Savannah ecosystems play an important economic role at the agrosylvopastoral level. However, agriculture and pastoral activities constitute the main human pressures on these ecosystems. These activities are exacerbated by bushfires which are common in this sudano-sahelian zone of Cameroon. The objective of this study was to characterize the floristic diversity of the herbaceous vegetation in the Sudano-Sahelian zone of Cameroon. The aligned quadrat points method was used for the floristic surveys. The experimental design consisted of four treatments which were the Subdivisions and three repetitions which were three villages per treatment. In the savannah ecosystem of each village, an aligned quadrat point (50 m x 50 m) has been installed and along each 25 m half-diangonal, ie 100 aligned points, all the herbaceous plants were inventoried. The analysis of variances was used to test the levels of specific diversity of plant formations in villages and subdivisions. Records include 71 herbaceous species belonging to 66 genera and 21 families in our study area. Species with strong contributions to specific recoveries for all sites were Pennisetum pedicelatum, P. polystachion, Hyparrhenia rufa, H. hirta, Aristida adscensionis, A. hordeacea, Andropogon gayanus, Loudetia togoensis, Eragrostis cilianensis, E. tremula and Schoenefeldia gracilis. The most representative families of our study area were Poaceae, Fabaceae and Asteraceae. The Shannon diversity index varied from 4.2 to 5.78 bits, and the Pielou evenness index from 0.77 to 0.85. The study revealed a progressive evolution of the herbaceous vegetation with a very high proportion of species on the average. Within the framework of a sustainable management of natural resources, our results provide additional information on the floristic composition of the herbaceous vegetation in the sudano-sahelian zone of Cameroon.

Phytodiversity is a vital and capital element for survival of humanity. This study aims to characterize the floristic diversity and the structure of the woody vegetation of the Mayo-Danay division in the Sudano-Sahelian zone of Cameroon. The transect method was used for the floristic surveys. The experimental design consists of four (04) treatments which are the subdivisions and three (03) repetitions, or three (03) villages, per treatment. In the savannah ecosystem of each village, a transect (500 m x 20 m) was installed and along each transect, all woody trees with a dbh ≥ 10 cm at 1.30 m are inventoried, the diameter is measured as well as the height. The villages surveyed are as follows: Djelme, Gouma and Nouldaina in Gobo sub-division; Bangana, Kononaye and Tchalawa in Guere sub-division; Madalam, Sadamakou and Vagandja in kaïkaïsubdivision; Kalfoucenter, Bougaye and Ngalaï in Kalfou subdivision.The analysis of variance permitted to realize the comparison between the different sites and the Fisher's LSD test allowed to make the comparison between the averages, and all was performed by Statgraphic + 5.0 Software.The total specific richness is 57 species belonging to 43 genera and 26 families out of 36 surveys that were carried out in our study area. The spescific diversity in Mayo-Danay varied according to the sites: the Shannon diversity index varies from 2.93 bits in the Bangana site to 4.82 bits in the center of Kalfou; the Pielou Evenness values varied from 0.45 in the Bangana site to 0.67 in the Kalfou-center site; the density was 14.89 ± 3.27 stems/ha in the Bangana site to 55.44 ± 10.49 stems/ha in the central Kalfou site. The basal area varied between 23.01 ± 13.17 m 2 /ha in the Kononaye site and 109.64 ± 22.93 m 2 /ha in the Vagandja site. The evaluation of the horizontal structure in the shape of an inverted J, and of the vertical in the shape of a bell shows a predominance of young subjects and especially of average individuals. The study made it possible to assess the structural characteristic of the woody settlement of the Mayo-Danay division. It thus reveals a regressive evolution of the woody stand with a very high proportion of species of small circumference and medium height. As part of a sustainable and rational management of natural resources in the Sudano-Sahelian environment, this study provides additional information on the current state of the woody populations of Mayo-Danay division.