The Karoo-aged basins evolved from assembly to break-up of the supercontinent Gondwana and were filled by denudating major mountain ranges accompanied by vast sedimentary recycling processes. A succession of rift episodes caused the emergence of a great number of these intra-cratonic basins throughout the Gondwana interior, e.g. the Aranos, Karasburg and Huab basins, which are scattered across today’s Namibia. This evolution may be split into a Permian to early Triassic and a Jurassic phase. The Karoo I phase is confined by ‘passive’ continental rifting and a retro-arc extension at the SW margin of Gondwana. The early Jurassic Karoo II rifting phase of east Africa eventually disintegrated Gondwana and led to the opening of the West Indian Ocean. A terminal early Cretaceous rifting phase led towards the opening of the southern Atlantic Ocean and ended the Gondwana supercontinent sedimentary regime. In the course of this evolution, the Namibian late Paleozoic to Mesozoic sedimentary record yields evidence for changing climates from icehouse towards extreme hothouse conditions. As based on sporadic datings the timeline of this evolution remains mostly unclear. The lack of data is in great contrast to the importance of determining the speed of major climate changes. In addition, sediment fluxes within such a supercontinent regime are not well studied but are key in understanding sediment dynamics during severe ecological and environmental changes. Therefore, this thesis tries to establish a timeframe of the sedimentary deposits for the Namibian Karoo Supergroup sedimentary deposits and furthermore tries to explore the laws of sediment dispersal prevailing in southern Gondwana. In order to answer these research questions a comprehensive dataset comprised of 41 samples with more than 5.700 U-Th-Pb LA-ICP-MS age determinations and over 1.000 Lu-Hf isotopic measurements on single zircon grains of siliciclastic rock material of the vast majority of all Permo- Carboniferous to early Cretaceous Karoo-aged Namibian formations was compiled. All of the investigated zircon crystals were also studied with respect to their grain morphology, including length, width, surface, and roundness, providing valuable information concerning transport distances and energies. In combination with whole-rock geochemical data of a majority of the investigated samples, they help deciphering the sedimentary deposition history during the Gondwana supercontinent cycle. A compiled set of southern African U-Th-Pb zircon age data is of great help interpreting sediment fluxes and inferring provenance areas. The onset of Karoo-aged sedimentation is recorded within the Aranos and Karasburg Basin successions and is represented by glacially induced diamictites of the Dwyka Group partially resting directly on pre-Cambrian basement complexes. In places, two distinct E-W directed ice advances are present. The deposition of these glacial diamictites was prior to 296 Ma, as two ash beds incorporated within the overlying shale successions yield Asselian deposition ages. Further hints concerning ice-induced deposition disappear at the Sakmarian-Artinskian boundary, as the lowermost succession of the Ecca Group yields a maximum deposition age of ca. 290 Ma, documenting the end of the Dwyka ice age in the southern Namibian area. The lowermost Ecca Group deposits of the Huab Basin yield a maximum deposition age of ca. 295 Ma, suggesting an earlier termination of the Dwyka ice age in the north. The uppermost strata of the Aranos and Karasburg Basins were dated ca. 265 Ma and 255 Ma, respectively, revealing a disparate depositional history. Due to a lack of datable ash beds as well as no detrital zircon grain ages near the assumed sedimentation age it was not possible to determine a detailed sedimentation history for the Huab, Kunene River, and Waterberg Basin deposits. Detrital zircon U-Th-Pb ages are routinely used in order to trace siliciclastic sedimentary rocks to their bedrock sources, deriving transport directions. This classic ‘source-to-sink’ approach is most likely obscured by several cycles of sediment homogenization processes. A majority of all investigated samples yield high portions of detrital zircon fractions of late Mesoproterozoic (950-1150 Ma) and Neoproterozoic (440-650 Ma) age. In addition, all Jurassic and Cretaceous samples yield a prominent Permian age fraction of 250-280 Ma, suggesting a Gondwanides orogen provenance. Thus, the investigated siliciclastic rocks consist of already recycled sedimentary material. This observation is supported by a high degree of zircon grain roundness. As of zircon grain hardness long transport distances are necessary to achieve latter. This suggests that one sedimentary sink is source for the next sedimentary cycle. A comparison with the detrital zircon record of other southern Gondwanan Permo-Carboniferous successions shows similar results, strongly pointing towards a supercontinent-wide sedimentary recycling regime. Therefore, detrital zircon age patterns within supercontinent scenarios reflect large-scale sedimentary processes rather than primary provenance information.:1 Introduction 1 1.1 Evolution of the Namibian landscape from Carboniferous to Cretaceous times 2 1.2 Thesis format 5 1.3 References 5 2 Methods 10 2.1 Sample preparation and zircon morphometrics 10 2.2 U-Th-Pb age determination 10 2.3 Lu-Hf model age determination via LA-(MC)-ICP-MS 12 2.4 Geochemical analysis 12 2.5 Comparative statistics 12 2.6 References 13 3 Study I: The Permo-Carboniferous Dwyka Group of the Aranos Basin (Namibia) – How detrital zircons help understanding sedimentary recycling during a major glaciation 15 3.1 Introduction 17 3.2 Regional geological setting 17 3.2.1 Geology of the Permo-Carboniferous Dwyka Group (Aranos Basin) 19 3.2.2 Paleotectonic significance of the Dwyka formations 22 3.3 Methods 24 3.4 Results 26 3.5 Discussion 30 3.5.1 Significance of zircon morphologies for sediment fluxes 32 3.5.2 Potential sedimentation rates and source areas indicated by U-Pb age data 35 3.5.3 Implications for the evolution of the Dwyka Group 42 3.6 Conclusions 46 3.7 References 47 4 Study II: The evolution of the southern Namibian Karoo-aged basins: Implications from detrital zircon geochronologic and geochemistry data 63 4.1 Introduction 64 4.2 Geology of the Aranos and Karasburg basins 66 4.3 Tectonic and structural framework of the southern African Karoo aged basins 70 4.4 Methods 71 4.5 Results 75 4.6 Discussion 80 4.6.1 Timing of the Formation of the Aranos and Karasburg basins 80 4.6.2 Provenance and evolution of the upper Paleozoic Aranos and Karasburg basins 85 4.6.3 Implications for the Karoo-aged basin sedimentary record 93 4.7 Conclusions 95 4.8 References 98 5 Study III: Mesozoic deposits of SW Gondwana (Namibia): Unravelling Gondwanan sedimentary dispersion drivers by detrital zircon 109 5.1 Introduction 110 5.2 Geological background 113 5.2.1 Evolution of the southwestern Gondwanan Mesozoic successions 113 5.2.2 Namibian Mesozoic successions 117 5.3 Methods 120 5.4 Results 123 5.5 Discussion 130 5.5.1 Protosources of the sediments 130 5.5.2 Recycling dynamics of the Mesozoic sediments 133 5.6 Conclusions 139 5.7 References 140 6 Study IV: Tracing southern Gondwanan sedimentary paths: A case study of northern Namibian Karoo-aged sedimentary rocks 153 6.1 Introduction 154 6.2 Geological setting 156 6.2.1 SW Gondwanan rifting history and sediment dispersal 156 6.2.2 The northern Namibian Karoo-aged Huab Basin and Kunene section 157 6.3 Methods 161 6.4 Results 165 6.5 Discussion 175 6.5.1 Timing of deposition of the Huab Basin strata 175 6.5.2 Protosources of the sediments 176 6.5.3 Detrital zircon grain morphology and isotope analysis 178 6.5.4 The northern Namibian Karoo-aged basins within the southern Gondwanan framework 185 6.6 Conclusions 186 6.7 References 187 7 Conclusions and outlook 199 8 Supplements 201

Leopards (Panthera pardus) are the most common large predators, free roaming outside of protected areas across most of South Africa. Leopard persistence is attributed to their tolerance of rugged terrain that is subject to less development pressure, as well as their cryptic behaviour. Nevertheless, existing leopard populations are threatened indirectly by ongoing transformation of natural habitat and directly through hunting and conflict with livestock farmers. Together these threats may further isolate leopards to fragmented areas of core natural habitat. I studied leopard habitat preferences, population density, diet and the attitudes of landowners towards leopards in the Little Karoo, Western Cape, South Africa, an area of mixed land-use that contains elements of three overlapping global biodiversity hotspots. Data were gathered between 2010 and 2012 using camera traps set up at 141 sites over an area of ~3100km², GPS tracking collars fitted to three male leopards, scat samples (n=76), interviews with landowners (n=53) analysed in combination with geographical information system (GIS) layers. My results reveal that leopards preferred rugged, mountainous terrain of intermediate elevation, avoiding low-lying, open areas where human disturbance was generally greater. Despite relatively un-fragmented habitat within my study area, the leopard population density (0.75 leopards/100km²) was one of the lowest yet recorded in South Africa. This may reflect low prey densities in mountain refuges in addition to historical human persecution in the area. Currently local landowners are more tolerant of leopards than other wildlife species with incidents of conflict involving leopards being rare relative to black-backed jackals (Canis mesomelas), baboons (Papio hamadryas), caracals (Caracal caracal) and porcupine (Hystrix africaeaustralis). Although current levels of conflict between leopards and stock farmers are low, leopards do depredate livestock, which constitute 10-15% of their diet. Improved livestock husbandry measures and co-operation between conservation authorities and farmers are necessary to mitigate such conflict and balance economic security with biodiversity conservation in the region. Leopards are the only remaining top predators throughout much of the Little Karoo and the Western Cape and as such are predicted to play a critical role in ecosystem structure and the survival of other species. Current high levels of connectivity between areas of suitable leopard habitat bode well for the conservation status of leopards within this region and future conservation efforts need to ensure that narrow corridors linking such habitat are preserved. The potential for leopards to serve as both an umbrella and a flagship species for biodiversity conservation suggests that long term monitoring of this population would be a conservation priority for the Little Karoo.

The Little Karoo, situated in the Succulent Karoo biome of South Africa, has been heavily transformed by land use, and only 8.6% of the remaining natural vegetation is considered to be intact. There is ample evidence that the main cause of degradation is the overstocking of ostriches, an industry that has been the major economic driver of the area for more than 150 years. The ostrich stocking rate currently recommended is 22 ha.ostrich⁻¹. A literature review was used to examine the evidence, assumptions and rationale on which recommended and actually implemented stocking rates for ostriches are based. No experimental evidence using ostriches was found that supported the recommended stocking rate as either ecologically or economically sustainable. From the literature, there appears to be a wide gap between what are considered to be economically and ecologically sustainable stocking rates, with the implication that these two aims may be impossible to reconcile when practicing ostrich farming on natural veld. A comparison of recommended with actual stocking rates among land managers in the Little Karoo showed that all land managers far exceeded the recommended agricultural stocking rate of 22.8 ha.ostrich⁻¹. However, the stocking rates reported by land managers to the South African Ostrich Business Chamber were found to accurately reflect actual numbers determined when whole flocks had to be slaughtered after an outbreak of avian influenza. The recommended stocking rate appeared to be irrelevant to ostrich flock breeders and there appeared to be a trade-off between profitable ostrich farming and sustainable land-use practices. This study also investigated the attitudes and behaviour of ostrich farmers. It was found that environmental attitude is most likely the most important characteristic of a land manager to ensure positive conservation behaviour. This characteristic was most prominent in younger land managers with larger farms. The last component of the study integrated the context and complexity of the long term social, economic and ecological sustainability of this industry through the development of a logic model. The results showed a general lack of linkages between industry elements which impact on achieving sustainability targets. Greater collaboration between industry role-players, organized agriculture and conservation organizations is required to find a balance between utilization and conservation in the ostrich industry.

Thesis (MScAgric (Agricultural Economics))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Before the ostrich industry started in the Klein Karoo region of South Africa in 1863, the veld was used mainly for large and small stock production. Returns per hectare (ha) from large and small stock production are low due to the low carrying capacity of the veld in this region. However, when the veld is utilised predominantly to provide space for breeding ostriches sustained mainly by lucerne-based feed supplements, the limited-feed production capacity no longer determines the long-term stocking rate. The returns, per ha, from ostrich production can therefore be much higher than from sheep, goats and cattle. This has resulted in high ostrich stocking rates, which in turn, has caused degradation to most of the veld to a greater or lesser extent. Driven by a personal conviction to manage the veld sustainably, as well as by a fear of environmental damage connotations for ostrich leather products, which could restrict market access, ostrich farmers in the Klein Karoo, represented by the South African Ostrich Business Chamber (SAOBC), increasingly place an emphasis on veld restoration. The various phases of ostrich production are breeding and hatching eggs to produce day-old chicks, rearing chicks, raising birds, and the final phase of weight addition to slaughter. The phase that is considered in this study is the production of day-old chicks. There are two systems that can be used for producing day-old ostrich chicks, namely, the flock breeding system and the small-camp system. Shifting from the flock breeding system to the smallcamp system will enable the farmer to practice genetic selection. This switch from the flock breeding system to the small-camp system requires the farmer to invest in fencing material. The SAOBC requested a study to determine whether the expected private benefits from moving breeding ostriches to small camps in order to free up the large veld camps for veld restoration would justify investing in these small camps. If this investment is not financially justified, the veld restoration will have to be financed via payment for ecosystem services. Both passive and active veld restoration techniques are considered in this study. Passive restoration requires the farmer to invest in fencing material needed for the erection of the small camps. Active restoration requires the farmer to invest not only in fencing material, but also in soil manipulation and seeding. The main aim of this study is to find out if the private (financial) benefits from the switch to small camps can compensate for fencing costs, without the cost of active restoration, or if the switch to small camps can compensate for fencing costs with the cost of active restoration. Typical farm models were developed for this purpose, and the results showed that the private benefits compensate for the investment cost of fencing material used for passive restoration as well as for restoration of 10% of the veld that is heavily degraded. When the full cost of active restoration of the moderately degraded veld (30%) was added, the private benefits could not compensate for the full restoration cost. / AFRIKAANSE OPSOMMING: Voordat die volstruisbedryf in 1863 in die Klein Karoo ontstaan het, is die veld hoofsaaklik gebruik vir groot- en kleinveeproduksie. Die wins per hektaar van groot- en kleinvee produksie in hierdie streek is laag weens die lae drakrag van veld. Wanneer die veld egter primêr aangewend word vir ruimte vir volstruise wat met lusern gebaseerde rantsoene gevoer word, bepaal die natuurlike drakrag nie meer die belading met volstruise oor die langer termyn nie. Die wins per hektaar uit volstruisboerdery kan dus veel hoër wees as wat met skape, bokke of beeste gegenereer kan word. Dit het hoë belading met volstruise tot gevolg gehad wat vernieling van meeste van die veld tot gevolg gehad het. Gedryf deur persoonlike oortuiging om die veld volhoubaar te benut, sowel as deur vrees dat die vernielde veld die beeld van die volstruisbedryf mag skaad en internasionle marktoegang mag belemmer, het volstruisprodusente in die Klein Karoo, verteenwoordig deur die Suid-Afrikaanse Volstruisbesigheidskamer (SAVBK), toenemend klem begin plaas op veldrestorasie. Die verskillende fases van volstruisproduksie sluit in teling en uitbroei van eiers om dagoud kuikens te lewer, kuikens grootmaak, voëls grootmaak en massa toename tot by slag. Die verskillende fases word dikwels deur verskillende produsente behartig. Die fase waarop in hierdie ondersoek gefokus word is die produksie van dagoud kuikens. Daar bestaan twee stelsels vir die produksie van dagoud kuikens, naamlik tropparing en die kleinkamp stelsel. Die oorskakeling van tropparing na die kleinkamp stelsel stel die produsent in staat om genetiese seleksie toe te pas, maar dit verg investering in omheiningsmateriaal. Die SAVBK het ‘n ondersoek aangevra om te bepaal of die verwagte privaat voordele wat verkry kan word uit die oorskakeling na die kleinkamp stelsel om veldrestorasie moontlik te maak, die investering in die kleinkampe sal regverdig. Indien die investering nie finansieel geregverdig kan word nie, sal verder gekyk moet word na finansiering vanuit betaling vir ekostelsel dienste wat moontlik bevorder kan word deur die veldrestorasie. Die koste van beide passiewe en aktiewe veldrestorasie tegnieke word in hierdie ondersoek gedek. Passiewe restorasie vereis alleen van die produsent om te investeer in omheiningsmateriaal vir kleinkampe. Aktiewe restorasie vereis investering in omheiningsmateriaal vir kleinkampe en betaling vir grondmanipulasie en saad vir die hervestiging van plante. Die doel van die ondersoek is om te bepaal of die privaat (finansiële) voordele van die oorskakeling na kleinkampe kan kompenseer vir die investering in omheiningsmateriaal met aktiewe veldrestorasie en sonder aktiewe veldrestorasie (dus passiewe restorasie). Tipiese plaasmodelle is hiervoor ontwikkel. Die resultate toon dat die privaat voordele wel kan kompenseer vir die omheiningskoste van kleinkampe benodig vir passiewe restorasie en vir aktiewe restorasie van 10% van die veld wat die meeste verniel is. Wanneer die koste van restorasie van 30% van die veld wat matig verniel is, bygevoeg word, is die privaat voordele ontoereikend om die totale restorasiekoste te dek.

Thesis (MSc)--Stellenbosch University, 2013. / This study presents a facies outcrop characterization and petrographical analysis of Unit B of the Permian Laingsburg Formation. Unit B is interpreted as a base-ofslope system, which represents a strikingly sand-rich succession. The base-of-slope system is defined by a channel-levee complex. The study provides systematically a clear understanding and description on reservoir heterogeneities, in terms of facies distribution, physical processes and architectural elements. The dataset included detailed sedimentary logs, photomosaic interpretations, supplemented by a petrographical study to determine the textural and compositional attributes of the studied sandstones. Seven lithofacies was recognised within Unit B, based on detail observation and description on grain size and sedimentary structures. They mainly consist of 1) thick to massive bedded ‘structureless’ sandstone, 2) horizontal and ripple cross-laminated thin-medium bedded sandstone, 3) silty sandstone, 4) structureless siltstone, 5) hemipelagic mudstone, 6) muddy slump, and 7) sandy slump. Palaeocurrent analysis indicates that the mean sediment transport direction of Unit B was to the E and NE. Lithofacies 1 comprises thickly to massive bedded, frequently amalgamated, mostly very-fined grained sand, mixed grading, irregular to sharp upper contacts, structured upper bedding planes, large floating mudstone clasts and granules, rare groove and flute casts. Also, scour and fill features have been documented. Lithofacies 1 has been interpreted to result from channelized sandy debris flow currents. Lithofacies 2 composes of thin-medium bedded, very fine-grained sand, ungraded, sharp upper contacts, discrete units with traction bed forms, horizontal and cross-lamination, mud-draped ripples, internal erosional surfaces and preserved crests. Lithofacies 2 shows diagnostic sedimentary features for a deep-water bottom reworking current. Lithofacies 5 composes of very fine–grained mud, ‘structureless’ to finely horizontally laminated, fissile mudstone. Deposition resulted from suspension settling of mud fractions out of a low-energy buoyant plume. Lithofacies 6 composes of contorted and convoluted bedding, steeply dipping layers and irregular upper contacts. Deposition occurred via slumping on an unstable slope. Lithofacies 7 composes of fine–grained ‘structureless’ sandstone, amalgamated units, with dark floating mudstone granules. Lithofacies 7 has been interpreted to form from channelized flows evolving into slump deposition on an unstable slope. The petrographic data reveals that the reservoir quality of the sandstones is strongly controlled by depositional processes and diagenetic products. The sediments of the Karoo Basin appear to be diagenetically controlled as a function of burial depth. The major diagenetic products controlling the reservoir quality of the sandstones, includes compaction (mechanical and chemical), and authigenic porefilling constituents (quartz cement, feldspar dissolution and partial to complete replacement, calcite cement, chlorite and illite). Compaction played a major role in the evolution of the sediment, as compared to the effect of quartz cementation, and is considered here to have caused irreversible destruction of depositional porosity and permeability. The sediment has undergone intense mechanical compaction during early-stage diagenesis, low temperature and shallow depth of burial (probably the first 2 km). The high burial palaeotemperature (250 ± 500C) or more specifically the high geothermal gradient of the Karoo Basin consequently increased the number of diagenetic reactions. The high burial temperatures may have increased pressure dissolution and quartz cementation. With compaction been limited, quartz cementation and the authigenesis of chlorite and illite at deeper depths may have had a profound effect on the permeability distribution of the studied sandstones. After the completion of diagenesis, the pore systems of these sandstones were completely destroyed by low-grade regional burial metamorphism.

Thesis (MA)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Since its arrival onto the U.S. energy scene in the early 2000s, shale gas has had a significant impact on the global energy market. The fact that the shale gas supply of a single country has had such a widespread influence on the global energy market hints at the power that this energy resource holds as a ‘game changer’. With the fifth largest estimated shale gas reserves in the world, South Africa now faces the challenge of developing its own shale gas resources in the Karoo Basin. Having lifted the moratorium on hydraulic fracturing in September 2012, the South African government has indicated its interest in pursuing the commercial extraction of the country’s estimated shale gas reserves. This comes in light of the country’s potential energy crisis, as well as an increased role for natural gas in the country’s energy mix. South Africa has no history of shale gas extraction and currently has no legislation or regulatory practices in place to deal specifically with shale gas and hydraulic fracturing. The South African government thus faces the challenge of drawing policy lessons from other experienced shale gas-producing nations, such as the U.S., to close these regulatory gaps and exploit its national shale gas resources in an environmentally and economically responsible way. Consequently, this thesis focuses on the regulation of the American shale gas industry by asking what policy lessons the South African government can draw from the United States of America on its regulation of shale gas extraction. Richard Rose’s lesson-drawing approach to policy learning was adopted as the theoretical framework for this study and can also be applied as an analytical tool to aid in data collection and data analysis. Furthermore, the framework was operationalised through the research methods used for this case study, which consisted of a review of literature on the U.S. regulation of shale gas extraction. This research produced a number of key findings in the form of policy lessons for South Africa. Four main policy lessons were drawn on the regulation of shale gas extraction: regulation of shale gas extraction must occur at all levels of government—national, provincial and local; policy research must be used to inform policymaking for the development of new legislation specific to shale gas and hydraulic fracturing, so as to avoid regulatory exemptions often linked to ad hoc policymaking on shale gas extraction; each level of government and their related regulatory agencies must have clearly defined regulatory roles relating to shale gas and hydraulic fracturing; and finally, there must be uniformity in terms of the regulatory focus of shale gas regulators at all levels of government. / AFRIKAANSE OPSOMMING: Sedert skaliegas vroeg in die jare sedert 2000 op die Amerikaanse energietoneel verskyn het, het dit ‘n beduidende impak op die globale energiemark gehad. Die feit dat die voorraad skaliegas van een land so ‘n wydverspreide invloed gehad het op die globale energiemark is ‘n aanduiding van die mag van hierdie energiebron as ‘n spel-wisselaar.Suid-Afrika het die vyfde-grootste skaliegasreserwes ter wêreld, en staan nou voor die uitdaging om sy eie skaliegasreserwes in die Karookom te ontwikkel. Nadat die moratorium op hidrobreking in September 2012 opgehef is, het die Suid-Afrikaanse regering aangedui dat hulle belangstel om die land se beraamde skaliegasreserwes kommersieel te ontgin. Dit het ontstaan in die lig van die potensiële energiekrisis wat Suid-Afrika in die gesig staar, asook die begeerte dat aardgas ‘n groter rol moet speel in die land se mengsel van energiebronne. Suid-Afrika het geen geskiedenis van skaliegasontginning nie en tans is daar geen wetgewing of regulerende praktyke in plek wat spesifiek te make het met skaliegas en hidrobreking nie. Die Suid-Afrikaanse regering staan dus voor die uitdaging om te leer uit die beleidsrigtings van ander ervare skaliegaslande soos die V.S.A. ten einde hierdie leemtes in regulering op te hef en sy nasionale skaliegasreserwes op ‘n omgewingsvriendelike en ekonomies-verantwoordelike manier te ontgin. Gevolglik fokus hierdie tesis op die regulering van die Amerikaanse skaliegas-industrie deur te vra watter beleidslesse die Suid-Afrikaanse regering kan leer by die Amerikaanse regering oor die regulering van hulle skaliegasontginning. Richard Rose se 'lesson-drawing'-benadering tot die leer van beleid is aanvaar as die teoretiese raamwerk vir hierdie studie en kan ook aangewend word as 'n analitiese instrument om te help met dataversameling en -analise. Die raamwerk is verder geoperasionaliseer deur die navorsingsmetodes wat gebruik is vir hierdie gevallestudie, wat bestaan het uit 'n oorsig van die literatuur oor die V.S.A. se regulering van skaliegasontginning. Hierdie navorsing het ‘n aantal sleutelbevindinge opgelewer in terme van beleidslesse vir Suid-Afrika. Die vier vernaamste beleidslesse oor die regulering van skaliegasontginning wat na vore gekom het, is die volgende: die regulering van skaliegas moet op alle vlakke van regering geskied – nasionaal, provinsiaal en op plaaslike vlak; navorsing oor beleid moet gebruik word om beleidsvorming in te lig sodat nuwe wetgewing ontwikkel kan word wat spesifiek gerig is op skaliegas en hidrobreking, ten einde uitsonderings op regulering te voorkom wat dikwels verbind word met ad hoc beleidsformulering; elke vlak van regering en sy verwante reguleringsagentskappe moet duidelik gedefinieerde reguleringsrolle hê ten opsigte van skaliegas en hidrobreking; en, ten slotte, daar moet eenvormigheid wees in die reguleringsfokus van skaliegasreguleerders op alle vlakke van regering. / National Research Foundation (DAAD-NRF)

Thesis (MScConsEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2005. / The veld condition in the Little Karoo is in various states of degradation and grazing by domestic livestock is considered as the major anthropogenic force that changed the landscape. This region with its extremely rich plant species diversity and endemics, has supported small livestock for at least 2 000 years, and since colonization (250 years ago) been intensively used for the production of a variety of livestock. Ostrich production developed as the major source of income for this region. The first part of this study investigates the current veld management practices employed by livestock farmers in the Little Karoo region. Recommended veld management practices considered in this study are grazing rotation, moderate stocking rate control, moderate veld utilisation, separation of ecotopes, veld rehabilitation, controlling declared weeds and alien vegetation and regular assessment of veld condition. One hundred randomly selected farmers were personally interviewed by means of a structured questionnaire. Questions were grouped into the following categories: (a) demography of farmers, (b) ostrich farming, (c) perceptions and knowledge of farmers on farming practices, (d) grazing rotation, (e) stocking rate, (f) veld utilisation and veld assessment, (g) separation of ecotopes, (h) veld rehabilitation, (i) control of alien vegetation and (j) farmers’ knowledge on legislation. This was used to obtain information on the Little Karoo farming community, sizes of farms and camps, types of farming enterprises and on adoption of recommended veld management practices in the region. The main findings from this section are that relatively small farming units with few camps, poor separation of ecotopes and a low estimated grazing capacity, limit extensive livestock farming within the region. Perceptions of farmers on veld condition, grazing rotation, stocking rate, separation of ecotopes are fairly optimistic. As a result grazing capacities are overestimated and overstocking occurs within this region. The current stocking rate in ostrich camps (67.7% overstocked) and mammalian livestock camps (55.1% overstocked) is evidence that farmers overstock to compensate for these limiting factors in order to make a living from the land. The majority of farmers are well aware of the Articles in the Conservation of Agricultural Resources Act of 1983, which are applicable to veld management. Only more that 50% comply with this legislation by rehabilitating veld and 80% of them control invasive alien species on their farm. In the second part, veld assessments were done in randomly selected veld camps, using the multi-criterion, semi-subjective Quick Rangeland Health Assessment (QRHA) Method. Veld condition was significantly poorer closer to water or feeding points due to the piosphere effect caused by livestock. Veld condition in the Little Karoo can be related to altitude, vegetation types and land use. Therefore, the lowlying Little Succulent Karoo vegetation type is in a poorer condition compared to Spekboom Succulent Thicket and South and South-west Coast Renosterveld. Ostrich production on plains in the Little Succulent Karoo vegetation type is the main cause for the degradation of this vegetation type. It would seem as if historically high stocking rates cannot be ignored in explaining the current veld condition. A positive correlation between veld condition and the diversity of plant species (species density) were found, which highlights the importance of good veld management practices in sustainable agriculture. The third part tested whether all indicators in the QRHA method are equally sensitive and whether there is a positive correlation between the QRHA method and the Grazing Index Method. A significant positive linear correlation was found between the two methods. Cover was the least sensitive indicator of rangeland condition, and livestock induced disturbances (which include the indicators grazing intensity, disturbance indicators, soil health and species richness) were the most sensitive for Karoo veld assessment. A major benefit of the QRHA method is heuristic; therefore this method may have value in agricultural extension work.

Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol) / Due to their popularity for tourism, giraffes are being introduced into Thicket areas within the Little Karoo region of the Western Cape. However, information regarding the activity budgets and diet selection of these giraffes is lacking. Therefore, this study aimed to achieve three objectives; to determine the diurnal activity budget, diet composition and browsing levels, and the estimated browsing capacities of extralimital giraffe. The study was conducted on two privately owned farms, namely Kareesbos Private Game Reserve and Tsumkwe Private Game Reserves. Observations were completed on both study sites using the interval scan method, whereby observations were conducted on all visible individuals from 6 am – 6 pm for four days every 3 months (winter, spring, summer and autumn). Observations found browsing to be the most dominant activity displayed by both populations, with walking and rumination being the second and third most dominant activity. Females browsed more than males in both study sites. Dietary observations showed four species (Pappea capensis, Portulacaria afra, Euclea undulata and Searsia longispina) and five species (Searsia longispina, Euclea undulata, Pappea capensis, Vachellia karroo and Grewia robusta) to comprise approximately 90% and 80% of their diet in Kareesbos and Tsumkwe respectively. The importance of flower bearing species (Lycium spp. and Rhigozhum obovatum) increased during the spring and summer seasons in both study sites. In addition to the diet selection, browsing by both giraffe populations was shown to occur mostly below 2 m. Estimated browsing capacities for Kareesbos and Tsumkwe were 25 and 21, and 107 and 88 ha per giraffe, respectively, for the respective browse height strata of less than two metres and five metres. It is suggested that browsing capacities of less than two metres be considered when stocking giraffe and the number of individuals adjusted accordingly on each farm, due to the continuous low browsing of giraffe at less than two metres. Furthermore, results indicate that these giraffes have adapted to take advantage of forage available in ecosystems outside their natural ranges. Low foraging heights suggests possible niche overlap with other browsers, which may result in increased competition for food when it becomes limited. Long term ecological monitoring of extralimital populations and appropriate management procedures are therefore required to avoid the displacement and degradation of indigenous fauna and flora within the Little Karoo, and possible mortalities amongst the giraffe populations.

Magister Artium - MA / Changes in climate patterns have raised concerns for environmentalists globally and across southern Africa. The changes greatly affect the growth dynamics of vegetation to such an extent that climate elements such as rainfall have become the most important determinant of vegetation growth. In arid and semi-arid environments, vegetation relies on near-surface groundwater as the main source of water. Changes in the environment due to climate can be examined by using remotely sensed data. This approach offers an affordable and easy means of monitoring the impact of climate variability on vegetation growth. This study examined the response of vegetation to rainfall and temperature, and assessed the dependence thereof on groundwater in a climatically variable region of the semi-arid Karoo. The methodology used included sampling plant species in the riparian and non-riparian areas over two plant communities in seven vegetation plots. The Normalised Difference Vegetation Index (NDVI) derived from the Landsat OLI and TM was used to measure vegetation productivity. This was compared with rainfall totals derived from the Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) and the mean monthly temperature totals. A drought index, (Standardised Precipitation Index – SPI) was an additional analysis to investigate rainfall variability. Object-based Image Analysis (OBIA) and Maximum Likelihood supervised classification approaches together with indicators of groundwater discharge areas (Topographic Wetness Index – TWI, and profile curvature) were used to map vegetation and surface water that depend on groundwater.

The Main Karoo Basin of South Africa is renowned for its exceptional palaeontological record and while its vertebrate fossils have been extensively researched, Karoo floras have received considerably less attention. Poor yields of palynomorphs from the Beaufort and “Stormberg” groups have complicated the task of erecting a comprehensive palynozonation scheme for the Karoo Supergroup. For this study, 65 palynologically productive samples from the Dwyka, Ecca, Beaufort and “Stormberg” groups allowed for systematic descriptions of all palynomorphs, as well as the ranges of the different taxa through the entire Karoo stratigraphic succession. Taxa with restricted ranges are useful for biostratigraphic correlation and these palynomorphs were used to delineate microfloral zones for the Karoo basin. The Dwyka Group contains high numbers of acritarchs and is generally low in species diversity. Useful biostratigraphic taxa for the Ecca Group include Cannanoropollis, Hamiapollenites, Platysaccus and Striatopodocarpites. Aratrisporites is a marker for the Latest Permian / Early Triassic Beaufort Group, while Cyathidites, Dictyophyllidites, Equisetosporites and Uvaesporites are indicators of the Late Triassic / Early Jurassic “Stormberg” Group. Palynostratigraphic zones correlate largely with the Karoo vertebrate biozones and severe and sudden extinction events are recognised among Karoo palynomorphs in the upper Tapinocephalus and Dicynodon assemblage zones. The first comprehensive palynological biozonation scheme for the Main Karoo Basin is proposed and the study provides a broad overview of Gondwanan Carboniferous - Jurassic floras. This study demonstrates that palynology is useful in correlating age equivalent lithostratigraphic units in the proximal and distal sectors of the Karoo Basin. Microfloras from previous South African studies are integrated within the proposed palynostratigraphic scheme, and palynological signatures of the various Karoo formations are shown to be consistent. Despite the constraints of floral provincialism, South African microfloras can be correlated to selected Gondwanan biozonations from Australia, Africa, Antarctica, New Zealand and South America. Future studies should focus on sampling more intensively over smaller stratigraphic intervals, which will assist in the correlation of time equivalent lithostratigraphic units in the different sectors of the basin, thus aiding in refinement of basin development models. Key words: palynology, Karoo, vertebrate biozones, stratigraphy, Gondwana