Research and Background
Despite the vast global impacts of invasive alien species, most introduced species fail to naturalize and/or spread when they are introduced into a new environment. Why some species succeed in becoming invasive, or are more invasive than other species, remains a central research question. Molecular ecological approaches can be used to identify genetic patterns that allow invaders to succeed in a new environment and potentially provide insight into effective management.
Broadly, my research interest is the molecular ecology of invasive plants. I am specifically interested in the interaction between invasive plants, their environment, and their human use that shape biogeographic and phylogenetic patterns in the introduced range.
PhD
My PhD research falls within the scope of a bigger “Molecular Ecology” project at the Centre for Invasion Biology that focuses on the fourteen major invasive Acacia species threatening water resources and native flora in the Cape Floristic Region in South Africa. These fourteen species are also found in several other regions around the world (Fig. 1).
Figure 1 Global distribution of nine major Acacia species (A. baileyana, A. cyclops, A. dealbata, A. decurrens, A. longifolia, A. mearnsii, A. melanoxylon, A. pycnantha and A. saligna) classified as major invaders in South Africa (Nel et al., 2004) based on records from the Global Biodiversity Information Facility (GBIF, 2010, http://www.gbif.org).
Figure 2 Acacia saligna
Figure 3 Paraserianthes lophantha
Australian acacias are a widely distributed group of woody invaders of economic importance. Currently, there are a large number of invasive acacia species (native to Australasia) that invade a wide range of habitats in South Africa. I am working on two woody invaders, Acacia saligna (Fig. 2), and Paraserianthes lophantha (Fig. 3, invasive legume in a genus closely related to Acacia). The areas each species invades, their environmental impact, and introduction histories differ substantially. This provides the opportunity to test several mechanisms believed to promote invasive success, such as the similarity between the native and introduced niche; or hybridisation that gives rise to fitter genotypes in the introduced range; or high propagule pressure due to multiple introductions. My Phd aims to use population genetics, sequence variation, and ecological niche modelling to provide insight into the global invasion dynamics of these two species.
Academics
I completed my undergraduate studies (B. Sc in Botany and Zoology with financial orientation) at the University of Johannesburg in South Africa, followed by a graduate degree (B. Sc honours in Botany and Plant Biotechnology) at the same institute. I am currently in my third year of my PhD at Stellenbosch University. My supervisors are Prof. Dave Richardson, Prof. Dirk Bellstedt, Dr Jaco Le Roux and Dr John Wilson.
Collaborators
- Margaret Byrne and Melissa Millar on the genetics of A. saligna (Department of Environment and Conservation, Western Australia).
- Mark Robertson (Centre For Invasion Biology, University of Pretoria) and Bruce Webber (CSIRO, Western Australia) on the species distribution modelling of the subspecies of A. saligna.
Publications
- Thompson, G.D., Bellstedt, D.U., Byrne, M., Millar, M.A., Richardson, D.M., Wilson, J.R.U. & Le Roux, J.J. (accepted) Cultivation shapes genetic novelty in a globally important invader. Molecular Ecology.
- Thompson, G.D., Robertson, M.P., Webber, B.L., Richardson, D.M., Le Roux, J.J. and Wilson, J.R.U. (2011) Predicting the sub-specific identity of invasive species using distribution models: Acacia saligna as an example. Diversity and Distributions, 17, 1001-1014
- Le Roux J.J., Brown G., Byrne M., Ndlovu, J., Richardson, D.M., Thompson, G.D. and Wilson, J.R.U. (2011) Phylogeographic consequences of different introduction histories of invasive Australian Acacia species and Paraserianthes lophantha (Fabaceae) in South Africa. Diversity and Distributions, 17, 861-871.
- Thompson, G.D., Le Roux, J.J., Bellstedt, D.U., Richardson, D.M. & Wilson, J.R.U. (2011). Molecular research as tool for managing biological invasions: Acacia saligna as a case study. In: Proceedings of the 2nd International Workshop on Invasive Plants in Mediterranean Type Regions of the World. 2-6 August 2010 (Ed. Brunel S). pp. 107-117. Council of Europe Publishing, Mèze, France.
- Thompson, G.D., Le Roux, J.J., Millar, M.A., Wilson, J.R., Richardson, D.M. and Byrne, M. (2009) The Port Jackson 5. South African Journal of Botany 75, 441-442.
- Vardien, W., Richardson, D.M., Thompson, G.D., Foxcroft, L.C., Wilson, J.R.U., Le Roux, J.J. (submitted). The introduction history, spread, and current distribution of Lantana camara in South Africa. South African Journal of Botany.
- Thompson, G.D., Le Roux, J.J., Richardson, D.M., Wilson, J.R.U. (In preparation). Global phylogeography of a major invader: Acacia saligna.
- Thompson, G.D., Le Roux, J.J., Wilson, J.R.U., Richardson, D.M. (In preparation). Population genetics and phylogeography of the invasive legume, Paraserianthes lophantha.
- Thompson, G.D., Ndlovu, J., Le Roux, J.J., Wilson, J.R.U., Richardson, D.M. (In preparation). Cross-species amplification of nuclear and cytoplasmic microsatellite loci reveal patterns of genetic diversity for 11 invasive acacias in South Africa.
