The impact of land use on species composition and habitat structure in Sudanian savannas - A modelling study in protected areas and agricultural lands of southeastern Burkina Faso

Sudanian Savannas are under high agricultural pressure and are therefore changing rapidly. Due to high population densities and an increasing need for food and cash crops, the mosaic of traditional agroforestry systems, fallows and savanna is being transformed into intensively used croplands and savannas only remain in protected areas. The focus of this study is to characterize the differences in plant diversity and composition between protected areas and surrounding agricultural lands and to identify areas most important for plant conservation. Building on observation and collection records, we modelled distributions of individual plant species and summarized these. We mapped the species richness of vascular plants in general, of woody plants, graminoids and forbs, the share of weeds and the average size of grasses and trees and calculated means for the reserves and outside areas. Distinct differences between protected areas and agricultural lands have been found in the richness of herbs (both forbs and graminoids) and weeds as well as in the size of grasses : Woody species seem to be less affected by human impact in the agricultural lands concerning both species richness and plant size. Weeds are playing an important role in the higher species richness of the agricultural lands.