Phytosociological analysis of woody plant species as determinant of above ground carbon stock in the Guinea Savanna Ecological Zone of Nigeria

Abstract

Estimation of the magnitude of forests as carbon sinks or sources require accurate and reliable estimate of biomass density of the forests. However, poor knowledge of the quantity of biomass per species in a given ecosystem is one most uncertain factor involved in estimating carbon stock in developing countries. The aim of this study is to examine the relative phytosociological importance of woody species in determining above ground biomass/carbon stock in the Guinea savanna ecological zone of Nigeria. The research methodology employed field survey inventory, biometric measurements and laboratory analysis. Measurement was carried out in 45 quadrat sampling plots of 500 m². Destructive biomass sampling was used for biomass estimation. The phytosociological analysis carried out in this study revealed that ecologically dominant tree species in the study area in decreasing order were Vitellaria paradoxa,(32.73) Irvingia gabonensis, (28.38) Parkia biglobosa, (23.20) Anogeissus leiocarpus, (21.64) and Pterocarpus erinaceous (15.73). Others include Detarium microcarpum (13.85) Prosopis Africana (13.69) Danellia oliveri (11.91) Afzelia Africana (10.80); together accounting for about 65.2 % of total species dominance. By contrast, tree species that contribute most to the above ground biomass stock in the study area were Anogeissus leiocarpus, (705.82 kg) Parkia biglobosa, (631.47 kg) Pterocarpus erinaceous, (522.23 kg) Irvingia gabonensis (469.72 kg) and Vitellaria paradoxa (381.80 kg). Finding in this study implies that Anogeissus leiocarpus is the tree species with highest potential to store carbon in the study area. The study recommends that the identified ecologically dominant tree species be well protected in order to exploit their carbon sequestration potential for mitigating climate change.

Keywords: Phytomass, Carbon, Climate Change, Mitigation, Sequestration