Species Distribution and Patterns in a Forest-savannah Ecotone: Environmental Change and Conservation Concerns

Abstract

Understanding the dynamics and patterns of biodiversity in transition forests is vital in promoting conservation and addressing environmental change issues. This work focused on elucidating the diversity, structure, and carbon potentials of a forest-savannah ecosystem. To achieve this, 8 forest plots that measured 50 m × 50 m each was set up in a forest-savannah landscape and used to identify and measure tree species ≥ 10 cm diameter at breast height (DBH measured at 130 cm). Species importance value was used to summarize the biodiversity patterns and the aboveground carbon estimates were elicited with the allometric equation. 43 species within 22 families were enumerated and the diversity was generally low (ranging from 1.82-2.5). Species such as Daniellia oliveri (Rolfe) Hutch. & Dalziel, Pyrostria guinnensis Comm. ex A. Juss, Dialium guineense Willd. and Margariteria discoidea (Baill.) G.L Webster were the dominant species, and had the highest importance values of 113.06, 55.13, 28.16 and 16.95, respectively, while Allophlus africanus P. Beauv., Annona senegalensis Pers., Anthonatha macrophylla P. Beauv., Ficus capensis Thumb. and Lecaniodiscus cupanioides Planch had the least importance values of 0.16 each. Carbon estimates ranged from 16.43172-42.9298 t/Ha. Most frequent species with higher basal areas no doubt contributed much to the carbon estimates, but did not have higher capacities in storing carbon. Managing the ecosystem with more carbon-dense species was seen as a suitable strategy for addressing environmental change in the ecosystem and region.