Relationship between stand regime and population structure of Pseudocedrela kotschyi (Meliaceae) and Terminalia macroptera (Combretaceae) in the Biosphere Reserve of Pendjari (Benin, West Africa)

Abstract

One of the major reasons for reforestation failure using tropical species is misunderstanding of the neighbourhood relationship within tree populations. This study used the natural stand structures ofTerminalia macroptera and Pseudocedrela kotschyi, two socio-economically important species, to design enrichment planting. A comparative analysis of the population structure of P. kotschyi and T. macroptera in two regimes (pure and mixed) was performed. However, results indicated that young T. macroptera individuals were predominant in both stand regimes. In the same way, no significant difference was found between diameter size classes with respect to stand regime. Trees showed weak density and a random pattern with the nearest neighbour distances varying between 5.67 (pure) and 7.01 m (mixed). P. kotschyi young individuals were also found to be predominant irrespective of stand regime; yet, the diameter size class distributions revealed significant variations with respect to stand regime. Trees had a higher density and stronger clumped pattern in pure stand as compared to mixed stand. The nearest neighbour distances ranged from 2.97 (pure) to 4.87 m (mixed). Our findings highlighted the relevance of taking into account relationships between stand regime and tree population structure while designing artificial plantings. Key words: Savanna woodland, density, spatial distribution, diameter class structure.