Biodiversity Conservation and Carbon Sequestration in Cocoa Agroforest in Southern Cameroon

Abstract

The study is conducted in semi deciduous rain forest zone of southern Cameroon to appreciate the impact of cocoa agroforest on plant biodiversity conservation and carbon sequestration. Twenty-four transects of 1.5 km long and 10 m wide were established in eight villages to evaluate the cover percentage of cocoa compare to other land use system (LUS). Forty five plots of 625 m² (25 m x 25 m) each were surveyed in these villages. In these plots, all the individuals with DBH (Diameter at the Breast Height) greater or equal to 4 cm were recorded. The destructive method was used to evaluate carbon sequestration in different LUS for herbaceous plants, small woody plants, litter and roots, while the allometric equation of Brown was used for all individuals with DBH ≥ 4 cm. Seven LUS were identified in the Yaounde region: 23 % of these were cultivated land, 36 % were fallows, 16 % were cocoa field and 5 % represented the secondary forest derived from the slash and burn practices. In the regions of Mbalmayo and Ebolowa, eight LUS were identified, of which six shared with the region of Yaounde and two different, the degraded forest and swampy forest. Species encountered in cocoa agroforest represent 33.78 % of the total flora of the area. Fruit trees were abundant in those villages which have access to market (Persea americana, Dacryodes edulis, Citrus spp), while in Ambam region, original forest species mostly timber species were encountered (Baillonella toxisperma, Guibourtia tessmannii, Terminalia superba, Milicia excels). This agroforest can accumulate about 251.14 t C/ha. Theobroma cacao hosted about 21.51 t C/ha. The root system of cover species stocks an important quantity of carbon.