Elaboration of allometric equations for the Congo Basin forests


The REDD+ mechanism calls for the preliminary construction of a system for measuring and monitoring forest carbon stocks. Several tools are needed to this end, including “allometric equations”.  The purpose of these biology-based equations is to use samples to assess a forest´s biomass by considering parameters which are easy to measure, such as the diameter, the height and the wood density of trees in a forest.

Within this framework, ONFI and its partners TEREA and Nature+, was asked by the Central African Forests Commission (COMIFAC) in 2013 to contribute to the “regional REDD+ project” (PREREDD+), which was launched in 2011.

The challenge? Helping the countries in the Congo Basin to establish allometric equations.


ONFI contributions

Actions carried out by ONFI and its partners:

  • Performance of forest-type stratification of the Congo basin;
  • Designing a regional methodology of data collection;
  • Surveying forest owners to pre-identify potential collection sites;
  • Training national research institutions and REDD National Coordination bodies on the elaboration of allometric equations, data collection and analysis.


Results and impacts

Six research institutions in six different countries (Cameroon, the Republic of Congo, Gabon, Equatorial Guinea, the Central African Republic and the Democratic Republic of Congo) have been trusted with the implementation of the collection methodology. They will be provided assistance for data collection, processing and effective use of data collected in the field.

The collection of data was achieved in October 2017, while the production of allometric equations was achieved in 2018.

Having these equations at their disposal makes it easier for the six beneficiary countries to determine the quantity of carbon stocks in their forests, and to progress towards the implementation of their national REDD+ strategies.


Some key data

Country: Cameroun, République du Congo, Gabon, Guinée-équatoriale, République centrafricaine et République démocratique du Congo

Topics: Climat, Gestion forestière

10/2013 – 02/2018

Budget : 2,3 millions €

Partners: Nature+, TEREA

Customer: Central African Forests Commission (COMIFAC)

Sponsor: World Bank, Global Environment Facility (FEM / GEF)


For further information

Site du projet PREREDD
Extrait du rapport d’activité 2016 de l’ONF