Impact of Useful Species Preferences on Carbon Stocks and Annual Increments in Various Cocoa-based Agroforestry Systems in Central Region of Cameroon
Jules Christian Zekeng, Jean Louis Fobane, Hortense Elvire Biye, Cédric Djomo Chimi, Marguérite Marie Abada Mbolo
Abstract
This paper evaluates the potential effects of farmers’ species preferences on carbon stock in cocoa-based agroforestry systems (CAFS) in the Central Region of Cameroon. To achieve this goal, the species composition and structural variables of two land-use systems were investigated using 26 plots of 30 m × 30 m each, of which 20 were distributed in CAFS and 6 in adjacent secondary forests. Allometric models were used to estimate the species aboveground and root carbon stock. Ordination analysis indicated three types of species management systems: high-density timber and fruit trees; high-density Musaceae, palms and other shading trees; and low-density timber and fruit trees. The average densities of cocoa shading trees and shrubs were 234 ± 136 and 843 ± 360 individuals’ ha−1, respectively. Thus, the average potential carbon stock of the sampled CAFS was estimated at 186.97 ± 86.06 Mg C ha−1, 22% representing the root carbon stock. The transformation of secondary forest into various species management systems decreased the aboveground carbon by 18–34%. The annual rate of carbon accumulation estimated based on ring analyses was within the range 2.32–13.74 Mg C ha−1 year−1. The monetary value of the total carbon stored and the carbon accumulation rate were US$4042 ha−1and US$159 ha−1year−1, respectively.