Sudanian versus Zambezian woodlands of Africa : composition, ecology, biogeography and use

Abstract

The Sudanian woodlands (SW) and Zambezian woodlands (ZW) of Africa cover two extensive vegetation zones in Africa. The main question is how similar or different are their woodlands. This paper aims to synthesize available information on woodlands of the Sudanian (SR) and Zambezian (ZR) regions in terms of: i) their floristics and ecology, ii) main drivers of change, iii) their socio-economic relevance to local populations, and iv) how resource use affects the main drivers.

This synthesis deals with 141 publications, including 94% research articles and books on Sudanian and Zambezian woodlands of Africa. Google Scholar's search engine were used. Inclusion criteria comprised the geographical focus (Sudanian and Zambezian regions), the ecosystem type (woodland), and the type of information reported in the studies (ecology, socio-economic and biogeography aspects). The overall results were categorized as addressing either ecological or socio-economic aspects of woodlands.

The SW and ZW share a number of families, genera and species. The ZR counts at least 8500 plant species, of which 54% are endemic, while there are possibly no more than 2750 plant species in the SR. Three distinct woodland types are ecologically important and clearly differentiated in the ZW. However, combined effect of the wide tolerances of the species and the gradual change in the climate in the SZ, makes it difficult to recognize distinct woodland systems. The presence of great rifts and swells in the Zambezian part of Africa, explain in part the difference in the vegetation composition and the high diversity and plant endemism in the Zambezian zones. In both Regions, use of woodland and the associated ecological impacts are quite similar.

Both biogeography and land use change explain the vegetation differences between the two regions. Knowledge of factors underlying vegetation adaptations and change provide a basis for sustainable resource use through integrated multiple-use systems.