My research focuses on savanna ecology and management, with a particular emphasis on understanding how climate change, including drought, elevated CO₂, and altered nutrient regimes, affects the dynamics of both native vegetation as well as the spread of invasive tree species. My PhD examined the drivers and biogeochemical impacts of woody plant encroachment across a rainfall gradient in South Africa. My current work investigates how environmental change influences vegetation structure, disturbance regimes and species interactions, integrating spatial analysis, experimental ecology, and biogeochemistry. Recent publications highlighted below;

• Nell, R., Pillay, T. and Vetter, S., 2024. Reconstructing thicket clump formation using association rules analysis. Journal of Vegetation Science, 35(3), p.e13265.
• Pillay, T., Ngcobo, S. and Ward, D., 2023. Nutrient addition, fire and grass competition affects biological nitrogen fixation in Vachellia sieberiana, and associated soil respiration. Pedobiologia, 96, p.150848.
• Pillay, T., & Ward, D. 2022. Experimental drought suppresses grass productivity and passive warming promotes tree sapling performance: Insights from African savanna species. Acta Oecologica, 114, 103813.
• Ward, D., Pillay, T., Mbongwa, S. and Kirkman, K., 2022. Spatial analysis reveals facilitation in young clonal trees and competition in older trees during re-invasion of encroaching trees in an African savanna. Plant Ecology, pp.1-14.
• Pillay, T., Ward, D.2021. Grass competition is more important than fire for suppressing encroachment of Acacia sieberiana seedlings. Plant Ecology 222, 149–158.
• Ward, D., Pillay, T., Mbongwa, S., Kirkman, K., Hansen, E., & Van Achterbergh, M. (2022). Reinvasion of native invasive trees after a tree-thinning experiment in an African savanna. Rangeland Ecology & Management, 81, 69-77.
• Pillay, T., Ward, D., Mureva, A., & Cramer, M. 2021. Differential effects of nutrient addition and woody plant encroachment on grassland soil, litter and plant dynamics across a precipitation gradient. Pedobiologia, 85, 150726.

Last Modified: Fri, 27 Jun 2025 16:13:40 SAST