1,298 research outputs found
The edge of the periphery: situating the â Khomani San of the Southern Kalahari in the political economy of Southern Africa
This is an Accepted Manuscript of an article published by Taylor & Francis in African Identities on 14/04/16, available online: http://www.tandfonline.com/10.1080/14725843.2016.1154813In this article, we situate the Southern Kalahari San within the political economy of Southern Africa and within the world system. Here we draw on and critique modernization theory as a model of explanation for the lack of development found locally. In the Southern Kalahari, the â Khomani San won a massive land claim that should have empowered and enabled local development. Yet they remain largely impoverished, while seeking out a meaningful life on the edge of the capitalist world system. Within states, contradictions remain as local diversity continues to be reproduced and modernity itself is reproduced as local diversity. The research is premised on empirical fieldwork conducted in the Southern Kalahari in 2013 and supported by a series of earlier field research over the previous five years. The San of the Southern Kalahari are not resisting modernity but drawing on aspects of it selectively for their own vision of meaningful development
Ons is Boesmans: commentary on the naming of Bushmen in the southern Kalahari
This paper examines academic debates about the nomenclature of the San in light of recent ethnographic data. Academic debates centre around two aspects: the apparent complicity of the term âbushmanâ in construing the San as lower on the hierarchy of race and class; and the construction of the San as being in close contact with animals and nature. Academics have sought to resolve this dilemma of complicity by adopting self-referential terms, which would allow them to overcome the effacement of cultural and linguistic variation. Critically, the paper argues that this turn to self-referential terms is problematic in the case of the â Khomani San of the southern Kalahari because the San themselves claim âbushmanâ as their identity. The analysis suggests that the â Khomani San claim this name for themselves in a context of developmental needs. Thus, â Khomani San chose the name âBushmanâ for themselves because it can be commoditised
Modelling the impact of climate change on woody plant population dynamics in South African savanna
BACKGROUND: In Southern Africa savannas climate change has been proposed to alter rainfall, the most important environmental driver for woody plants. Woody plants are a major component of savanna vegetation determining rangeland condition and biodiversity. In this study we use a spatially explicit, stochastic computer model to assess the impact of climate change on the population dynamics of Grewia flava, a common, fleshy-fruited shrub species in the southern Kalahari. Understanding the population dynamics of Grewia flava is a crucial task, because it is widely involved in the shrub/bush encroachment process, a major concern for rangeland management due to its adverse effect on livestock carrying capacity and biodiversity. RESULTS: For our study we consider four climate change scenarios that have been proposed for the southern Kalahari for the coming decades: (1) an increase in annual precipitation by 30â40%, (2) a decrease by 5â15%, (3) an increase in variation of extreme rainfall years by 10â20%, (4) and increase in temporal auto-correlation, i.e. increasing length and variation of periodic rainfall oscillations related to El Niño/La Niña phenomena. We evaluate the slope z of the time-shrub density relationship to quantify the population trend. For each climate change scenario we then compared the departure of z from typical stable population dynamics under current climatic conditions. Based on the simulation experiments we observed a positive population trend for scenario (1) and a negative trend for scenario (2). In terms of the projected rates of precipitation change for scenario (3) and (4) population dynamics were found to be relatively stable. However, for a larger increase in inter-annual variation or in temporal auto-correlation of rainfall population trends were negative, because favorable rainfall years had a limited positive impact due to the limited shrub carrying capacity. CONCLUSIONS: We conclude that a possible increase in precipitation will strongly facilitate shrub encroachment threatening savanna rangeland conditions and regional biodiversity. Furthermore, the negative effects found for positive auto-correlated rainfall support current ecological theory stating that periodically fluctuating environments can reduce population viability because species suffer disproportionately from poor environmental conditions
Simulacral, genealogical, auratic and representational failure: Bushman authenticity as methodological collapse
This article engages with the concept of authenticity as deployed in anthropology. The first section critiques authenticity as a simple reference to cultural purity, a traditional isomorphism or historical verisimilitude or as an âethnographic authenticityâ. Demarcation of authenticity must take into account philosophical literature that argues that authenticity is an existential question of the âmodernâ era. Thus, authenticity is offered to us as individuals as a remedy for the maladies of modernity: alienation, anomie and alterity. Authenticity is then discussed as a question of value within an economy of cultural politics that often draws on simulacra, creating cultural relics of dubious origin. The final section discusses various methodological failures and problematiques that are highlighted by the concern for, and scrutiny of, authenticity. The first is the simulacral failure. The subjects of anthropology are mostly real flesh-and-blood people-on-the-ground with real needs. In contrast is the simulacral subject, the brand, the tourist image, the media image or the ever-familiar hyper-real bushmen. Lastly, the article considers what Spivak calls âwithholdingâ â a resistance to authentic representation by the Other. Resistance suggests a need for a radically altered engagement with the Other that includes both a deepening, and an awareness, of anthropology as a process of common ontological unfolding
Movement patterns and athletic performance of leopards in the Okavango Delta
Although leopards are the most widespread of all the big cats and are known for their adaptability, they are elusive and little is known in detail about their movement and hunting energetics. We used high-resolution GPS/IMU (inertial measurement unit) collars to record position, activity and the first high-speed movement data on four male leopards in the Okavango Delta, an area with high habitat diversity and habitat fragmentation. Leopards in this study were generally active and conducted more runs during the night, with peaks in activity and number of runs in the morning and evening twilight. Runs were generally short (less than 100 m) and relatively slow (maximum speed 5.3 m sâ1, mean of individual medians) compared to other large predators. Average daily travel distance was 11 km and maximum daily travel distance was 29 km. No direct correlation was found between average daily temperature and travel distance or between season and travel distance. Total daily energy requirements based on locomotor cost and basal metabolic rate varied little between individuals and over time. This study provides novel insights into movement patterns and athletic performance of leopards through quantitative high-resolution measurement of the locomotor, energetic, spatial and temporal movement characteristics. The results are unbiased by methodological and observational limitations characteristic of previous studies and demonstrate the utility of applying new technologies to field studies of elusive nocturnal species
Land surface response to climate change forcing over Southern Africa
The land surface is important to the climate system for the exchanges of moisture, momentum and heat. Momentum, radiation, and sensible and latent heat fluxes between the atmosphere and the surface will likely affect atmospheric dynamics, temperature, precipitation and humidity fields (Sato et ai., 1989). These may subsequently feed back into the land surface processes as part of a cyclical system. Therefore it is evident that our livelihood is largely dependent on interactions and exchanges between the land surface and climate system (Henderson-Sellers et ai., 1993) and it is thus essential that we gain a better understanding of the interactive sensitivity. This is of particular relevance in the context of the portended future global climate change. In the present study the interactions between the land surface and the atmosphere are considered over the southern African region. This region has a climate showing a high degree of spatial and temporal variability, most notably with rainfall. Regional climates are characterised by summer, winter and all-year-round rainfall. There are steep vegetation gradients and a wide range of vegetation types adapted to suit the variable climate. These factors, combined with the societal implications of changes in the climate and land surface systems, make southern Africa a challenging and important study domain for examining the sensitivity between the different elements of the atmosphere and biosphere. This research makes use of a biosphere model driven by climate change data derived from a general circulation model (GCM). Regions susceptible and sensitive to changes on an annual and seasonal basis are identified and examined. The thesis comprises 8 chapters. The first chapter, Chapter 1, provides some background information on climate change, biosphereatmosphere interactions, GCMs and transient simulations, vegetation models and vegetation representation over southern Africa. This chapter also sets out the research objectives. The following chapter, Chapter 2, introduces the atmospheric GCM model data from the Hadley Centre Model (HadCM2) used in the analysis. The chapter additionally provides a detailed description of the biosphere model, the Integrated Biosphere Simulator (IBIS). Chapter 3 examines the Hadley Centre HadCM2 GCM input data used in driving the biosphere model, while Chapter 4 presents the input forcing data and configuration of the IBIS model. In Chapter 5 the results of the IBIS model simulation are examined on the annual scale and in Chapter 6 the results are examined on the seasonal scale. Some of the implications of climate change are considered in Chapter 7. This chapter also places the HadCM2 GCM model data used in driving IBIS into the context of the latest emissions scenarios. In the final chapter, Chapter 8, an overview summary is provided and conclusions are drawn
Movement ecology of gemsbok in the central Kalahari in response to vegetation greenness as assessed by satellite imagery
Centre of African Ecology
Animal, Plants and the Environmental Sciences
University of the Witwatersrand, Johannesburg.Arid African savannas experience seasonal, variable rainfall, resulting in unpredictable patterns in vegetation distribution. Understanding the spatio-temporal variability in primary productivity and the resulting behavioural responses of native herbivores is essential for the analysis of the vulnerability of savanna ecosystems to climatic and human-induced threats. The Central Kalahari Game Reserve (CKGR), Botswana, is open to free-ranging wildlife to its south and west. The mostly homogeneous dune landscape is interspersed with valley and pan systems, which deviate considerably from dune regions in their soil and vegetation structures. I assessed the phenology of green vegetation across the pan-valley and dune habitats of the northern CKGR, using Normalized Difference Vegetation Index (NDVI) imagery, and related variations in greenness to the ecology of gemsbok (Oryx gazella), a herbivore species that is highly adapted to arid conditions. Eight female gemsbok were collared in the northern CKGR, and their patterns of habitat selection and responses to three greenness measures (NDVI, ÎNDVI and Relative Greenness) were assessed using logistic regression models. Gemsbok 12-hour displacement distances for each herd were compared seasonally to assess whether gemsbok in the northern CKGR differ in their movement strategies depending on the prevailing environmental conditions at that point in time and space.
The northern CKGR experiences high inter-annual variability in NDVI greenness and phenology. Pan-valley and dune habitats did not have significantly different rates of green-up or green season durations, but dune habitats had higher NDVI levels. Patches with the highest greenness levels showed little spatial persistence from year to year. Gemsbok did not select for higher NDVI or ÎNDVI, but they selected for categories of relative greenness that were higher than the lowest relative greenness level. Gemsbok selected pan-valleys over dunes during the green season, but were not selective during the brown season, probably as a result of the loss of green grasses in pan-valley habitats during this period. Finally, gemsbok had no specific general trend in seasonal displacement distances. Gemsbok in the CKGR are likely to be opportunistic feeders, and herds probably made varying behavioural decisions based on their immediate environmental conditions
Provenance of Kalahari Sand: Paleoweathering and recycling in a linked fluvial-aeolian system
We here review what is known about the dunefields and fluvial systems of the Kalahari Basin in terms of geological setting and Quaternary dynamics and set out what has been hypothesized about the provenance of Kalahari sand so far. Previous work has tackled this problem by applying a limited number of techniques (mostly sediment textures and heavy minerals) to parts of the large dryland. The generally highly quartzose mineralogy of aeolian dunes and their compositional variability have been only broadly evaluated and several sedimentological issues have thus remained controversial, including the relative role played by fluvial processes versus aeolian reworking of older sediments and weathering controls. This reveals a need for a systematic provenance study that considers the entire basin. For this reason, here we combine original petrographic, heavy-mineral, and detrital-zircon geochronology data with previously published clay-mineral, geochemical, and geochronological information to present the first comprehensive provenance study of the vast Kalahari sand sea.
Our multi-proxy dataset comprises 100 samples, collected across the Kalahari Basin from 11°S (NW Zambia) to 28°S (NW South Africa) and from 15°E (Angola) to 28°30âČW (Zimbabwe). Kalahari aeolian-dune sand mostly consists of monocrystalline quartz associated with durable heavy minerals and thus drastically differs from coastal dunefields of Namibia and Angola, which are notably richer in feldspar, lithic grains, and chemically labile clinopyroxene. The western Kalahari dunefield of southeastern Namibia is distinguished by its quartz-rich feldspatho-quartzose sand, indicating partly first-cycle provenance from the Damara Belt and Mesoproterozoic terranes. Within the basin, supply from Proterozoic outcrops is documented locally. Composition varies notably at the western and eastern edges of the sand sea, reflecting partly first-cycle fluvial supply from crystalline basements of Cambrian to Archean age in central Namibia and western Zimbabwe. Basaltic detritus from Jurassic Karoo lavas is dominant in aeolian dunes near Victoria Falls.
Bulk-sediment petrography and geochemistry of northern and central Kalahari pure quartzose sand, together with heavy-mineral and clay-mineral assemblages, indicate extensive recycling via aeolian and ephemeral-fluvial processes in arid climate of sediment strongly weathered during previous humid climatic stages in subequatorial Africa. Distilled homogenized composition of aeolian-dune sand thus reverberates the echo of paleo-weathering passed on to the present landscape through multiple episodes of fluvial and aeolian recycling.
Intracratonic sag basins such as the Kalahari contain vast amounts of quartz-rich polycyclic sand that may be tapped by rivers eroding backwards during rejuvenation stages associated with rift propagation. Such an event may considerably increase the sediment flux to the ocean, fostering the progradation of river-fed continental-embankments, as documented by augmented accumulation rates coupled with upward increasing mineralogical durability in the post-Tortonian subsurface succession of the Zambezi Delta.
The Central Kalahari is not a true desert. It has none of the naked, shifting sand dunes that typify the Sahara and other great deserts of the world. In some years the rains may exceed twenty â once even forty â inches, awakening a magic green paradise.â Mark Owens, Cry of the Kalahari
Anthropogenic supply of nutrients in a wildlife reserve may compromise conservation success
In nutrient-poor wildlife reserves it has become common-practice to provide supplemental mineral resources for wildlife. Yet, the impacts of anthropogenic mineral supplementation on large herbivore nutrition, behaviour, and subsequent impact on ecosystem processes have received little attention. Here, we examine the contribution of anthropogenic mineral lick provision to wildlife nutrient intake across a community of mammalian herbivores (>10 kg) in the southern Kalahari Desert. Based on predicted daily nutrient intake and a faecal nutrient assessment, many large herbivore species appear deficient in phosphorus (P), sodium (Na), or zinc (Zn). For these nutrients, anthropogenic salt and mineral licks constitute an important source of nutrient intake helping to reduce or overcome requirement deficits. Larger-bodied species disproportionately consumed licks, acquiring more nutritional benefits. A comprehensive assessment of animal body condition indicated that, in general, large herbivores display good health. However, bulk grazers, non-ruminants and females displayed poorer body condition. We discuss how provisioning of anthropogenic mineral licks may inflate large herbivore populations beyond the long-term carrying capacity of the reserve by decoupling wildlife fecundity from nutrient-related feedbacks on population growth. Over time, this could compromise ecosystem integrity through habitat degradation, modified species interactions and trophic cascades. Based on results presented here, it is clear that anthropogenic provisioning of mineral licks should be considered cautiously by wildlife managers aiming to conserve natural processes in landscapes
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