conditions than F. albida and A. erioloba, while this study has shown F. albida to be structurally the most vulnerable. Hence no bioindicator could be indentified and it is concluded that the determination of drought tolerance and the identification of one or more bioindicator species for future monitoring is a complex matter that needs to include more structural studies and field documentation during drought. 3 Ultimately the use of indicator species and investigations into water sourcing as well as drought tolerance studies should inform catchment management and be included in future assessments of environmental water requirements (EWR) methods and river health. This study concludes that several of the methods applied in this study (shoot growth measurements, percentage canopy dieback, wood density, δ2H, δ18O and δ13C stable isotopes, xylem pressure potentials and xylem vessel diameters) are worth applying in in a EWR in conjunction with groundwater and flood (volume, duration and height) measurements. This will require a shift from a traditionally aquatic outlook to one that is more inclusive of terrestrial ecology. More interdisciplinary cooperation and lateral thinking between aquatic and terrestrial ecologists is crucial, so that the frequency, magnitude, predictability and duration of floods and associated groundwater recharge are assessed in terms of water needs of woody riparian species as well as the associated terrestrial fauna.

Includes bibliographical references (leaves 130-139). / This research project attempts to determine the relative influences of climate, sea level changes and human activities during the period of sediment accumulation in the Noordhoek basin in the southwestern Cape. South Africa. The research relies on lacustrine sedimentary deposits and their compositional changes as evidence of the dynamic depositional environments from which environmental conditions are inferred. Data on spatial changes on land surfaces have also been employed to complement the sedimentary chronology from catchments beyond historic records. Assessment of the extent of human influence on the Noordhoek basin has been achieved through comparison with the pristine conditions found on the Cape Nature Reserve. Analysis of dated sediment cores from the Noordhoek valley and the Cape Peninsula Nature reserve has facilitated the reconstruction of major environmental changes for the late Pleistocene and Holocene periods. An extended record of environmental change from the longest core (LM-Core) has enabled environmental reconstruction and the determination of the relative influences of climate, sea level change and human activities on the local! environment of the basin during the late Quaternary. Sedimentological evidence from the cores reveals the long-term evolution of the wetlands as being influenced by fluctuating sea levels and climate change until the mid-Holocene. Short-term environmental processes during the late Holocene. resulting from direct anthropogenic activities such as irrational uses of the wetlands for agriculture and urbanisation are responsible for polluting and transforming the status of the wetlands. Heavy metal concentrations in sediment cores from the two Noordhoek wetlands have allowed the elucidation of recent human impacts. The vertical distribution of these metals correlates with and complements the evidence of spatial changes in land use and land cover. Metal enrichment in the modern Noordhoek wetland sediments and increased organic matter content indicates increasing anthropogenic impacts on the valley as agriculture and urbanisation increased. In comparison. there is a much lower concentration of heavy metals at Groot Rondevlei, as its catchment has been less prone to severe local disturbance such as urban development and recent agricultural activities. The absence of a tightly resolved chronology for these cores restricts the understanding of the commencement and duration of major environmental changes, which have been accounted for elsewhere in the region. This limits the opportunity for direct comparison between this and other known sites. However, the Noordhoek valley is a potential resource for longer-term Quaternary environmental study. The application of a multi-disciplinary approach and high-resolution dating are highly recommended for future research in this area.