Browsing by Subject "Climate"

Now showing 1 - 4 of 4
  • No Thumbnail Available
    Item
    Open Access
    A climate change vulnerability assessment of 58 Richtersveld plant species
    (2025) Pather, Keyura; Foden, Wendy; Cunningham, Susan; Raimondo, Domitilla
    The Richtersveld is the northernmost region of the Succulent Karoo and is located in the north-western region of South Africa's Northern Cape Province. This region has an incredible arid plant diversity, with both the highest succulent plant diversity and highest rate of endemism in an arid area, globally. It forms part of both a global biodiversity hotspot and a UNESCO world heritage site. However, it is already experiencing significant climate change exposure which is predicted to worsen. Changes in the area's climate are also interacting synergistically with other anthropogenic pressures including mining, poaching and agriculture. The threats to this area, including climate change, are documented but knowledge gaps still remain – especially with regards to plants and climate change vulnerability. In this study I aimed to find which Richtersveld species are the most vulnerable to climate change while trialling a relatively novel approach in this context. I used a trait-based assessment with correlative species distribution model outputs to assess the sensitivity, adaptive capacity and exposure of 58 plant species occurring within the Richtersveld National Park. This included assessing biological, ecological, environmental and spatial traits of species that contribute to climate change vulnerability. Traits were scored based on literature, expert opinion and correlative modelling outputs. Trait scores were then combined using both additive and ordinal methods, creating a best-case scenario where unknowns were assumed to have ‘low' scores, and a worst-case scenario when these were assumed to be ‘high'. These scenarios were applied to both the ordinal and additive scoring methods. For the additive scoring method, there was an additional consideration – trait weighting. It would be inaccurate to assume all traits hold the same importance in determining a species' vulnerability to climate change. Each trait was assigned a weighting based on literature and expert opinion and applied in an additional weighted scoring approach. Therefore, each species had a total of six climate change vulnerability scores: a best-case ordinal, a worst-case ordinal, a best-case unweighted additive, a worst-case unweighted additive, a best-case weighted additive and a worst-case weighted additive score. Under the worst-case ordinal scoring method, 34 species (59 %), were scored as highly vulnerable to climate change. The most vulnerable species were those that consistently scored high vulnerability scores, across all six scoring methods. This included Cheilanthes namaquensis (Not endemic to the region nor the park and Least Concern), Trachyandra ardimontana (almost endemic to park and Endangered), Albuca etesiogaripensis (almost endemic to park and Data Deficient), Ruschia glauca (almost endemic to park and Endangered) and Schwantesia herrei (Richtersveld endemic and Least Concern). I also found a mismatch between species' Red List status and their scores in my climate change vulnerability assessment. This suggests that highly climate change vulnerable species identified in this study currently have a low Red List threat status assigned to them by the responsible conservation organisation. This finding could mean that their status does not accurately reflect their level of conservation risk – especially if climate change is not accounted for. This can cause them to be overlooked in terms of conservation resource provision and decision- making. The IUCN Red List Version 16 Section 12 provides guidelines for assessing climate change vulnerability and its application in determining a species' threat status to climate change. However, its development is relatively recent, and its use is limited, possibly due to the data and technical expertise required. My study provides a possible example of how, even in highly biodiverse region with low data availability, climate change vulnerability assessments may be carried out, and of the value for preventing extinctions. The highest concentration of climate change vulnerable species were found to be in the central western and northern areas of Richtersveld National Park. The spatial representation of these data may aid where within the Park conservation and management can be prioritized. In conclusion, I trialled an approach that has not previously been applied for Richtersveld plants. The approach produced predictions of climate change vulnerability that could be used for conservation. The approach used in this study helped identify species and areas to which climate change conservation measures could be applied. This approach can be applied to other arid areas and aid in climate- related conservation, including in section 12 of the Red Listing Guidelines (Version 16).
  • No Thumbnail Available
    Item
    Open Access
    Developing a framework for assessing equity in contributions to the global goal on adaptation as part of the global stocktake
    (2023) Barkai, Kalia; Winkler, Harald
    The global stocktake (GST) aims to assess collective progress in mitigation, adaptation, and the means of implementation and support as outlined in Article 14 of the Paris Agreement. The stocktake will be undertaken considering equity and the best available science. As a result, the GST requires a framework for assessing equity in mitigation, adaptation, and support. While mitigation has been more frequently defined based on allocations of “fair shares” in terms of emissions responsibility and targets, it is less clear how equity can be assessed in contributions to the global goal on adaptation (GGA). This is due to the diversity of pathways for enhancing adaptive capacity, strengthening resilience, and reducing vulnerability to climate change. Equity in the GGA is highly intertwined with issues of justice as those least responsible for climate change are most vulnerable to its impacts and have little to no resources for adaptation. Moreover, although adaptation actions are taken on the local level, the GGA is a collective goal. An effective framework for an equity assessment in the GST would have further benefits, including: guiding equity-driven approaches to National Adaptation Plans (NAPs), acting as an ambition enabler for the Parties who believe that climate change efforts are fairly shared, and highlighting how equity considerations can be improved between the GSTs. This thesis raises and investigates the following questions: what metrics exist for assessing equity in national contributions to the GGA? how appropriate are existing indicators for assessing equity in national contributions to the GGA? and what could an effective framework for assessing equity in national contributions to the GGA look like? This research aims to answer these questions through a systematic review of literature on equity metrics in adaptation programmes on the national and international scale. Building from a narrative synthesis and keyword analysis of the references collected, this research develops a rubrics-based framework for assessing equity in the GGA as part of the GST. The framework is founded on four dimensions of equity: distributive, procedural, recognitional, and intergenerational justice. To test the framework's applicability to a specific contribution to the GGA, and to inform the framework's effectiveness for collective assessment in the GST, it is applied to the South African National Climate Change Adaptation Strategy (NCCAS). A summary diagram is developed which demonstrates that whilst South Africa's NCCAS shows some promise to mainstreaming equity in the distributive justice dimension, it could still be more comprehensive about the plans relating to procedural and recognitional justice, and fails to achieve equity in intergenerational justice
  • Thumbnail Image
    Item
    Open Access
    Diversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant’s foot tubers
    (2016) Maurin, Olivier; Muasya, A Muthama; Catalan, Pilar; Shongwe, Eugene Z; Viruel, Juan; Wilkin, Paul; van der Bank, Michelle
    Abstract Background Dioscorea is a widely distributed and highly diversified genus in tropical regions where it is represented by ten main clades, one of which diversified exclusively in Africa. In southern Africa it is characterised by a distinct group of species with a pachycaul or “elephant’s foot” structure that is partially to fully exposed above the substrate. In contrast to African representatives of the genus from other clades, occurring mainly in forest or woodland, the pachycaul taxa and their southern African relatives occur in diverse habitats ranging from woodland to open vegetation. Here we investigate patterns of diversification in the African clade, time of transition from forest to more open habitat, and morphological traits associated with each habitat and evaluate if such transitions have led to modification of reproductive organs and mode of dispersal. Results The Africa clade originated in the Oligocene and comprises four subclades. The Dioscorea buchananii subclade (southeastern tropical Africa and South Africa) is sister to the East African subclade, which is respectively sister to the recently evolved sister South African (e. g., Cape and Pachycaul) subclades. The Cape and Pachycaul subclades diversified in the east of the Cape Peninsula in the mid Miocene, in an area with complex geomorphology and climate, where the fynbos, thicket, succulent karoo and forest biomes meet. Conclusions Diversification out of forest is associated with major shifts in morphology of the perennial tuber (specifically an increase in size and orientation which presumably led them to become pachycaul) and rotation of stem (from twining to non-twining). The iconic elephant's foot morphology, observed in grasslands and thicket biomes, where its corky bark may offer protection against fire and herbivory, evolved since mid Miocene. A shift in pollination trait is observed within the forest, but entry into open habitat does not show association with reproductive morphology, except in the seed wing, which has switched from winged all round the seed margin to just at the base or at the apex of it, or has been even replaced by an elaiosome.
  • Thumbnail Image
    Item
    Open Access
    The adverse health effects associated with drought in Africa: working towards developing a vulnerability index
    (2020) Asmall, Taherah; Dalvie, Aqiel; Abrams, Amber
    Africa is uniquely vulnerable to the occurrence of drought. A rise in temperatures over Southern Africa occurs at almost twice that of the global rate. South Africa has begun to experience an increase in the frequency of drought, particularly in the Western and Eastern Cape. Droughts are associated with several health effects. The direct and indirect risks of climate change to human health have become a global concern. The most recent systematic review available on the adverse health effects associated with drought was published in 2013, and as such, an up-to-date review focusing on Africa is needed to inform a Cape Town specific health vulnerability index. This study aims to provide a review of available research exploring the association between drought and adverse health effects in Africa. The rationale for this study is to provide a solid research foundation from which a drought-specific health vulnerability index for Cape Town can be developed. A narrative review of original studies and published reviews was conducted. An extensive electronic literature search was performed using a combination of keywords, Medical Subject Heading (MeSH) terms and free text words. The Critical Appraisal Toolkit (CAT) was used to assess the quality of included studies. A total of 1922 publications were identified, of which twenty-four articles were included in this review. The main drought-related health effects that emerged were divided into 4 main categories: (1) drought and nutritional health including malnutrition, poor childhood health outcomes (wasting, stunting and underweight), mortality, anaemia, and nutritionrelated disability; (2) drought and food consumption including micronutrient deficiencies and motor neuron diseases; (3) drought and water-borne, water-washed and water- related diseases including cholera outbreaks, diarrhoeal diseases, protozoa parasite transmission, scabies outbreaks, trachoma, vector-borne disease outbreaks and malaria-related mortality; and (4) drought and health behaviours including health perceptions and health-seeking behaviours, HIV prevention and care behaviours and family planning practices. There was generally limited evidence in all health categories with several limitations. These limitations include studies with methodological weaknesses (e.g. a lack of comparison to a non-drought period), the singularity of published studies on health effects associated with drought and studies which did not account for potential confounders. While the evidence from the included studies is limited, this study highlights gaps in literature to encourage further research into understanding the direct and indirect impacts of drought on health, particularly in vulnerable groups. Furthermore, the results of this study emphasized the contextual factors which lower an individual's adaptive capacity and identified key indicators that can be used to begin to develop a broad framework for a vulnerability index