The Spatial and Temporal Scale of Vegetation Change in Kruger National Park

Savanna ecosystems are highly dynamic. Their vegetation structure can change dramatically, for example because of the influence of fire or changing herbivore populations.(e.g. Buechner and Dawkins, 1961, Dublin, 1991, Pellew, 1983, Ruess and Halter, 1990, Vesey-FitzGerald, 1973). This presents dilemmas for habitat managers, who must decide on appropriate management strategies for National Parks and other savanna areas. Often, long-term data on vegetation change is lacking, and managers must interpret current habitat change without the benefit of knowledge about the natural variability and resilience of ecosystems. Palaeoecology has the potential to supply such data, providing a spatial, temporal and quantitative context for the interpretation of ecological change taking place today.

In this project, we aimed to address the following questions:
How variable is the vegetation of the Kruger National Park?
What is the nature of the variability (species composition, relative abundance, structure?)
On what spatial and temporal scales does the variability occur?
Can satellite data be used to calibrate the pollen record?
What is the role of fire in vegetation change?
What is the relationship between Nitrogen cycling and vegetation change?
What are the implications of vegetation change for habitat management?

These objectives relate to KNP Terrestrial Ecosystem Research aims, in that the results will contribute to the understanding of ecosystem dynamics, at a range of temporal and spatial scales. The work on charcoal abundance may help to elucidate past fire regimes in the area, and thus provide useful information for the Fire research group. This project could also work in collaboration with Herbivory Research and the Integrated Plant-Animal facet, providing long-term data on vegetation change, which could potentially be correlated with the abundance of herbivores, particularly elephants. The outcome of the project as a whole will be relevant to KNP Management Orientated research aims, in that the data may be used as a basis for Thresholds of Potential Concern (TPCs).