Influence of Land Tenure on Agroforestry Parkland Phyto-Diversity and Stand Structure in Sudanian Zone of Burkina Faso, West Africa

Abstract

Savanna Zone of Burkina Faso is characterized by the increasing population growth due to human migration from the north and central regions of the country for cultivating agricultural land and pastures. This situation induced land-use changes, and social reorganization has led to new approaches to natural resources management. Tenure issues in natural resources management limit the adoption of agroforestry systems and effective land use scale. This paper describes the species composition, structure, and diversity of woody species on agroforestry parklands at Tiogo under two types of land tenures. Ecological and structural characteristics of vegetation patches were computed to characterize the species composition. A variety of diversity measures were calculated to determine the heterogeneity for each type of land tenure. A total of 49 woody species belonging to 19 families and 38 genera were identified, of which 44 and 48 species were recorded in non-landowners’ farms and landowners' farms, respectively. Leguminosae, Combretaceae and Anacardiaceae were the most abundant families. The dominant species in agroforestry parklands were Vitellaria paradoxa, Parkia biglobosa, Lannea microcarpa, Piliostigma reticulatum and Piliostigma thonningii. Analyses of variance of the entire woody vegetation of agroforestry parklands revealed no significant differences in terms of all computed indexes but showed that the landowners’ farms were the most diverse than non-landowners farms. The density of stems ≥5 cm dbh and the basal area were higher in landowner’s farms than in non-landowners farms. In both types of farms, the size class distributions of the vegetation produced a reverse J-shaped curve, supporting that agroforestry parkland in Tiogo is dominated by young individuals. The spatial distribution of the seedling was mainly clumped, reflecting the dominance of clonal propagation. Security of land and tree tenure is a necessary condition for any land-based investment (planting and protection of preferred species and soil amendment). The challenge to maintain parklands’ tree biodiversity in “good” condition also needs to consider the flexibility of land tenure and equitability sharing of the benefits from trees.