Objectives: The term 'biodiversity' is often misinterpreted as the number of species per area. Actually, biodiversity covers not only species numbers but also the diversity of ecological structures, e.g. spatio-temporal structures such as dynamic landscapes. These levels of biodiversity (i.e. species diversity and structural diversity) often are closely linked. For example, empirical investigations have shown that in arid and semi-arid savannahs species diversity is strongly influenced by the structural diversity (landscape structures at different scales), which in these systems is characteristically formed by the woody vegetation. This 'vegetation shaped' structural diversity is highly dynamic and depends to a large extent on climatic conditions (key word 'climatic change') and on anthropogenic land use (key words 'shrub encroachment', erosion, grazing management). Based on the example of the semi-arid savannah system of the southern Kalahari we shall explore the interrelations between structural and species diversity under dynamic conditions using an interdisciplinary approach (zoological, botanical, genetic and socio-economic investigations, remote sensing and spatially-explicit modelling). The aim of this project is to evaluate the impact of current and realistic future land use intensities and practices on the survival of selected animal and plant species and thus species diversity under realistic scenarios of climatic change. By these means we shall quantify risks of short and long-term losses of biodiversity and develop management support for sustainable land use in these fragile systems. The results and the simulation models developed in this study will be transformed into user-friendly educational and management tools for nature conservationists, ecologists and land users in southern Africa.
Investigations: We will empirically explore the population dynamics, genetic structure and survival of selected animal and plant species in relation to the structural diversity (vegetation based landscape structures at relevant scales) of the system. These investigations will improve the existing knowledge base and supplement relevant but missing information. The structural diversity will be mapped at different scales (remote sensing and field mapping) and geostatistical methods will be used for its quantification. Additionally an existing spatial vegetation model describing the vegetation dynamics in the southern Kalahari will be used to simulate the long term dynamics of the structural diversity under scenarios of climatic change and different intensities and types of land use. Based on the existing data and the empirical studies described above we will develop new population models that will improve our understanding of the population development and the extinction risk of the selected species in dependence on the given structural diversity. These population models will be linked with the existing spatial vegetation model to allow for investigations of the population dynamics of the selected species under variable, dynamic conditions of climatic change and realistic future land use scenarios. These scenarios of future land use will be based on socio-economic and ethnological investigations. The linkage of scenarios of natural and anthropogenic changes with their consequences for selected indicator species will, for the first time, allow us to make predictions of biodiversity changes within a system dependent on regional and global change.
German Partners: (1) Prof. Dr. P. Poschlod (Nature conservation II, University of Marburg); (2) Prof. Dr. A. Rasa (Zoology, University of Bonn); (3) Dr. K.-H. Mueller (Geography, University of Marburg); (4) Dr. R. Brandl, Community Ecology, UFZ-Centre for Environmental Research Leipzig-Halle; (5) Dr. M. Bollig (Ethnology, University of Cologne)
South African Partners: (1) Prof. Dr. S.J. Milton (Nature Conservation, University of Stellenbosch); (2) Dr. W.R.J. Dean (FitzPatrick Institute for Ornithology, University of Cape Town); (3) Prof. Dr. N. van Rooyen (Botany, University of Pretoria)