PhD Students

Felix Skhosana

Department of Botany and Zoology

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Woody encroachment is one of the most significant and complex phenomena impacting ecosystem functioning and services in arid and semi-arid savannas and grasslands worldwide. Felix’s project is therefore, looking at the dynamics of woody encroachment and its impact on ecosystem processes and services. It gives a global view on the impacts of woody encroachment on ecosystem services through a systematic review. It then narrows down to mapping woody encroachment hotspots in South Africa using remotely sensed aboveground woody biomass and canopy cover under the theory that areas of high woody encroachment are characterised by low woody biomass and high canopy cover. Due to a growing concern that woody encroachment may result in less water availability for plants and groundwater recharge we then investigate the impact on rainfall partitioning, into throughfall, stemflow and interception across a gradient of encroachment by Terminalia sericea and Dichrostachys cinerea at Wits Rural Facility in the Limpopo Province. Studies done in forests have shown that a significant amount of rainfall is lost through canopy interception, however, there is still a huge gap of such studies in encroached dry systems. He then concludes by upscaling these site-level results in time and space by using the adaptive Dynamic Global Vegetation Model (aDGVM).

Amukelani Maluleke

Department of Botany and Zoology

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Amukelani is working on carbon dioxide, water and turbulent energy exchanges between Nama-Karoo and Savanna type vegetation and the atmosphere. His project aims to improve the quantitative understanding of key ecosystem processes to characterise their temporal responses to variations in biophysical inputs (rainfall, temperature, radiation) with the application of the Eddy Covariance flux measurements and remotely-sensed vegetation indices. Linking these two measurement approaches allows the study to improve the spatial coverage of vegetation response assessments of semi-arid ecosystems and ultimately inform decision making about prioritising resource allocation towards climate change resilience in South Africa. He has three flux tower sites: Skukuza and Malopeni in the Kruger National Park; Benfontein in the Free State; and Middleburg in the Eastern Cape.

Zuzi Nyareli

Department of Botany and Zoology

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According to the Millennium Ecosystem Assessment, ecological infrastructure is increasingly being destroyed or transformed around the world, with detrimental implications for human well-being. At the heart of this deterioration is the changing land cover due to unsustainable land-use practices aiming at meeting the economic development needs of the country. Ecological Infrastructure (EI) as specified by the South African National Biodiversity Institute (SANBI) refers to naturally functioning ecosystems that provide valuable services to people, such as water and climate control, soil formation, and disaster risk reduction. Monitoring the long-term impacts of land cover change on the EI can provide a valuable starting point for understanding how the EI facilitates the delivery of ecosystem services over time. Zuzi aims to quantify the impacts of land cover change and climate change in Duiwenhoks catchment, Southern Cape, South Africa, over the past seven decades.

Maanda Raselabe

Department of Botany and Zoology
Google Scholar

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Maanda’s PhD is focused on assessing the overall performance of semi-arid C4 grasses and their potential distribution under changing climate conditions. This will be achieved by measuring their gross primary productivity response to different environmental variables, assessing their eco-physiological responses to different temperature and water regimes, as well using modelling techniques to determine their potential distribution pattens. He aims to determine what the key drivers of primary production in C4 grasses are and how this productivity may change under temperature and water stress. He asks the question, what are some of the main climatic determinants on C4 grass distribution and how may this change in future based on their physiological niches? He will be using Eddy covariance flux towers, ground-based vegetation indices and greenhouse experiments to address these questions.