A core member of the DST-NRF Centre of Excellence for Invasion Biology (CIB), Dr Llewellyn Foxcroft, was one of ten recipients of the 2010 Man and Biosphere Programme Young Scientist Awards, which are endorsed by UNESCO. He received the award for a project focussing on the dispersal patterns of invasive alien plants along the Sabie River catchment.
Dr Llewellyn Foxcroft is currently based in the Kruger National Park (KNP) where he holds the position of scientist/ecologist. He is responsible for the Invasion Ecology research and monitoring programme in South African National Parks (SANParks). His main research interests are in alien plant invasions, investigating the processes and patterns of invasion, and the links to management interventions.
He is the editor of the journal Koedoe: African Protected Area Conservation and Science. Every year since 1989, the Man and Biosphere Programme has awarded grants up to R 38 000 (US$5,000) to ten young scientists. The laureates for the 2010 Young Scientist awards were announced at a meeting held in Paris from 31 May to 4 June 2010.
The main aim of Dr Foxcroft’s project is to determine the dispersal patterns of invasive alien plants along river corridors, from which suggestions for management may be made. The Sabie River catchment covers an area of about 7096 km2 and contains a large number of different land uses and alien plant control programmes.
The headwaters of the catchment are approximately 120km from the KNP, from where the Sabie River flows through the park and into Mozambique, therefore providing a perfect study site. Lantana camara, a globally problematic invasive plant, is widespread in the upper reaches and across the catchment, and thus was well suited as the focal species.
Using this study the investigators aim to test the assumption that the highly invaded areas in the headwaters of the watershed serve as source areas for these invasions. It is assumed that propagules move downstream during normal flow, but especially during large flood events. Management guidelines generally recommend control programmes to start at the upper watershed areas, working downstream.
However, as logical as the assumption is, the areas of some watersheds are immense, making complete control from top to bottom unlikely. The project will make use of genetic analysis techniques from populations of Lantana collected from across the Sabie catchment.
From the genetic analysis we will be able to determine which populations are related to each other, and thus likely source sites. However, we will also be able to determine which Lantana populations are not related to any other sites within the catchment, and will thus have been the result of introductions from sources outside of the catchment.
These results will show whether the assumption that the populations in the upper reaches of the catchment are in fact responsible for the invasion patterns in the rest of the catchment.