Jason Donaldson

Research and background

I am an invasion ecologist and in a general sense, my interest is in landscape patterns and what processes drive the transition of one system to another. To date, I have investigated the relationship between trees and grasses in savanna systems and the influence of low nutrient soils on indigenous trees. In addition to this, I have a strong interest in the philosophy of conservation and the role that humans play in a natural world from which we have become remarkably separated. The study of invasion ecology provides large scale natural experiments with a multitude of questions that are interesting from both the perspective of a biologist and conservationist. My current research attempts to address these interests and is focused on the barriers to invasion that are either negated or intensified as a result of human aided introduction and the pathway associated with the relevant introduction.


Humans have been significantly manipulating the distribution of many plant species for at least the past 500 years (Mack 2003). Human-mediated movement of plants was initially associated with the need for resource security in newly colonized areas (Mack 2003). However, over the past century the rise of global trade and long distance transportation has resulted in a continuous increase human-mediated dispersal. The result is a global spike in both the number of exotic species introduced and the number of individuals deliberately introduced. Currently, there are a large number of invasive Acacia species (native to Australasia) that invade a wide range of habitats in South Africa. Acacia were deliberately introduced to South Africa for three main purposes- commercial forestry, dune stabilisation and horticulture. The different human uses of an introduced species can have a profound effect on their ability to establish and become invasive due to differences in the number of plants planted, number of times a species is re-introduced, the proximity to suitable environments for growth, and cultivation effort.

Acacia elata

Acacia elata

The majority of literature to date has focused on the commercially important forestry and dune stabilising invasive Acacia species. My work looks specifically at the ornamental species Acacia elata (Fig 1) with work to date focusing on its reproductive biology in South Africa.The next phase of my research will utilize scale area curves at different spatial resolutions to assess the influence of Acacia elatas introduction history in shaping its current invasive distribution. Apart from this species specific study, I have recently finished work utilizing two different modelling techniques on the influence that method of introduction has had on the invasive distributions of eleven Acacia species currently considered invasive in South Africa. The ultimate intention of my work is to develop a comprehensive management plan for Acacia elata and provide an improved understanding of how introduction events can and do shape plant invasions.


I completed my undergraduate studies (B. Sc in Botany and Zoology) at the University of Cape Town in South Africa, followed by a graduate degree (B. Sc honours in Botany and Ecology) at the same institution. I am currently in my second year of my MSc at Stellenbosch University. My supervisors are Prof. Dave Richardson and Dr John Wilson.