ANALYSIS OF THE HERBACEOUS UNDERGROWTH OF THE WOODY SAVANNA IN THE FATHALA RESERVE, DELTA DU SALOUM NATIONAL PARK (SENEGAL)

We investigated the herbaceous layer in the Fathala Reserve, a fenced area in the Delta du Saloum National Park in Senegal, in order to determine the role of the under-growth vegetation in woody savanna. We recorded 53 plant species from 19 families in 30 herb layer relevés of 5 × 5 m. Fabaceae (22%), Convolvulaceae (13%), and Poaceae (11%) were the most frequent families. On the basis of a Detrended Correspondence Analysis and a cluster analysis we distinguished 4 vegetation units in the herbaceous layer. Andropogon gayanus var. bisquamulatus, Schizachyrium sanguineum, and Andropogon gayanus (beardless, non-tufty type) were dominant in units 1, 3, and 4, respectively. Unit 2 was composed of the most ubiquitous species. In a Canonical Correspondence Analysis, habitat type (well-drained sites, moist depressions, and seasonally inundated sites) only explained 15.9% of the undergrowth vegetation variability. We concluded that only woody plants and dominant grasses represent the forming element of woodland savanna. Herbaceous plants recorded in the Fathala Reserve do not manifest any specific requirements to environmental, and particularly soil, conditions.