Synthesizing knowledge about tree diversity, density, and distribution in the savanna woodlands of Sudan

Abstract

• Comprehensive synthesis of tree density and diversity in Sudan’s savanna woodlands. • Identifies 163 species, with Acacia seyal and Balanites aegyptiaca as dominant species. • Reveals regional density and diversity patterns influenced by environment and human activity. Savanna ecosystems comprise a complex and diverse biome, marked by the balanced cohabitation of trees and shrubs alongside a rich assembly of herbaceous flora, particularly grasses. In Sudan, savanna ecosystems provide invaluable services that sustain the livelihoods of millions of people. Here, we synthesized the existing knowledge about tree density, diversity, and distribution in the savanna woodlands of Sudan to assess tree diversity, evaluate tree conservation status on the basis of tree abundance and distribution according to IUCN guidelines, and map tree diversity and density in savanna woodlands. The research process started with an extensive search for relevant literature across various databases. The data sources included Google Scholar and Web of Science, as well as reports and publications available in the libraries of Sudanese universities. The results revealed that savanna woodland contains 163 tree species belonging to 40 families. Fabaceae was the most frequent family, accounting for 44 species. The species richness among the sites ranged from 1 to 73 species, and the stand density ranged from 20.5 to 500 stems/ha. Moreover, this study revealed that Acacia seyal, Acacia senegal, Balanites aegyptiaca , and Ziziphus spina-christi are the most frequent species and that these four key species are well distributed throughout the savanna woodland of Sudan. While this first synthesis of tree diversity and distribution lacked data at the sample plot level, it should stimulate further research in this crucial ecosystem.