Modelling and mapping the topsoil organic carbon content for Tanzania

Soil organic carbon (SOC), held in soil organic matter, is a key indicator of soil health and plays an important
role in the global carbon cycle. The soil can act as a net source or sink of carbon depending on land use and
management. Deforestation and forest degradation lead to the release of vast amounts of carbon from the soil
in the form of greenhouse gasses, especially in tropical countries. Tanzania has a high deforestation rate: it is
estimated that the country loses 1.1% of its total forested area annually. During 2010-2013 Tanzania has been
a pilot country under the UN-REDD programme. This programme has supported Tanzania in its initial efforts
towards reducing greenhouse gas emission from forest degradation and deforestation and towards preserving soil
carbon stocks. Formulation and implementation of the national REDD strategy requires detailed information on
the five carbon pools among these the SOC pool. The spatial distribution of SOC contents and stocks was not
available for Tanzania. The initial aim of this research, was therefore to develop high-resolution maps of the SOC
content for the country.