Quantifying aboveground biomass in African environments : A review of the trade-offs between sensor estimation accuracy and costs

Increased global recognition of the role of forests in regulating the biosphereatmospheric carbon cycle through carbon sequestration, has resulted in a wide range of scientific studies on estimation, mapping, monitoring and the prediction of Aboveground Biomass (AGB) on various scales in sub-Saharan Africa. In many parts of the developing world, specifically in sub-Saharan Africa, the accurate quantification of AGB, although still a challenge, is important for national carbon accounting, REDD+ project payments, sustainable forest management and strategic policy-making. In this review, an overview of remote sensing applications in AGB estimation in sub-Saharan Africa, including research challenges and basic information related to the trade-offs between sensor estimation accuracy and costs, is provided. It is assumed that this review is timely, due to a relative increase in the number of remotely sensed forests carbon studies in the recent years (specifically the period between 1998 and 2013). Remotely sensed data is particularly appealing, due to its robustness, instantaneity and repeated spatio-temporal coverage and hence the ability to successful estimate and map AGB. However, estimation accuracy and image acquisition cost vary with sensor resolution and type. It is assumed that this study will provide guidance in future national carbon accounting studies, which is one of the main objectives of the Kyoto Protocol and the REDD+ (Reducing Emissions from Deforestation and Forest Degradation) project, housed under the United Nations Framework Convention on Climate Change (UNFCCC), particularly for the developing world.