Browsing by Subject "biodiversity"
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- ItemRestrictedA preliminary survey and analysis of the spatial distribution of aquatic invertebrates in the Okavango Delta, Botswana(2007) Dallas, Helen F; Mosepele, BeldaThe spatial distribution of aquatic macroinvertebrates in the Okavango River Delta, Botswana, was investigated during the low-water period in February 2003. This complements an earlier study undertaken during high-water in June 2000. Seventy-five samples were taken in a range of aquatic habitats at 29 georeference points in four focal areas: Upper Panhandle (UPH), Lower Panhandle and Guma Lagoon (LPH), Moremi Game Reserve/Xakanaka (MGR), and Chief's Island (CI). Over 180 morphospecies (approximately 63 families) were recorded during the survey. Multivariate analyses of macroinvertebrate assemblages indicated that assemblages in each of the four focal areas were at least 54% similar at morphospecies level, and 71% similar at family level, although some taxa were more or less common in different areas. Differences in macroinvertebrate assemblages were observed amongst different habitat types, with differences most pronounced between the deltaic habitats and isolated seasonally-flooded pools and temporary rain-filled pools in MGR and CI. The highest number of taxa was recorded in the MGR (125), followed by the UPH (96), CI (93) and the LPH (89) areas. The most families were recorded in the Hemiptera (11), followed by Mollusca (10), Diptera (nine), Coleoptera (nine), Crustacea (six), Ephemeroptera (six) and Odonata (four). Three families of Hirudinea and Trichoptera, and one family of Lepidoptera, were also recorded. Hydracarina were common but not identified beyond order, while Oligochaeta were less frequently recorded. With respect to the different aquatic habitats sampled, the highest number of taxa was recorded in marginal vegetation in the channels and lagoons, although inundated floodplains, floating vegetation and marginal vegetation in backwaters also supported many taxa. The fewest taxa were recorded in sediment. This survey, whilst representing a 'snapshot' of the system under low-water conditions, highlights the importance of maintaining a mosaic of aquatic habitats in the Delta. Further studies would enhance our knowledge of the aquatic macroinvertebrate biodiversity of the Okavango Delta, thereby contributing to its conservation.
- ItemOpen AccessAssessing the utility of open-source data in exploring benthic biodiversity in mining concessions off the South African coast(2022) Lennox, Emma; Karenyi, NatashaExtractive activity in the marine realm is a well-recognised pressure on the marine environment, particularly for the preservation of biodiversity (Majiedt et al. 2019). Data that are openly available, from repositories, guides and within other studies, are a growing resource available to researchers, with the benefits including accessibility, cost effectiveness, and access to long-term data. Data were sourced from the Ocean Biodiversity Information System (OBIS), Offshore Invertebrate Field Guide (Atkinson and Sink) and mining impact datasets (Steffani and Pulfrich 2008, Cook 1995, 1996, 1997 and 1999) to explore the utility of openly available data in exploring benthic biodiversity within two mining concessions on the west and south coasts of South Africa. Lists of benthic taxa were generated, and biodiversity quantified using quantitative measures (species richness, Shannon-Wiener index) and multivariate analyses, where possible. Each dataset provided a different aspect of the benthic biota within the concessions, including taxonomic data (i.e., species, genera, class, phylum) that are easily quantified within a particular region. Long-term data available from OBIS allowed for patterns to be visualised over time, although this was constrained by data gaps, differences in methodology and lack of metadata, for instance. For the purposes of assessing how anthropogenic pressure impacts biodiversity, the utility of open-source data was limited to datasets that considered the impacts of mining in particular. To consider the impacts different types of extractive activity have on biodiversity at a finer scale, in-situ sampling of the proposed area is substantially more beneficial than open-source data in assessing the particular ways ecosystems are impacted by anthropogenic activity.
- ItemOpen AccessCitizen Science - building an early warning system for biodiversity(2012) Underhill, LesLecture series coordinated by Professor Les Underhill, Director, Animal Demography Unit, Department of Zoology, UCT. This lecture series studies a number of animal demography initiatives underway in South Africa, and highlights the ways in which members of the public can get involved in scientific and conservation efforts by volunteering their time. This lecture series will be of interest to aspiring citizen scientists, zoologists and others working in the field of biodiversity.
- ItemOpen AccessExtinctions: Past and Present Week 1 - In the beginning(2017-03-17) Chinsamy-Turan, AnusuyaIn this video, Professor Anusuya Chinsamy-Turan discusses the early geological record in terms of rock and fossil formation. She discusses how fossilisation occurs in plants and animals, and how the fossil record only records a portion of all the lifeforms that have existed on earth. She discusses how scientists can use the fossil record to explore the history of life on earth and trace current biodiversity to what existed in the past. She then discusses the different epochs or eras in the development of life from the earliest forms of life, to the emergence of multicellular organisms, to the emergence of life on land. This is video 3 in Week 1 of the Extinctions: Past and Present MOOC.
- ItemOpen AccessExtinctions: Past and Present Week 3 - Before and after the End Permian Extinction Event(2017-03-17) Chinsamy-Turan, AnusuyaIn this video, Professor Anusaya Chinsamy-Turan introduces the topic of the End Permian extinction which took place 252 million years ago and was the third and largest mass extinction event. She introduces postdoctoral researcher Michael Day who will discuss the Guadalupian extinction. She then introduces palaeontologist/geologist Roger Smith about the extraordinary mammal-like reptiles from South Africa. Finally, she introduces paleobotanist John Anderson about his research into the plant and insect biodiversity that spans the Permian-Triassic boundary.
- ItemOpen AccessExtinctions: Past and Present Week 4 - Extinctions and diversifications(2017-03-17) Chinsamy-Turan, AnusuyaIn this video, Professor Anusuya Chinsamy-Turan reflects on the topic of the End Triassic event and the content discussed in previous videos with guests. She introduces the topic to be discussed in subsequent videos, the current biodiversity crisis. This is video 8 in Week 4 of the Extinctions: Past and Present MOOC.
- ItemOpen AccessExtinctions: Past and Present Week 4 - Recovery of ecosystems(2017-03-17) Chinsamy-Turan, AnusuyaIn this video, Professor Anusuya Chinsamy-Turan introduces the Triassic period in detail. She provides examples of species which emerged and dominated during this time (such as the early dinosaurs) and some of the theories about the cause of the End Triassic extinction event, which devastated terrestrial and marine species. This is video 1 in Week 4 of the Extinctions: Past and Present MOOC.
- ItemOpen AccessExtinctions: Past and Present Week 5 - Our world today: facing a sixth extinction?(2017-03-17) Chinsamy-Turan, AnusuyaIn this video, Professor Anusuya Chinsamy-Turan introduces the topic of the current biodiversity crisis. She discusses how the previous five extinctions allow us to see how our planet and biodiversity responded to environmental crises in the past. She introduces the guests she will interview about the topic: Peter Ryan, Muthama Muasya, Timm Hoffman, Denham Parker, and Lindsey Gillson.
- ItemOpen AccessThe influence of fire-grazer interactions on forb communities in a highveld grassland(2017) Parrish, Margaret Doris; Archibald, Sally; Midgley, Jeremy JIn southern Africa, disturbance contributes to the heterogeneity of grassland and savanna ecosystems. Fire and grazing act as the primary disturbances in these systems, and interactions between the two are common. As such, an understanding of the relationship between fire and grazing is essential for the conservation of biotic diversity and the production of high-quality forage for game and livestock. Frequent fires followed by concentrated grazing have been shown to facilitate patches of short, palatable grasses ("grazing lawns") within grassland and savanna landscapes. The effects of grazing lawn management on other aspects of biodiversity have received little attention. Forbs (non-graminoid, herbaceous plants) are an important component of grassland ecosystems, but how they respond to disturbance is largely unknown. This study compared changes in forb communities on and off of firebreaks (an extreme example of a grazing lawn) in a high altitude mesic grassland. Native herbivore biomass was significantly higher on firebreaks than in the surrounding lightly grazed matrix and the firebreaks, while more compacted, did not show significant signs of degradation. There were no significant differences in forb abundance or richness between annually burned and intermittently burned plots, and there was no species turnover associated with the annually burned, heavily grazed treatment. Speciesspecific differences in functional traits on annually burned and intermittently burned plots were likely a function of light limitation, as mammalian palatability scores were nominal. Ultimately, ten years of intensive fire and grazing have had minimal impact on forb communities in a high altitude mesic grassland. The results indicate that in this type of Highveld grassland, heavily grazed and annually burned patches are not detrimental to the forb community and clearly enhance habitat diversity for grazers.
- ItemOpen AccessUnderstanding philanthrocapitalism and its impact on private nature reserves: A case study of Gorongosa, Mozambique(2022) Ochs, Tobias; Mbatha, PhilileAn increasing body of literature reveals that powerful businesspeople have a long history of using their wealth for the benefit of the greater common good. With philanthrocapitalism, a new generation of hands-on donors that have made incredible fortunes within business sectors like information technology or finance, are taking on the world's most pressuring social and environmental problem, willing to change the way of giving and enhancing traditional philanthropy. The rich entrepreneurs turned philanthropists are applying their skills and talents that have made them successful in business and infusing the charity sector with corporate tools and strategies and are getting personally engaged and using political and social networks to leverage their efforts. Driven to find solutions to the world's most severe problems, philanthrocapitalists tend to target problems that cut across national boundaries, such as AIDS, Malaria, illiteracy, and population growth. Next to these familiar fields such as health and education, philanthropists are also increasingly engaging in nature conservation. By establishing private nature reserves or taking over failed state-run nature reserves, elite donors are increasingly featuring neoliberal conservation and intervene in political ecology particularly in biodiversity hotspots in the global South. Notwithstanding philanthrocapitalism growing prominence and significance, broader public debates and academic literature is just emerging in recent years and the impact on nature conservation has received little scholarly attention. By examining the case of the Gorongosa Project (GP), a transnational nature conservation project that was established by U.S. multimillionaire Greg Carr in Mozambique, this thesis seeks to illustrate: a) how philanthrocapitalism influences nature conservation, b) how philanthrocapitalistic conservation projects work in practice and, c) enhance understanding about the implications of philanthrocapitalism in conservation governance, recognising its advantages and limitations. The thesis further seeks to contribute to the academic discourse as the far-reaching ventures of Western philanthrocapitalists have provoked a controversial debate. Advocates such as economists, journalists and political organisations argue that the financial power, unique business skills, resources and networks enable philanthrocapitalists to contribute to solving global issues more efficiently than other stakeholders. In contrast, critics from political or social sciences or conservation point out the increasing influence that wealthy philanthropists have on global policymaking as well as social and political agendas and have raised concerns about democratic values and power and wealth inequalities.
- ItemOpen AccessUse and usefulness of measures of marine endemicity in South Africa(2016) Griffiths, Charles L; Robinson, Tamara BAbstract Numerous authors have cited numbers, or proportions, of endemic species within South(ern) African marine taxa, but comparisons between these statistics are confounded by differing definitions of regional boundaries and differences among data sets analysed. These have resulted in considerable variations in published endemicity data, even within the same taxonomic group. We tabulated and compared key endemicity statistics for regional marine taxa and explained biases in the data sets. The most comprehensive data sets available give overall marine endemicity within the national boundaries of South Africa as 28–33%, but estimates within individual taxa making up these totals vary enormously, from 0% (Aves, Mammalia) to over 90% (Polyplacophora). We also examined published data documenting localised endemicity patterns around the coastline. These consistently show the highest numbers of endemics occurring along the South Coast. There are logical biogeographical reasons to expect this trend, but endemicity rates are also inherently biased by distance from defined political boundaries and by differing sampling effort locally and in neighbouring countries. Range restriction is considered a better measure of conservation status than endemicity, although it is far less often used and yields very different patterns. Properly and consistently calculated measures of national endemicity do, however, retain significant conservation value, and the rates for South Africa marine biota are high relative to other regions globally, being exceeded only by New Zealand and Antarctica. It is important that when citing endemicity statistics, researchers and conservation managers understand the definitions used and the many constraints under which these measures are derived.