Book excerpt: The Forest Carbon Partnership Facility (FCPF) of the World Bank has been supporting the Federal Government of Nigeria (FGN) to develop its REDD+ readiness mechanism and part of the funds were allocated to undertake a “low intensity” forest carbon inventory in Nigeria within the Technical Assistance (TA) Agreement (UTF/NIR/066/NIR) which was signed between the Government and the Food and Agriculture Organization of the United Nations (FAO). An inventory design was developed, including a field operations manual, and field training was carried out to build the capacity of technical forestry staff on field data collection, database development, and data analysis. The sampling design used was a stratified random cluster sampling, using the main ecological zones as strata. The sampling unit was a cluster composed of three square nested plots of 35 m x 35 m; placed in an L-shape arrangement at 100 m apart.