Genetic diversity of Mansonia altissima A. Chev. under different regimes of human impact in the Akure Forest Reserve, Nigeria

Abstract

Mansonia altissima is an important West African timber tree species. For the purpose of examining the effect of human impact on its genetic diversity, genetic diversity and spatial genetic structure of the species under different regimes of human impact were investigated in the Akure Forest Reserve, Nigeria, using 504 amplified fragment length polymorphism (AFLP) markers. The results indicate a very low genetic diversity in M. altissima within the forest reserve (He = 0.045; PPL = 16.75%; Br = 1.162). The highest genetic diversity was observed in the primary forest (He = 0.062; PPL = 21.00%; Br = 1.204), with the lowest genetic diversity in the isolated forest patch (He = 0.032; PPL = 9.00%; Br = 1.089). A significant and pronounced spatial genetic structure was found in the logged forest and in the isolated forest patch. In contrast, the primary forest exhibited very weak spatial genetic structuring. As expected, no spatial genetic structure was found in the planted stands of M. altissima. From a conservation point of view, our results suggest that genetic diversity of M. altissima is at risk in the forest reserve. The scale of human impact in the study area could pose a serious threat to the maintenance of genetic diversity of the species. These results would offer practical applications in the conservation of other tropical tree species.