Évaluation du stock de carbone et de la productivité en bois d'un parc à karités du Nord-Cameroun

In the sudanian zones of northern Cameroon, the steady influx of migrants is causing much land clearance in large swathes of savannah lands. Creating denser stands of relict tree populations would be of value at once for agronomic, economic and environmental reasons. A method for evaluating the carbon stored in aerial biomass is proposed here for a village area of shea trees (Vitellaria paradoxa). The aim is to introduce agroforestry projects that will be eligible for the Clean Development Mechanism (CDM) as from 2012. In addition, an evaluation of fuelwood productivity in the area, using pollarding methods, was conducted for about thirty trees over a three-year period. A series of allometric equations was developed (for six shea specimens and one specimen each of Anogeissus leiocarpus and Combretum nigricans), establishing a ratio between aerial biomass and the diameter of the trunk (at chest height or at the branch base) or the surface area of the crown. This provided an estimation of carbon stocks per tree, and then per plot. Given the human pressure exerted on the tree zone, it was established that an 8-year rotation between pollarding operations would offer a healthy trade-off between the various interests involved. These studies offer a preliminary approach that will need to be consolidated with hindsight. Keywords: Vitellaria paradoxa, Clean Development Mechanism (CDM), pollarding, fuelwood productivity, carbon, agroforestry, sudanian zone, Cameroon