A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2014. / Landscapes are highly organised, with recurring patterns of co-varying and interacting biotic and abiotic ecosystem components. Although there is a rising demand for landscape classifications and maps that describe these patterns, emerging conceptualisations of ecosystems as complex, open and inherently uncertain question the existence of geographically definable ecological regions. It is now well recognised that perceptions of ecological patterns are highly subjective, changing with the scale of observation and the particular combination of environmental attributes that are emphasised. Hence many different valid descriptions (and hence maps) of the same ecosystem are possible, each relating to different perspectives and issues. This thesis aims to develop a conceptualization of the biophysical interactions that fashion the character and behaviour of water-dependent ecosystems in savanna landscapes that can be used to underpin land classifications and maps for transdisciplinary enquiry and the management and allocation of natural resources. Recent analytical approaches in geomorphology, hydrology, soil science and biogeography are synthesised in a heuristic landscape hierarchy that frames hillslopes within the context of a stream network that varies between different geological and climatic settings. Savanna landscapes offer excellent opportunities to develop this new approach, since many hydrological, geomorphic and biotic processes are tightly coupled around the limited availability of water. Thus many biotic and abiotic variables are spatially clustered, forming a biophysical template that constrains the character and behaviour of a wide range of organisms and processes. Maps of these clusters can therefore provide a platform for integrating a similarly wide range of scientific and managerial perspectives. The credibility and relevance of the conceptualisation is assessed through its application to a land classification in Kruger National Park (KNP), South Africa. The approach is iterative and reflective, endeavouring to reconcile the impossibility of using traditional reductionist approaches to describe complex systems with the need for reductionist generalisations to describe and analyse complex systems. Assumptions and decisions form a narrative that expressly acknowledges the inclusion of normative values and subjective judgements in conceptualisations of complex systems. Implementation is based around the use of generalised archetypes to navigate between general principles and particular instances and also between conceptualisations and their representation in a map. Rather than using standardised, pre-determined scales and attributes, archetype development is based on the extensive research that exists for KNP, together with observation and analyses that give the landscape a ‘voice’, using concepts such as hillslope catenas and topographic grain. Analytical lenses are reframed to reveal differences as well as similarities, recognising that not all instances of a class are equally similar to the class archetype, so that some locations may conform more than others to the anticipated class character and behaviour. At regional scales, physiographic zones are characterised by particular geology, patterns of landscape dissection and catchments that contain certain repeating toposequences of catenal elements. Differences in topographic grain have substantial implications for the construction of ecological maps, since the optimum scales of observation for the same level of the landscape hierarchy differ between landscapes. The associated differences in catchment size, hillslope length and stream density also have profound impacts on the nature and scale of many ecological processes, such that differentiation between physiographic zones is vital for good science, modelling and management. Two study sites were mapped at catchment and hillslope scales, serving to contrast landscape structures in the finely dissected granites and the coarsely dissected basalts. At both catchment and hillslope scales, the basalt site conformed well to the a priori archetype that described a vegetation toposequence. However, only about half the area of the granite study corresponded to the archetype. Many of these mismatches did not show any difference in vegetation between midslopes and crests, suggesting they lack the contrasting clay/sandy soils that are typical of catenas in this area. It was therefore concluded that these subcatchments are likely to be generated and sustained by a different suite of processes to those described by the archetype and may therefore warrant the development of new archetypes. These findings illustrate how the explicit mapping of catenal elements allows the variability within an area to be assessed, identifying anomalous areas and hillslopes that are likely to behave differently to the hillslopes that conform more precisely to archetypal conceptual models. Understanding the nature and extent of such variations will improve the performance of broad-scale extrapolations and models based on the behaviour of idealised archetypes. Ultimately, end users will determine whether or not the conceptualisation of savanna landscapes developed in this thesis is capable of rising to the challenges posed by the complexity and heterogeneity of ecological systems in KNP (and elsewhere). Initial indications are positive, given the early uptake of the approach both by the South African Water Research Commission and South African National Parks (SANParks).

Thesis (MA (History))--University of Stellenbosch, 2007. / A cultural landscape is a geographical area that includes the associations of cultural and natural resources of historic events, actions, person or groups of people. A cultural landscape gives one a sense of belonging. It explains relationships between man and land over time; it is part of a national heritage and part of every person’s life. The value of cultural landscapes is vested in the fact that they include a variety of diverse environments. The motive of selecting this subject for search is the prominent disregard of existing culture in certain cultural landscapes and creation of new artificial cultural landscapes with profit exclusively as its main goal. One of the aims of the study is to look at the threats of cultural landscapes. The concept cultural landscapes is extensively explained in context of its advantages and disadvantages. Sustainable tourism development is closely connected to sustainable development of heritage sites. Local government should therefore develop a cultural tourism policy in collaboration with private stakeholders and local residents as a matter of priority. The focus is on the balance between values of cultural heritage and potential economic opportunities for local communities. The procedure of the declaration of World Heritages sites is also dealt with. The purpose of the case studies is to use local examples in order to reflect the situation in the Western Cape with respect to cultural landscapes. Two cases of cultural landscapes were researched, namely the Karoo Heritage Landscape’s upgrading of the golf course in Oudtshoorn with a proposed new housing development, and a proposed development and extension at the Boschendal Farmers Estate in the Franschhoek district. Guidelines and examples for managing the models for conservation of cultural landscapes are given, which include natural and cultural resources as well as the concerns of the local communities. The need for a global strategy is strongly emphasized. UNESCO’S World Heritage List of Cultural Landscapes is attached as an appendix.

The subtropical thicket biome in the Eastern Cape Province of South Africa has been heavily degraded and transformed due overutilization during the last century. The highly degraded and transformed areas exhibit a significant loss of above ground carbon stocks (AGC) and loss of SOC content. Information about land use /cover change and fragmentation dynamics is a prerequisite for measuring carbon stock changes. The main aim of this study is to assess the trends of land use/cover change, fragmentation dynamics, model the temporal changes of AGC stocks in the Great Fish River Nature Reserve and its environs from 1972 to 2010, quantify and map the spatial distribution of SOC concentrations in the partial subtropical thicket cover in the Great Fish River Nature Reserve and environs (communal rangelands). Multi-temporal analyses based on 1972 Landsat MSS, 1982 and 1992 Landsat TM, 2002 Landsat ETM and 2010 SPOT 5 High Resolution images were used for land use/cover change detection and fragmentation analysis. Object oriented post-classification comparison was applied for land use/cover change detection analysis. Fragmentation dynamics analysis was carried out by computing and analyzing landscape metrics in land use/cover classes. Landscape fragmentation analyses revealed that thicket vegetation has increasingly become fragmented, characterized by smaller less linked patches of intact thicket cover. Landscape metrics for intact thicket and degraded thicket classes reflected fragmentation, as illustrated by the increase in the Number of Patches (NP), Patch Density (PD), Landscape Shape Index (LSI), and a decrease in Mean Patch Size (MPS). The use of remote sensing techniques and landscape metrics was vital for the understanding of the dynamics of land use/cover change and fragmentation. Baseline land use/cover maps produced for 1972, 1982, 1992 2002 and 2010 and fragmentation analyses were then used for analyzing carbon stock changes in the study area. To model the temporal changes of AGC stocks in the Great Fish River Nature Reserve and its environs from 1972 to 2010, a method based on the integration of RS and GIS was employed for the estimation of AGC stocks in a time series. A non-linear regression model was developed using NDVI values generated from SPOT 5 HRG satellite imagery of 2010 as the independent variable and AGC stock estimates from field plots as the dependent variable. The regression model was used to estimate AGC stocks for the entire study area on the 2010 SPOT 5 HRG and also extrapolated to the 1972 Landsat MSS, 1982 and 1992 Landsat TM, and 2002 Landsat ETM. The AGC stocks for the period 1972 -1982, 1982-1992, 1992-200) and 2002-2010 were compared by means of change detection analysis. The comparison of AGC stocks was carried out at subtropical thicket class level. The results showed a decline of AGC stocks in all the classes from 1972 to 2010. Degraded and transformed thicket classes had the highest AGC stock losses. The decline of AGC stocks was attributed to thicket transformation and degradation which were caused by anthropogenic activities. To map and quantify SOC concentration in partial (fractional) thicket vegetation cover, the spectral reflectance of both thicket vegetation and bare-soils was measured in situ. Soil samples were collected from the sampling sites and transported to the laboratory for spectral reflectance and SOC measurements. Thicket vegetation and bare soil reflectance were measured using spectroscopy both in situ and under laboratory conditions. Their respective endmembers were extracted from ASTER imagery using the Pixel Purity Index (PPI). The endmembers were validated with in situ and laboratory thicket and bare-soil reflectance signatures. The spectral unmixing technique was applied to ASTER imagery to discriminate pure pixels of thicket vegetation and bare-soils; a residual spectral image was produced. The Residual Spectral Unmixing (RSU) procedure was applied to the residual spectral image to produce an RSU soil spectrum image. Partial Least Squares Regression (PSLR) model was developed using spectral signatures of a residual soil spectrum image as the independent variable and SOC concentration measured from soil samples as the dependent variable. The PSLR prediction model was used to predict SOC concentration on the RSU soil spectral image. The predicted SOC concentration was then validated with SOC concentration measured from the field plots. A Strong correlation (R2 = 0.82) was obtained between the predicted SOC concentration and the SOC concentration measured from field samples. The PSLR was then used to generate a map of SOC concentration for the Great Fish River Nature Reserve and its environs. Areas with very low SOC concentrations were found in the degraded communal villages, as opposed to the higher SOC values in the protected area. The results confirmed that RS techniques are key to estimating and mapping the spatial distribution of SOC concentration in partial subtropical thicket vegetation. Partial thicket vegetation has a huge influence on the soil spectra; it can influence the prediction of SOC concentration. The use of the RSU approach eliminates partial thicket vegetation cover from bare soil spectra. The residual soil spectrum image contains enough information for the mapping of SOC concentration. The technique has the potential to augment the applicability of airborne imaging spectroscopy for soil studies in the sub-tropical thicket biome and similar environments.

Thesis (MSc)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: The conservation of biodiversity is becoming increasingly challenging as habitats are disturbed, fragmented or destroyed. Although nature reserves now cover more than 10 % of the earths’ surface it has become clear that more will have to be done to ensure the long-term survival of species. Therefore, focus is increasingly shifting towards conserving biodiversity in natural and semi-natural remnants in human-influenced areas. This study aimed to determine the contribution of remnants in human-influenced areas to the conservation of biodiversity in the Cape Floristic Region (CFR) lowlands, using ground-dwelling arthropods, specifically ants, as the focal taxon. Initially, base-line information of arthropods and in particular ants was obtained. Sampling arthropods generally involves a large sample effort. Therefore maximizing sampling effort for ants in the CFR was investigated by trapping ground-dwelling ants at a single locality. Doubling the number of grids of pitfall traps was found to be more effective in trapping a greater number of species than doubling the duration of sampling. Therefore increasing spatial sampling intensity rather than sampling duration maximizes sample effort for CFR ants. Also, the seasonal changes of ground-dwelling arthropods, including ants, were determined by sampling four times during the year at a single locality. Overall arthropod abundance was found to peak in summer while dropping to a minimum in winter. This pattern was mirrored by that of the ants, indicating that ant results have a broader relevance than to ants only. The ground-dwelling fauna was dominated by ants emphasizing their importance in the CFR lowlands, and demonstrating that ants are an appropriate flagship taxon for epigaeic arthropod diversity in the CFR. Finally the contribution of remnants in human-influenced areas to the conservation of the CFR was investigated. A nested hierarchical approach was used, where five localities were selected across the CFR, each containing one reserve site and one site with natural remnants. Ants were sampled, along with environmental variables, namely weather, vegetation and soil. Overall, remnants were found to support similar ant assemblages to those of reserves. However for individual localities some remnants were significantly different to their reserve counterparts. Differences in ant assemblages were found to be greater between localities than between reserves and remnants. The relatively high heterogeneity of ants found in this study emphasizes the conservation significance of invertebrates along with that of plants in the CFR. Remnants clearly show the potential to conserve ant assemblages, however correct management is needed for these areas to maximize their potential. Disturbances such as the presence of the invasive Argentine ant and increasing soil nutrients by fertilization, pose a distinct threat to the ability of remnants to conserve ant assemblages. This study has shown that remnants currently support ant assemblages representative of those present in the CFR today. Therefore, some remnant patches of habitat in agricultural areas currently do contribute highly to the conservation of a functional important taxon in this global biodiversity hotspot, and if managed correctly, may continue to do so in the future. / AFRIKAANSE OPSOMMING: Die vernietiging en fragmentering van habitatte maak die bewaring van biodiversiteit al hoe meer van ‘n uitdaging. Alhoewel natuur reservate reeds meer as 10 % van die aarde se oppervlak beslaan is dit duidelik dat meer gedoen sal moet word vir die lang-termyn voortbestaan van spesies. Dus word die fokus van biodiversiteit-bewaring toenemend gerig op bewaring van natuurlike en semi-natuurlike fragmente in menslik-beinvloede gebiede. Die doel van hierdie studie was om te bepaal wat die bydrae van fragmente van natuurlike veld in menslik-beinvloede gebiede is tot die bewaring van die streek. Dit is gedoen deur van grond-lewende geleedpotiges en spesifiek, miere in die Kaapse floraryk (CFR) gebruik te maak. Aanvanklik is kennis ingewin oor die geleedpotiges en spesifiek miere in die omgewing. Omdat die versameling van geleedpotige diere gewoonlik baie moeite vereis is ‘n maksimum steekproef gedoen by ‘n enkele lokaliteit. Daar is gevind dat ‘n verdubbling van die aantal ruitsteekproefnemings met vanggate meer effektief is om miere te vang as ‘n verdubbling in die tydperiode wat vanggate oop is. Dus, is ‘n hoër ruimtelike steekproef intensiteit meer effektief in vergelyking met ‘n langer tydsduur vir miere in die CFR. Die seisoenale veranderinge van grond-lewende geleedpotiges, sowel as miere, was ook bepaal. Dit was gedoen deur vier seisoenale steekproewe te doen by ‘n enkele lokaliteit. Die totale geleedpotige-talrykheid was die meeste gedurende die somer en die minste in die winter. Die miertalrykheid het ook hierdie patroon weerspieël. Dit dui daarop dat veranderinge in mier versamelings van breër belang is vir alle grondlewende geleedpotiges. Miere was die dominante grond-lewende geleedpotiges en beklemtoon die belangrikheid van miere in die CFR, sowel as hulle toepaslikheid as vlagskip taksa vir grond-lewende geleedpotige diversiteit in die CFR. Laastens was die bydrae van gefragmenteerde natuurlike veld in menslik–beinvloede gebiede tot die bewaring van die CFR ondersoek. ’n Krimpende/ genestelde hiërargies benadering is gebruik in vyf geselekteerde lokaliteite, elk het bestaan uit ‘n area in ‘n natuur reservaat en ‘n area in ‘n naasliggende fragment. Miere was versamel saam met ‘n verskeidenheid omgewings veranderlike, naamlik weer, plantegroei en grond. In die algemeen is gevind dat fragmente en reservate gelyksoortige mier versamelings het. Daar was wel gevind dat party fragmente aansienlik verskillend was van die reservaat teenstuk. Verskille in mier versamelings tussen lokaliteite was groter as verskille tussen reservate en fragmente. Die relatief hoë heterogeniteit van miere beklemtoon die bewaringsbelang van invertebrate saam met dié van plante in die CFR. Dit is duidelik dat fragmente wel ‘n potensiale bydrae kan maak om die mier versamelinge te bewaar, maar gepaste bestuur is nodig om hierdie potentiaal te maksimaliseer. Versteurings soos die teenwoordigheid van die indringer Argentynse mier en toenemende grondvoedingstofkonsentrasie as gevolg van bemesting is ‘n groot bedreiging tot die vermoë van fragmente om mier versamelings te bewaar. Hierdie studie wys dat mier versamelings in gefragmenterde areas verteenwordigend is van die algemene mier versamlings wat op die oomblik in die CFR is. Dus lewer party fragmente in landbou gebiede op die oomblik ‘n wesenlike bydrae tot die bewaring van ‘n funksioneel belangrike takson in hierdie globale biodiversiteitsbrandpunt en die bydra sal volhoubaar wees met korekte bestuur.