Contribution of a forest rehabilitated with various schemes of agroforestry in storing carbon

Abstract

Rehabilitation of degraded forest areas in the Forest Research and Education (FRE) Wanagama 1 was conducted by planting trees and crops in various agroforestry schemes. This approach is aimed to establish a successful plantation while allowing local people gaining benefits through farming in the forest land. At present, the FRE Wanagama 1 has several forests stands with various ground cover vegetations. This research was carried out to estimate the contribution of the forest for storing carbon, by estimating aboveground biomass (stand, ground cover, and litter) as well as soil organic carbon. Results of this study reveal that from the above-ground perspective, Swietenia stand stores the greatest carbon, approximately (229.35 Mg.ha−1), followed by those of Eucalyptus stand (135.91 Mg.ha−1), Acacia stand (69.01 Mg.ha−1), and Gliricidia stand (59.35 Mg.ha−1). The lowest level of carbon storage is observed in Melaleuca stand (5.36 Mg.ha−1) due to annual harvest of the leaves for oil production. The highest soil organic carbon was found in Swietenia stand (135.10 Mg.ha−1), followed by those of Gliricidia stand (131.26 Mg.ha−1), Eucalyptus stand (107.53 Mg.ha−1), and Acacia stand (105.61 Mg.ha−1). Whereas the lowest soil organic carbon was found in Melaleuca stand (67.59 Mg.ha−1). Up to 61.78% and 92.04% of the total carbon in each stand and soil can be used to store carbon, respectively. However, the agroforestry scheme must be wisely chosen, otherwise they will be significat reduction in the capability of the stand and the soil in storing carbon.