The semi-arid forms of subtropical thicket in the Eastern and Western Cape have been heavily degraded through unsustainable pastoralism over the last century or more. The degraded areas exhibit a significant loss of above-ground and belowground carbon stocks, and consequently provide an opportunity for restoration through the formal and informal carbon markets. A prerequisite for the attainment of carbon credits is to ensure sound carbon stock baselines prior to effecting restoration. I report on the carbon stocks (including sub-pools) for a number of intact subtropical thicket types, as well as the differentials between the intact and degraded states (including the sub-pools). Total carbon stocks (TCS in t C ha⁻¹) for intact vegetation (to a soil depth 0–25 cm), ranged from 87.73±6.51 to 70.64±17.24. For degraded vegetation (including old lands), TCS (t C ha⁻¹) ranged from 34.05±3.61 to 21.03±2.70. For all vegetation types, the differentials in TCS along the degradation gradient (0–25 cm) are highly significant and strengthen the possibility for carbon credit financing to catalyse the restoration of the degraded semi-arid subtropical thickets. This study has shown a mean loss of 57.23 t C ha⁻¹ in Baviaanskloof spekboom thickets, when measured to a soil depth of 25 cm. Portulacaria afra is a key species within the semi-arid subtropical thickets, being a canopy dominant and a driver of soil nutrient status, but has been largely lost from the degraded landscapes. Degraded semi-arid subtropical thicket vegetation lacks regeneration via seedling recruitment; restoration therefore requires the manual replanting of P. afra using cut truncheons. Survivorship trials were undertaken infield in 2005 to establish restoration protocols for P. afra, with survivorship being recorded in 2006 and 2008. Overall survivorship for all treatments was found to be 43.2±2.8% in 2006, dropping to 35.8±2.7% in 2008. Planting posture (flat or upright) showed the most significant results of all the factors tested in 2006 and 2008. Micro-damming also influenced survivorship in that micro-damming was associated with marginally higher survivorship (47.4 ±2.0% with damming vs. 39.1±1.5% without damming in 2006, and 39.3±1.9% vs. 32.3±1.5% in 2008). Higher planting density only showed a significant positive impact on survivorship in 2008. Neither stem diameter nor clumping significantly affected degree of survival. A key finding in the study has been the non-static nature of P. afra truncheon survivorship, even after being well established (three years since planting). The results from the study will guide the restoration protocols for the restoration of degraded subtropical thickets, where P. afra requires replanting.

The historically poorly conserved subtropical transitional thicket (STT) of the Eastern Cape is overutilised by domestic stock and game in the more xeric areas, and has shown no signs of recovery from this grazing pressure. It has been postulated that no regeneration through seeding occurs. This project was undertaken to determine: 1) how much STT has disappeared between 1950 and present, and what the current conservation status is; and 2) whether regeneration of the xeric succulent thicket is taking place through seeding, and if so, where. The study was conducted at the Andries Vosloo Kudu Reserve near Grahamstown. Approximately one-third less STT was mapped in this study, based on 1981 Landsat images, than was mapped in 1950. Approximately 10 % of all remaining STT is conserved. The order Kaffrarian thicket is poorly conserved. Newly germinated seedlings of a wide range of shrub species occurred under the canopies of a wide range of shrubs which served as nurse plants, throughout a gradient of veld condition. Seedlings of Portulacaria afra, the dominant shrub in xeric succulent thicket, were most common. Similarly all saplings recorded in a survey of saplings were associated with bushclumps. One-third of all saplings have the potential to contribute to the spread of bushclumps. Regeneration of xeric succulent thicket through seeding probably does occur, contrary to current ideas. Ptareoxylon obliquum was the most common sapling, despite mature trees now being scarce following earlier heavier utilisation . P. obliquum was also the nurse plant which supported the highest density of newly germinated seedlings. The possible role of P. obliquum in the functioning of xeric succulent thicket is discussed. The confinement of seedlings and saplings to areas under the canopies of trees and shrubs implies that the xeric succulent thicket will not recover rapidly if allowed to rest. Active management techniques will be necessary if rapid recovery is required. Bare areas between bushclumps may no longer be suitable germination habitats because of high Al concentrations. There was no evidence to support the idea that germination and establishment of shrubs in clear areas is linked to episodic climatic events. Dung middens of recently reintroduced black rhinoceros may however aid in germination of seeds and establishment of seedlings under certain climatic conditions. Recommendations for further studies, based on the findings of this project, are made. Possible management techniques aimed at the rapid recovery of this veld are suggested, and management proposals for the Sam Knott Nature Reserve/Andries Vosloo Kudu Reserve complex are made.

Under the growing demand for marine fish resources, and the apparent and expected impacts of global climate change, there is a need to conduct long-term monitoring (LTM) to ensure effective management of resources and conservation of biodiversity. However LTM programmes often suffer from design deficiencies and fail to achieve their objectives. These deficiencies stem from the fact that insufficient consideration is afforded to the design phase, with programmes selecting methods that are not suitable to address the objectives, or are not cost-efficient, compromising the sustainability of the LTM. To facilitate the establishment of LTM programmes along the southern coast of South Africa, background research needed to be conducted to identify which methods were most appropriate for LTM of reef fish. This study presents a detailed field-based assessment of the suitability and cost-efficiency of monitoring methods for long-term monitoring of reef fish in the Agulhas Ecoregion of South Africa. The approach adopted to identify the method, or suite of methods most suited for LTM, involved (i) the selection of methods considered suitable for LTM, (ii) the individual assessment and optimisation of method performance, and (iii) the comparative assessment of the fish community sampled by the different methods. The most suited method(s) were then identified as those that provide the most comprehensive assessment of the fish community and had the highest cost-efficiency. The research was conducted between January 2008 and 2011 in the Tsitsikamma and Table Mountain National Park (TNP and TMNP, respectively) marine protected areas (MPAs) within the Agulhas Ecoregion. The methods selected included fish traps (FT), controlled angling (CA), underwater visual census (UVC), remote underwater video (RUV), baited RUV (BRUV) and remotely operated vehicles (ROV). The individual assessment and optimisation was conducted with the FT, UVC, RUV and BRUV methods. The assessment of the FT method aimed to identify the optimal soak time, and whether or not the size of the funnel entrance to the trap affected the catch. The results identified that larger funnel entrances caught more fish and soak times of 80 minutes produced the highest catches per unit effort. However the data were highly variable and the method detected few of the species typical of the region. Fish traps were also associated with high levels of mortality of fish post-release. The assessment of UVC strip transect method involved directly comparing the precision of data collected by researchers and volunteers using a novel double-observer technique (paired-transects). The results showed considerable error in both the volunteers and researchers data, however the researchers produced significantly higher precision data, compared to the volunteers. The distinction between researchers and volunteers was not evident in the data for the dominant species of fish. For all observers, the abundance of a species in the sample had a significant influence on its detectability, with locally scarce or rare species poorly detected. UVC was able to sample the majority of species typical of reefs in the region, however it appeared plagued by observer and detectability biases. The assessments of RUV and BRUV were conducted simultaneously which enabled the assessment of the effect of bait on the observed fish community. In addition the optimal deployment time for both methods to maximise species richness and abundance was determined. The results showed that BRUV, and to a lesser degree RUV, were able to effectively survey the reef fish community for the region with a 50 minute and 35 minute deployment time, respectively. Baited remote underwater video was especially good at detecting the invertebrate and generalist carnivores, and cartilaginous species. On the other hand, RUV was more effective at surveying the microinvertebrate carnivores. Remote underwater video was characterised by higher data variability, compared to BRUV, and was ultimately considered a less cost-efficient monitoring method. Comparative methods assessments were conducted during two field experiments with the FT, UVC and BRUV methods in the TMNP MPA, and the FT, CA, UVC, RUV, BRUV and ROV methods compared in the TNP MPA. The objectives of the comparison were to investigate differences in the fish communities observed with the different methods, and to determine the power of the data to detect an annual 10% growth in the fish populations over a period of five years. The results from the method comparison were in turn used to conduct the cost-benefit analysis to determine the efficiency of the different methods at achieving monitoring objectives requiring population data from multiple trophic and functional groups with the community, and from species of fisheries importance. The results indicated that FT, CA and ROV were ineffective at monitoring the reef fish community, although CA appeared to provide valuable data for the dominant fisheries species. Both CA and FT required minimal initial investment however, the variability in the data translated into high annual monitoring costs, as the required sampling effort was great. The ROV required the highest initial investment and was identified as the least cost-efficient method. Underwater visual census was able to adequately survey the bony fish within the community, however it did not detect the cartilaginous species. Underwater visual census required a large initial investment and was not cost-efficient, as a many samples were required to account for the variability in the data. Remote underwater video provided a comprehensive assessment of the reef fish community, however it too was associated with high levels of variability in the data, compared to BRUV, reducing its cost-efficiency. BRUV provided the most comprehensive assessment of the reef fish community and was associated with the highest cost-efficiency to address the community and fisheries species monitoring objectives. During the course of this research stereo-BRUV has gained considerable support as an effective reef fish monitoring method. Although not tested during this research, stereo-BRUV is preferred to BRUV as it provides accurate data on the size of fish. However, the initial investment of stereo-BRUV is over three times that required for the BRUV. Although it is recommended that a baited video technique be used for LTM in the Agulhas Ecoregion, the choice between BRUV and stereo-BRUV will depend on the specific objectives of the programme and the available budget at the implementing agency.

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.

Thesis (MSc)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: The Greater Cederberg Biodiversity Corridor (GCBC) is a large-scale conservation corridor situated in the south-western region of South Africa. Delineation of the GCBC was largely based on by vegetation data. The relevance of the GCBC for the conservation of the reptilian fauna in the area south of 31°S and west of 21°E is assessed in the present study. This entailed determining the GCBC’s coverage of regional reptile diversity patterns and assessing its potential conservation significance during possible climate induced changes in reptile distributions. Reptile species point distribution data from the preliminary (2007) SARCA (South African Reptile Conservation Assessment) database was used. Under-representation of the Tankwa Karoo in the dataset required a field survey of this region. Additionally, the biogeographical influence of the arid Tankwa Karoo Basin on the distribution of reptiles in the south-western districts of South Africa was investigated. Turnover across the Basin is high, species richness is lower than in surrounding mountainous areas and there are no species endemic to the area. The Tankwa Karoo Basin acts as a dispersal barrier for many reptile species occurring in the surrounding more mesic areas. At the same time, the ranges of a number of typical northern, arid adapted species extend southward along the Tankwa Plains. A number of species range extensions in the region are reported. Patterns of endemism, species richness and turnover were plotted from the point distribution data at quarter and eighth degree square resolution. Extensive sampling bias towards reserves and populated areas is apparent from the reptile species richness plots. This pattern is more pronounced for snakes than lizards. Reptile richness is particularly high along the north-south section of the Cape Fold Mountains and also relatively high along the south-western coast, peaking in the Lambert’s Bay area. The majority of the 20 reptile species endemic to the study area are associated with one of two identified centres of endemism: the Greater Cederberg area, or the narrow coastal zone stretching from the Lambert’s Bay area to the Cape Peninsula. An additional third set of endemics comprised of melanistic forms restricted to a number of different refugia, notably, Landroskop, the Cape Peninsula, Sladanha-Langebaan region, Piketberg Mountains and a confined area along the western section of the Cape Fold Mountains. Species richness and endemism patterns co-vary within the study area. Biotic regions were identified through hierarchical clustering of grid cells according to shared species occurrences. A Northern, Southern, Central and Western biotic region was identified. Classification tree methodology (CART) and Canonical Correspondence Analysis (CCA) were used to characterise defined biotic regions in terms of selected environmental variables. Four sets of species assemblages are described on the basis of these biotic regions – two major and two minor ones. Of the major assemblages the Northern assemblage can be described as an arid zone one and the Southern assemblage as a mesic zone one. The minor Central assemblage, comprising mainly rock-dwelling forms, represent evolutionary leftovers as a result of climate change induces cycles of contraction and expansion of arid and mesic faunas. The other minor one, the West Coast assemblage could be considered a sub-assemblage of the Northern one, with particular adaptation to the coastal climate. Environmental characterisation of the biotic regions reveals that these groupings are supported by an environmental signal. The contiguity of four distinct sets of reptiles, each with its own set of environmental requirements, in this relatively small geographic area clearly indicates that the southwestern region of South Africa is biogeographically complex. The GCBC incorporates the largely coinciding centres of endemism and richness along the West Coast and the greater Cederberg area. Although the centre of endemism for melanistic reptile forms, in the Saldanha-Langebaan area, falls just south of the GCBC boundary, the Corridor fulfils the requirements for effective conservation of reptiles in the area to a large degree. The north-south dispersal pathways provided by the Corridor along the Cape Fold Mountains is believed to be adequate to buffer climate change effects, however there is concern about its ability to contribute to the persistence of the assemblage associated with the narrow coastal zone in the west. / AFRIKAANSE OPSOMMING: Die Groter Cederberg Biodiversiteit Korridor (GCBK) is ‘n grootskaalse bewaringskorridor wat in die suid-westelike deel van Suid-Afrika geleë is. Die grense van GCBK is gebasseer op plantegroei data. In die huidige studie word die betekenis van die GCBK vir die bewaring van die reptiel fauna in die gebied suid van 31°S en wes van 21°O assesseer. Die mate waartoe die GCBK die patrone van reptieldiversiteit in die streek inkorporeer, asook die korridor se potensiaal om voorsiening te maak vir reptiel verspreidingsgebiede wat moontlik as gevolg van potensiële omgewingsverandering kan verskuif. Die beskikbare puntverspreidingsdata van die voorlopige (2007) SARCA (South African Reptile Conservation Assessment) databasis is gebruik. Swak verteenwoordiging van die Tankwa Karoo in die datastel het ‘n veldopname van die gebied genoodsaak. Verder is die biogeografiese invloed van die ariede Tankwa Karoo Kom op die verspreidingspatrone van reptiele in die suid-westelike deel van Suid-Afrika ook ondersoek. Die spesie omset van beide Noord na Suid en Wes na Oos oor die Tankwa is hoog, die spesierykheid is aansienlik laer as in die omringende bergagtige gebiede en daar is geen spesies wat endemies is tot die Tankwa Karoo nie. Die Tankwa Karoo Kom dien as ‘n barieêre teen spreiding vir sommige reptielspesies wat in die omringende gematigde gebiede voorkom. Terselfdertyd reik die verspreidings van ‘n aantal tipiese droogte aangepasde spesies vanuit die noorde suidwaarts langs die Tankwa Vlaktes. Nuwe verspredingsrekords wat ‘n paar spesies se gebiede uitbrei word ook raporteer. Die puntverspreidingsdata is geruik om die patrone van endemisme, spesierykheid en omset op kwart- en agtstegraad resolusie te plot. Spesierykheid kaarte toon ‘n duidelike neiging tot deegliker opnames in reservate en bewoonde gebiede. Hierdie patroon is meer opmerklik vir slange as akkedisse. Reptielrykheid is besonders hoog langs die noord-suid as van die Kaapse Plooiberge en ook relatief hoog langs die suid-wes kus met ‘n maksimum in die Lambertsbaai omgewing. Die meerderheid van die 20 reptielspesies wat endemies is aan die studie area is met een van twee geïdentifiseerde sentrums van endemisme geassosieer: die Groter Cederberg area óf die nou kussone wat vanaf Lambertsbaai tot Kaappunt strek. ‘n Derde stel endemiese spesies wat uit melanistiese vorme bestaan, is beperk tot ‘n aantal refugia, naamlik, Landroskop, Kaappunt, Saldanha- Langebaan omgewing, Piketberg berge en ‘n beperkte area langs die westelike dele van die Kaapse Plooiberge. Spesierykheid en endemisme patrone stem grootliks ooreen binne die studie area. Roosterselle is op grond van gedeelde spesiesamestellings met behulp van ‘n hieragiese groeperingsmetode (Incremental Sum of Squares) gegroepeer. Vier bio-areas, nl. ‘n Noordelike-, Suidelike-, Sentrale en Westelike bio-area is identifiseer. Klassifikasieboom metodologie (Classification and Regression Trees, CART) asook Kanoniese Annalises (Cannonical Correspondence Annalysis, CCA) is gebruik om hierdie geografiese areas in terme van ‘n aantal omgewingsveranderlikes te karakteriseer. Vier spesieversamelings, twee groter en twee kleiner versamelings, is in ooreenstemming met hierdie vier areas geïdentifiseer. Die Noordelike en Suidelike spesieversamelings is die groteres en kan beskryf word as die faunas van onderskeidelik ‘n ariede en gematigde sone. Die kleiner Sentrale versameling bestaan hoofsaaklik uit rots-lewende spesies en mag die evolusionêre oorblyfsels verteenwoordig van ariede en gematigde faunas waarvan die verspreidings herhaaldelik as gevolg van klimaatsveranderingsiklusse uitgebrei en gekrimp het. Die Weskus versameling is ook ‘n kleiner een en kan as ‘n sub-versameling van die Noordelike een beskou word, maar spesifiek tot die kus klimaat aangepas. Die klassifikasie van hierdie bio-areas word ondersteun deur die analiese van die omgewingsveranderlikes. Die feit dat vier kenmerkende versamelings reptiele, elk met sy besondere omgewingsvereistes, in hierdie relatief klein geografiese area ontmoet, dui daarop dat die suid-westelike deel van Suid-Afrika biogeografies kompleks is. Die GCBK inkorporeer die grootliks ooreenstemmende sentrums van endemisme en rykheid wat langs die Weskus en in die groter Cederberg area voorkom. Alhoewel die sentrum van melanistiese endemiese spesies, in die Saldanha-Langebaan omgewing, net buite die grense van die Korridor val, voldoen die GCBK grootliks aan die vereistes vir die effektiewe bewaring van reptiele in die gebied. Die voorsiening van noord-suid verspreidingsweë langs die Kaapse Plooiberge binne die Korridor word beskou as voldoende om die gevolge van klimaatsverandering te buffer. Daarinteen is daar kommer oor die vermoeë van die GCKB om ‘n doeltreffende bydrae te maak tot die voortbestaan van die spesieversameling wat met die nou kussone langs die Weskus geassosieer is.

Thesis (MBA)--University of Stellenbosch, 2011. / The government has stated its intentions to increase the usage of solar water heating (SWH) through its National Solar Water Heater Programme (NSWHP). As described in the report, increased adoption of SWH would have a number of benefits for South Africa. Firstly, replacement of electric geysers by SWHs would contribute to the meeting of energy efficiency targets through the reduction of energy consumption. Secondly, the widespread adoption of SWHs would help SA to meet its renewable energy targets. Thirdly, it would result in growth in the SWH industry, including the manufacturing, installation and related sectors, thereby contributing to an increase in 'green' jobs. It would have the socio-economic benefit of energy security for South Africans. The research report looks at the factors influencing the SWH industry's future growth from the point of view of the suppliers. It considers the interplay between consumers (market demand), government (public policy measures) and suppliers (businesses providing services related to SWH) to determine how government can support industry, how suppliers can grow their business and industry and how government and industry can work together to create the conditions for sustained market demand. As is discussed in the literature review, there are certain barriers to the adoption of SWH technology. As such, government intervention is needed to help overcome these barriers. The literature review recounts the available policy tools and considers how these have been applied in other countries to stimulate demand for SWHs and to support the local industry. The research report takes the form of a survey of SWH suppliers with the following aims: - To describe the industry in terms of its age, maturity and ability to scale up; - To determine the major barriers to the industry's growth; - To specify the appropriate public policy tools to overcome these obstacles to growth; - To establish how confident the industry is in the NSWHP and government efforts to promote the industry; - To provide a list of key success factors that are required for the industry's long-term, sustainable development. The report concludes that there are three criteria that would help the industry to become sustainable: market demand certainty, investment confidence and positive competition. Certainty of future market demand would build confidence in the industry for investors. In turn, increased investment would benefit the forces of positive competition.

Thesis (PhD)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The aims of this study were to investigate genetic issues pertaining to the conservation of the Knysna seahorse, Hippocampus capensis, and to determine the phylogenetic placement of this endangered estuarine species among marine seahorses. This was accomplished by focusing on three aspects of the taxonomy: the interspecific level; the inter-population level; and the intra-population level. To determine which species are closely related to H. capensis, and how the evolutionary history of this lineage relates to that of other seahorses, sequence data derived from four gene fragments (the nuclear RPI and Aldolase and the mitochondrial 16S rRNA and cytochrome b genes) were used to determine the phylogenetic relationships among 30 species belonging to the genus Hippocampus. There were marked differences in the rate of evolution among these gene fragments, with Aldolase evolving the slowest and the mtDNA cytochrome b gene the fastest. Among individual partitions, the RPI gene recovered the highest number of nodes supported by >70% bootstrap values from parsimony analysis, and >95% posterior probabilities from Bayesian inference. The combined analysis based on 2317 nucleotides resulted in the most robust phylogeny. A distinct phylogenetic split was identified between the pygmy seahorse, H. bargibanti, and a clade including all other species. Three species from the western Pacific Ocean included in this study, namely H. bargibanti, H. breviceps, and H. abdominalis, occupy basal positions in the phylogeny. This and the high species richness in the region suggest that the genus probably originated in this region. There is also fairly strong molecular support for the remaining species being subdivided into three main evolutionary lineages: two West Pacific clades and a clade of species present in both the Indo-Pacific and the Atlantic Ocean, which includes H. capensis. The phylogeny obtained herein suggests that seahorses belonging to the latter clade colonised the Atlantic Ocean at least twice, once before the closure of the Tethyan Seaway, and once afterwards. Phylogenies reconstructed using mitochondrial DNA gene fragments (l6S rRNA, cytochrome band 382 bp of the rapidly evolving control region) indicate that H. capensis is closely related to an Indian Ocean lineage of H. kuda and a Red Sea lineage of H. fuscus. Other lineages closely associated with these taxa include H. kuda from the West Pacific, the East Atlantic species H. algiricus, the West Atlantic species H reidi, the East Pacific species H ingens, and the Hawaiian species H fisheri. No control region alleles were shared among H capensis and any of the marine seahorses, suggesting that the Knysna seahorse is phylogenetically distinct. The evolutionary history of H capensis, and the extent of gene flow between its three known populations, were investigated using control region sequences from 138 specimens. Most samples were obtained by taking fin clips; this method was studied on captive seahorses and no negative effects were found. Similarly high levels of genetic diversity were found in two of the wild populations (Knysna and Keurbooms Estuaries), whereas diversity in the third population (Swartvlei Estuary) was lower. Although most haplotypes are shared among at least two populations, based on the haplotype frequency distributions the three assemblages constitute distinct management units. The extant population structure of H capensis suggests that the Knysna seahorse originated in the large Knysna Estuary. The presence of seahorses in the two smaller estuaries is either the result of a vicariance event at the beginning of the present interglacial period, or colonisation of the estuaries via the sea, or a combination of the two. Population genetic parameters of the Knysna population and those of two populations of closely related marine seahorses (H kuda from the Philippines and H fuscus from the Red Sea) were similar, suggesting that the Knysna population is not genetically impoverished, despite its comparatively small area of occupancy. / DEUTSCHE ZUSAMMENFASSUNG: Die hier prasentierte wissenschaftliche Studie beschaftigte sich mit genetischen Themen relevant flïr den Artenschutz des Knysna Seepferds, Hippocampus capensis, und den phylogenetischen Beziehungen dieser ausschliesslich in Estuaren (Flussmtindungen) vorkommenden gefahrdeten Art mit den im Meer lebenden Seepferden. Die folgenden taxonomischen Einheiten wurden verglichen: Arten, Populationen und Sub-Populationen. Urn festzustellen, welche Arten nah mit H. capensis verwand sind, und wie die Evolution dieser Gruppe sich von der anderer Seepferdgruppen unterscheidet, wurden genetische Sequenzen von vier Genen (den nuklearen RPI und Aldolase und den mitochondrischen 16S rRNA und Cytochrom b Genen) von 30 Seepferdarten verwendet und phylogenetische Beziehungen rekonstruiert. Betrachtliche Unterschiede wurden festgestellt hinsichtlich der Geschwindigkeit in der Mutationen stattgefunden haben: Aldolase mutierte am langsamsten und Cytochrom b am schnellsten. Eine auf RPI Sequenzen basierende Phylogenie hatte die hëchste Anzahl von Gabelungspunkten, die sowohl von parsimonischen Analysen, als auch von bayesischer Inferenz untersttitzt wurden. Die robusteste Phylogenie wurde jedoch gefunden, wenn Sequenzen von allen vier Genen kombiniert wurden (im ganzen 2317 Nukleotide). Eine betrëchtliche genetische Distanz wurde zwischen dem Pygmaen-Seepferd, H. bargibanti, und einer Gruppe, die aus allen anderen Arten bestand, gefunden. Drei Arten vom westlichen Pazifik, namlich H. bargibanti, H. breviceps und H. abdominalis, hatten basale Positionen in der Phylogenie. Das, und der Artenreichtum dieser Region, sind Anzeichen daflïr, dass Seepferde mëglicherweise ursprtinglich aus dem westlichen Pazifik stammen. Es wurde weiterhin gefunden, dass alle tibrigen Seepferdarten in drei Hauptgruppen unterteilt werden kannen: die Verbreitungsgebiete zweier dieser Gruppen beschranken sich hauptsachlich auf den westlichen Pazifik, aber die dritte Gruppe kommt sowohl im Indo-Pazifik, also auch im Atlantik vor (H. capensis ist mit dieser letzteren Gruppe assoziiert). Es gibt gute Anzeichen dafllr, dass die Seepferde der letztgenannten Gruppe den Atlantik mindestens zweimal kolonisiert haben, einmal vor der Schliessung der tethyschen Seeverbindung, und einmal danach. Phylogenien, die ausschliesslich mit mitochondrischen Genen rekonstruiert wurden (16S rRNA, Cytochrom b und 382 Nukleotide der schnell-mutierenden Kontollregion), zeigen, dass H capensis sehr nah verwandt mit H kuda aus dem Indischen Ozean und H fuscus aus dem Roten Meer ist. Andere nah verwandte Arten sind H kuda from westlichen Pazifik, H algiricus vom ëstlichen Atlantik, H reidi vom westlichen Atlantik, Hingens vom ëstlichen Pazifik, sowie die in Hawaii vorkommende Art H fisheri. Keine der Kontrollregionallele, die in H capensis gefunden wurden, kamen in anderen Arten vor. Dies zeigt, dass das Knysna Seepferd eine eigenstandige Art ist, und Paarungen mit anderen Arten nicht vorkommen. Die Evolutionsgeschichte von H capensis, und das Ausmass von genetischem Austausch zwischen den drei Populationen dieser Art, wurden untersucht, indem Kontrollregionsequenzen von 138 Individuen analysiert wurden. Die meisten Proben stammten von Flossenschnitten; diese Methode wurde zuvor an in Gefangenschaft lebenden Seepferden ausprobiert, und es wurden keine negativen Folgeerscheinungen beobachtet. Genetische Diversitat war ungefahr gleich hoch in zwei der Populationen (Knysna und Keurbooms Estuare), aber eine deutlich niedrigere Diversitat wurde in der dritten Population gefunden (Swartvlei Estuar). Obwohl die meisten Allele in mindestens zwei Populationen gefunden wurden, sind die drei Populationen unterschiedliche genetische Einheiten, eine Schlussfolgerung, die hauptsachlich auf Unterschiede in der relativen Haufigkeit der Allele beruht. Die Populationsstruktur von H capensis deutet darauf hin, dass diese Art ihren Ursprung im Knysna Estuar hat. Die Prasenz von Seepferden in den beiden anderen Estuaren ist entweder das Resuitat von Vikarianz (eine Spaltung der urspri.inglichen Population) zu Beginn der jetzigen Interglazialzeit, oder Kolonisierung der Estuare durchs Meer, oder eine Kombination beider Szenarios. Populationsgenetische Parameter der Knysna Population und die zweier Populationen von nah verwandten Arten (H kuda aus den Philippinen und H fuscus aus dem Roten Meer) zeigten keine grossen Unterschiede. Dies deutet darauf hin, dass das Knysna Seepferd trotz seines vergleichbar kleinen Verbreitungsgebietes nicht unter geringer genetischer Diversitat leidet. / AFRIKAANSE OPSOMMING Die doelwitte van hierdie studie was om die Knysna seeperdjie, Hippocampus capensis, te ondersoek relatief tot die spesie se bewaring asook om die filogenetiese posisie van hierdie bedreigte estuariene spesie binne mariene seeperdjies te bepaal. Drie aspekte van die taksonomie word ondersoek: interspesie verwantskappe, interbevolking verwantskappe en intra-bevolking verwantskappe. Om te bepaal watter spesies na verwant is aan H capensis, asook om die evolusionêre geskiedenis van hierdie groep met die van ander groepe te vergelyk, word nukleotieddata van vier ONS fragmente (die nukleêre RPI intron en Aldolase, en die mitochondriale 16S rRNA en sitokroom b fragmente) van 30 spesies van die genus Hippocampus gebruik. Aansienlike verskille in die tempo van evolusionêre verandering tussen hierdie ONS fragmente word gevind: Aldolase was die stadigste en die mitochondriale sitokroom b die vinnigste. Die RPI intron het die meeste knoesteringe gehad wat ondersteun word deur hoë stewelvasgordnommers (>70%) van parsimoniese analises en hoë agterwaarskynlikheide (>95%) van Bayesiese gevolgtrekkinge. Die kombineerde analise wat 2317 nukleotiede ingesluit het, het die beste filogenie geproduseer. 'n Besliste filogenetise verdeling was gevind tussen die pigmee seeperdjie, H bargibanti, en 'n groep wat al die ander spesies ingesluit het. Drie spesies van die westelike Stille Oseaan wat in hierdie studie ingesluit is, H bargibanti, H breviceps en H abdominalis, neem primitiewe posisies in die filogenie in. Dit, en die hoë spesiesrykdom in daardie gebied dui aan dat dit moontlik is dat die genus in die westelike Stille Oseaan ontstaan het. Daar is ook taamlike goeie molekulêre ondersteuning dat al die ander spesies in drie evolusionêre hoofgroepe verdeel kan word: twee groepe wat hoofsaaklik in die westelike Stille Oseaan voorkom, en 'n groep van spesies wat in die Stille Oseaan, die Indiese Oseaan en in die Atlantiese Oseaan voorkom, wat H capensis insluit. Die filogenie wat hier gevind is dui aan dat seeperdjies van hierdie laas genoemde groep die Atlantiese Oseaan minste twee keer gekoloniseer het, een keer voor die sluiting van die Tetiese Seepad, en een keer daarna. Filogenies wat met mitochondriale ONS fragmente gerekonstrueer is (16S rRNA, sitokroom b en 382 nukleotide van die vinnig evolveerende kontrolestreek) dui aan dat H capensis na verwant is aan 'n groep van H kuda wat in die Indiese Oseaan voorkom en H fuscus van die Rooi See. Ander groepe wat na verwant is aan hierdie takson is H kuda van die westelike Stille Oseaan, H algiricus van die Oos Atlantiese Oseaan, H reidi van die Wes Atlantiese Oseaan, en die Hawaiise spesie H fisheri. Geen kontrolestreek allele was gedeel tussen H capensis en enige mariene seeperdj ie spesies; dit dui aan dat die Knysna seeperdjie filogeneties verskillend is. Die evolusionêre geskiedenis van H capensis, en die omvang van die genetiese interaksies tussen sy drie bekende bevolkings, word ondersoek met kontrolestreek nukleotieddata van 138 monsters. Die meeste van hierdie monsters was verkry deur vinknipsels; hierdie metode was getoets op seeperdjies in gevangenskap en geen negatiewe gevolge was gevind nie. Genetiese diversiteit was omtrent dieselfde in twee van die natuurlike bevolkings (Knysna en Keurbooms Estuariums), maar diversiteit in die derde bevolking (Swartvlei Estuarium) was laër. Alhoewel die meeste allele gedeel was tussen ten minste twee bevolkings, dui die verspreiding van allelfrekwensies aan dat die drie bevolkings aparte bestuurseenhede is. Die ekstante bevolkingsstruktuur van H capensis dui aan dat die Knysna seeperdjie in die groot Knysna Estuarium ontstaan het. Die teenwordigheid van seeperdjies in die twee kleiner estuariums is óf die resultaat van 'n vikariansie voorval aan die begin van hierdie interglasiale tydperk, óf kolonisasie van die estuariums deur die see, óf 'n kombinasie van albei. Bevolkingsgenetiese parameters van die Knysna bevolking en van twee bevolkings van na verwante seeperdjie spesies (H kuda van die Filippyne en H fuscus van die Rooi See) was soortgelyk, wat aandui dat die Knysna bevolking nie geneties verarm is nie, alhoewel dit 'n betreklik kleiner streek bewoon.

Dissertation (PhD)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Historically, isopods of the suborder Phreatoicidea were thought to be represented in southern Africa by four species belonging to the endemic genus Mesamphisopus. This taxonomy was based on poor collections and the extent of variation among and within populations were poorly understood. In the present study, intensive sampling was undertaken to determine the diversity, distribution and biogeography of phreatoicidean isopods within South Africa. Analyses of allozyme data and mitochondrial DNA sequences (from the 12S rRNA and protein-coding COI genes) were used to examine differentiation among populations, extricate species boundaries (in combination with morphometric and morphological data) and to elucidate the evolutionary relationships among taxa. Additionally, conservation units were identified among the sampled populations and conservation threats highlighted. First, genetic and morphometric differentiation was examined among populations identified morphologically as M. capensis. Collection localities spanned two mountainous regions in the Western Cape and these were separated by a coastal plain remnant. Five morphometrically and genetically distinct species were identified. These taxa are also geographically partitioned in two regions, which were regarded as Evolutionarily Significant Units. Differentiation among populations of the two regions, and similar patterns in other taxa, was attributed to Cenozoic sea-level fluctuations. Second, populations, variably assigned to M. abbreviatus or M. depressus, were examined to determine whether they were conspecific. A large geographic area was sampled to account for intraspecific differentiation. Limited morphometric discrepancies were observed, with individual populations being either similar to the M. abbreviatus or the M. depressus syntypes. Genetic support for the recognition of a cryptic species complex among the sampled populations was equivocal. Substantial genetic differentiation and a lack of gene flow were observed among all populations. Clear patterns of isolation by distance were not detected, and genetic structure appeared to be unrelated to geography or drainage systems. The mosaic pattern of relatedness among populations was best explained by stochastic demographic processes, such as extinction-recolonization events or population bottlenecks.Thirdly, detailed taxonomic descriptions and illustrations of six new species, identified genetically and morphometrically among the populations included in the above analyses, were provided. These species were largely distinguished from each other, and the four original species, using a combination of setation, mouthpart, pleopod and uropod features. Lastly, phylogenetic relationships among all ten recognized Mesamphisopus species, and an additional unresolved group of populations, were examined. MtDNA data partitions and a recoded allele frequency matrix were analysed independently and in combination. Topologies indicated unrecognized species-diversity within an unresolved group of populations. Evolutionary relationships, the identification of six biogeographic centres, and the dating of divergences using a relaxed Bayesian clock suggested that differentiation and speciation within Mesamphisopus was largely allopatric or vicariant and driven by Mesozoic sea-level and climate change. Chance long distance dispersal events would, in turn, explain spurious phylogenetic relationships and distributions. This study contributes significantly to the understanding of the diversity and the conservation of the little-studied southern African freshwater invertebrates. Moreover, this study is the first to investigate genetic and morphometric differentiation, and phylogenetic relationships, below the generic level within the Phreatoicidea; thus establishing a methodological and theoretical framework for species delineation and the accurate determination of biodiversity within individual phreatoicidean genera. / AFRIKAANSE OPSOMMING: Isopoda van die suborder Phreatoicidea was histories in suidelike Afrika verteenwoordig deur vier spesies wat almal aan die endemiese genus Mesamphisopus behoort. Hierdie taksonomie is op ’n beperkte hoeveelheid versamelings gebaseer en die omvang van variasie tussen (en binne) bevolkings was swak verstaan. In die huidige studie is ekstensiewe versameling onderneem om die verspreiding, diversiteit asook biogeografie van dié Isopoda in Suid Afrika te bepaal. Analises van allosiem data en mitokondriale DNS volgorderbepalings (van die 12S rRNS en die proteïenkoderende COI geen) was gebruik om differensiasie tussen bevolkings te ondersoek, om (in kombinasie met morfometriese en morfologiese data) spesiesgrense te bepaal asook om die evolusionêre-verwantskappe tussen taksa te definieer. Benewens word bewaringseenhede binne die studie-bevolkings geïndentifiseer en moontlike bedreigings uitgelig. Eerstens is genetiese en morfometriese differensiasie tussen bevolkings, wat as M. capensis geïdentifiseer is, ondersoek. Versamelingslokaliteite was versprei oor twee bergagtige streke in die Weskaap wat geskei word deur ’n voormalige kusvlakte. Vyf morfometries- en geneties-afsonderlike spesies is geïdentifiseer. Dié taksa was geografies geskei tot die twee streke, wat elk as ’n Evolusionêre Beduidende Eenheid (ESU) gesien kan word. Differensiasie tussen populasies van die twee streke en vergelykbare patrone binne ander taksa word aan Cenosoïese seevlak veranderings toegeskryf. Tweedens is bevolkings wat as M. abbreviatus óf as M. depressus geïdentifiseer kan word ondersoek om te bepaal of hulle konspesifiek is. Bevolkings is oor ’n groot geografiese gebied versamel om intraspesifieke variasie in aanmerking te neem. Beperkte morfometriese verskille is waargeneem – enkel bevolkings was morfometries identies aan of die M. abbreviatus of die M. depressus sintipes. Genetiese getuienis vir die herkenning van ’n kriptiese spesieskompleks was dubbelsinnig. Bevolkings is gekenmerk deur merkbare genetiese differensiasie en die afwesigheid van geenvloei. Duidelike bewys van isolasie-metafstand was nie waargeneem nie en genetiese struktuur was nie verwant aan geografiese ligging of riviersisteme nie. Die mosaïese patroon van verwantskappe is moontlik teweeg gebring deur stogastiese demografiese prosesse soos uitsterwing en hervestiging of deur afnames in bevolkingsgrootte.Derdens is omvattende taksnomiese beskrywings en illustrasies van ses nuwe spesies wat deur bogenoemde analises geneties en morfometries uitgelig was, verskaf. Dié spesies is van mekaar, asook die ander vier spesies onderskeibaar deur ’n kombinasie van setasie-, monddeel-, pleiopoot- en uropooteienskappe. Laastens is die filogenetiese verwantskappe tussen al tien herkende Mesamphisopus-spesies en ’n groep bevolkings waarvan verhoudings onseker was, ondersoek. MtDNS datastelle en ’n hergekodeerde alleelfrekwensie matriks is afsonderlike en in kombinasie geanaliseer. Topologië het onherkende spesies-vlak diversiteit binne die bogenoemde groep bevolkings aangedui. Evolusionêre verwantskappe, die herkenning van ses biogeografiese gebiede, en die bepaling van tye van divergensie (d.m.v. ’n ontspanne Bayesiaanse molekulêre klok) het aangetoon dat spesiasie binne Mesamphisopus grootliks allopatries was en deur Mesosoïese seevlak- en klimaatsveranderings teweeg gebring is. Toevallige lang-aftstand verspreiding kon dan eienaardige filogenetiese verhoudings en verspreidings verklaar. Dié studie lewer ’n wesenlike bydrae tot die kennis van die diversiteit en tot die bewaring van die onbestudeerde Suid Afrikaanse varswater ongewerweldes. Daarenbowe, is hierdie studie die eerste om genetiese en morfometriese differensiasie benede die genusvlak binne die Phreatoicidea te ondersoek; sodoende word die metodologiese en teoretiese raamwerk vir die herkenning van spesies en die akkurate beskrywing van diversiteit binne afsonderlike genera van die Phreatoicidea geskep.

A fading legacy Through the intensive investigation of the rhino trade, the thesis proposes the development of a biodiversity center to serve as a research, education, training and enforcement facility which will support a legalized rhino horn trade. The relationship between architecture and nature. In so doing, it questions whether architecture can effectively facilitate the conservation of our spectacular wildlife through and ecological approach to brief, site and context. The thesis promotes and architecture that is respectful of its natural surroundings. An architecture that provides occupants with facilities that are conducive to the conservation of endangered species.

Thesis (M.A. (Sociology)) -- University of Limpopo, 2000 / Please refer to the document