Structure and Natural Regeneration of Sterculia setigera Del. Plants Communities in Sudanian Zone of Togo (West Africa)

Abstract

Sterculia setigera is a multipurpose savanna tree with socio-economic importance due to its gum and cultural importance in sub-Saharan Africa. The present study was carried out in Togo’s Sudanian area to characterize the structure and regeneration potential of S. Setigera in order to define a sustainable management plan associated to its valorization as gum species. Data were collected during May and April 2010. The methodological approach was based on forest inventory oriented by the presence of S. Setigera. Total height and stem diameter at breast height (dbh) greater than 10 cm of all trees species were measured in 97 plots. In each plot, ecological parameters were recorded and the seedling and suckers (dbh<10cm) of S. Setigera were counted. Forty six woody species belonging to 42 genera and 22 families were listed. Fabaceae, Combretaceae, Malvaceae and Moraceae were the dominated families. The prominent species were S. Setigera, Balanites aegyptiaca, Lannea acida and Diospyros mespiliformis. Presence/absence data of the overall species recorded in each plot was subjected to multidimensional scaling and results showed 5 plants communities: fallows, croplands, low side savannas, mean side and tablelands savannas and uplands savannas. The structure adjusted by 3-parameter Weibull showed reverse “J” shape for class diameter distribution with shape parameter varies between 1 and 3.6 showing a predominance of individuals with small diameter within the overall study area. The height structure showed a bell-shape and left dissymmetric distribution. The regeneration rate is very low (5.21 to 16.15). It is necessary to define a sustainable program for the conservation and valorization of this gum species.