A bioeconomic analysis of the carbon sequestration potential of agroforestry systems: A case study of Grevillea robusta in South Western Uganda

Abstract

Grevillea robusta is an agroforestry tree species that has been widely promoted under the carbon forestry schemes in South Western Uganda. The objective of the study was to estimate the amount of carbon sequestered and the profitability of carbon offsets in G. robusta woodlot andagroforestry management options under the Plan Vivo system and small-scale Clean Development Mechanism (CDM). An allometric equation forG. robusta was used to calculate the carbon stocks and merchantable wood volume in the woodlot and agroforestry management options over different crediting periods. The results indicated that G. robusta woodlots and agroforestry management options sequestered 470 and 225 t CO₂ e ha-1 respectively, over a 20 year rotation. The net present values (NPVs) of the G. robusta agroforestry management option of US$4367 and 4447 ha^-1 under the Plan Vivo and small-scale CDM, respectively, were higher than US$1358 and 1902 ha^-1 in the G. robusta woodlot management option. The NPV of the traditional agroforestry system was US$ 3992 ha^-1. These results show that, whereas the woodlot option stores more carbon, it is the least profitable option. Analysis also revealed that, although poor households were well represented in the Plan Vivo scheme, they preferred the agroforestry option. This suggests that forest carbon offsets on productive agricultural land, should focus on promoting agroforestry technologies in order to increase profitability and targeting of the poor households.