Heliyon (Jan 2024)
Plant communities on inselbergs in Burkina Faso
Abstract
The safeguarding and sustainable management of natural resources, particularly plant resources, requires the implementation of conservation strategies. The study of plant communities is an essential tool for monitoring the development of plant formations. The aim of this study was to identify the plant communities on inselbergs of Burkina Faso in West Africa, to provide a database to supporting the sustainable management of the plant resources withing these fragile ecosystems. Stratified and random sampling was carried out on selected inselbergs in different parts of Burkina Faso along a climatic gradient. In the different phytogeographical sectors, inselbergs consist of granite or sandstone. Plant surveys were conducted using 900 m2 plots for the woody stratum and 100 m2 plots for the herbaceous stratum. An exhaustive list of plant species was compiled and an abundance-dominance coefficient for each species was determined. A DCA, through PCord.6, was used to obtain preliminary groups. Indicator species were determined by a Monte Carlo test with p < 0.05 and calculation of the fidelity index (Phi). Diversity indices through the Shannon index and equitability of Pielou were calculated using Pcord.6 to compare plant communities. A total of 12 plant communities were identified for the inselbergs of Burkina Faso, including 9 communities for savannah and 3 communities for monocotyledonous-mats and ephemeral flush vegetation. The main ecological factors governing the distribution of these inselberg plant communities were found to be were found to be climate, soil depth, soil moisture and altitude. In savannah plant communities, the Terminalia laxiflora and Tephrosia nana communities (unit 6) had the highest number (13) of diagnostic species and the highest fidelity (Phi = 0.97) was for Cleome viscosa species in the Acacia tortilis and Aristida kerstingii communities (unit 1). Diagnostic species numbers vary from 6 to 4 in monocotyledonous-mats and ephemeral flush vegetation and the Dopatrium longidens (Phi = 0.76) and Cyperus podocarpus (Phi = 0.75) have the highest fidelity to unit 3. The Shannon diversity index of deep soil plant communities was highest and significantly different from that of the other savannah communities. Concerning the Piélou equitability index, high values were found in all plant groups, reflecting the absence of species dominance and a balance of the different plant groups.Floristically, Afrotrilepis pilosa infestation of inselbergs is common in West Africa. In Burkina Faso, in addition to Afrotrilepis pilosa, 10 other plant species are found specifically on inselbergs. Given the fragility of the ecosystems in which they live, these inselberg species should be protected.
