Current PhD Students

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Nozuko Ngqiyaza

np.ngqiyaza@gmail.com

Room number 115, 2nd Floor, Botany

Functional traits of thicket pioneer species that invade grass-dominated savannas.

Short description of thesis: My research project is looking at the ecology of broadleaf thicket pioneers that recruit into savannas and grasslands. The research focuses on functional traits of (1) savanna species that establish and mature within the open grassy matrix, (2) thicket pioneers species that establish under medium to large-sized savanna trees and initiate clump formation, and (3) “obligate” forest or thicket species that are associated with closed-canopy vegetation where this occurs as an endpoint of the successional sequence. The research also entails phylogenetic analyses to examine the evolutionary history of thicket pioneers and their life history strategies.

The study aims to compare the traits between savanna, thicket pioneers and obligate closed-canopy species and to determine how the traits characterizing the three ecological successional stages compare across an aridity gradient, and whether there are commonalities in the trait differences between the three groups across the aridity gradient.

Supervisor: Prof. Susanne Vetter


 PhD Student

Bridgette McMillan (BSc PhD, RU)
g24m2993@campus.ru.ac.za
Room 115, 2nd floor

Flames of the Savanna: Exploring the Role of Grasses in Shaping Fire Dynamics of the Kalahari

My PhD investigates how fire, grass functional traits, herbivory, and climate influence grass species composition and recovery in semi-arid Kalahari savannas. I combine field experiments on tussock flammability, and vegetation monitoring across fire scars, with statistical modelling to track the post-fire responses of grasses over time. I also explore how climate change may shift grass distributions and fire regimes, with broader implications for ecosystem functionality in arid landscapes.

Supervisor: Prof.  Susanne Vetter, Rhodes University
Co-supervisor: Prof. Michelle Greve, University of Pretoria

Publications:
Singini, E.J., Mc Millan, B., Newete, S.W. and Witkowski, E.T.F. (2024) Ecological drivers of Seriphium plumosum encroachment: Implications for management and conservation. South African Journal of Botany. 176 (2025). p.1-8. 
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Liam Macleod Reynolds
Room 001, 1st floor
Thesis Title: Plant history pre-fire is a key determinant in the fire response
Short description of thesis: My thesis explores how plant life history (such as water availability and CO2 concentration) influences survival and recovery from fire-induced stress in common savanna saplings. Data from burning experiments will be used to generate models that predict mortality rates across a landscape under potential future climates based on fire intensity, mean annual precipitation, and CO2 concentration. The accuracy of this model will be ground tested at Kruger National Park in collaboration with a larger, internationally funded project investigating the relationship between drought and fire in causing large tree mortality.
Supervisor: Dr. Tiffany Pillay, Prof. Adam West, & Prof. Brad Ripley

Last Modified: Fri, 27 Jun 2025 16:12:36 SAST