Impact of climate, land use and disturbances on the population structure in natural stands and regeneration patterns of Celtis toka in Burkina Faso, West Africa.

---

Résumé

Celtis toka is a multipurpose wild mystic tree of Burkina Faso with an unknown population dynamic stability. The study was conducted to assess the impact of climate, land use and disturbances on the natural population of the species. This study was carried out in two climatic zones and two land use types in Burkina Faso. Data on the structural traits and the disturbance characteristics were collected on each individual of C. toka. Linear models were used to evaluate the impacts of climate and land use on the structural characteristics of the species. The study recorded 290 plant species belonging to 105 families and 113 genera. The density of C. toka significantly varied across climatic zones and land use types for the adult stratum (p ≤ 0.05). Density of different individuals was high in the protected areas (102.33 ± 28.56 trees ha−1) and unprotected areas (160.31 ± 61.82 juveniles ha−1) in the Sudanian climatic zone than in the Sudano-Sahelian climatic zone, where it was lower in unprotected areas (11.94 ± 0.77 trees ha−1) and protected areas (0.31 ± 0.31 juveniles ha−1). Linear regression analysis showed a significant effect (p < 0.05) of climate, land use types, overgrazing, hollows, pruning, and debarking on the structural characteristics. The most significant tree species according to their ecology were Tamarindus indica (Importance Value Index (IVI): 61.38 %), Combretum micranthum (IVI: 38.4 %), and Balanites aegyptiaca (IVI: 33.09 %), all of which had high IVI values. Adult and juvenile strata displayed an unstable structure in most land use types. The regeneration rate of the species was 0.85 %. Urgent initiatives are required for the species and to raise awareness for protection in its natural habitat to promote its conservation and sustainable use.

Mots-clés

Conservation Critically endangered Density Diversity Unstable population