Carbon, biodiversity & ecosystem services:
exploring co-benefits

Carbon storage in ecosystems

Ecosystems store carbon (C) in their biomass, both above ground and in roots, and in the organic fraction of their soils. The density of the carbon in ecosystems varies with vegetation and soil types. For example, carbon density is particularly high in tropical peat swamp, where dense vegetation and tall trees make up a large amount of woody biomass and the soils have very high carbon contents.

The map below shows the world subdivided into seven broad biomes and gives an estimate for the total amount of terrestrial carbon (biomass + soil) stored in each. The largest amount of carbon, about 548 Gigatonnes of C (Gt C), is stored in the world's tropical and subtropical forests, followed by boreal forest with 384 Gt C. In total, terrestrial ecosystems are believed to store about 2100 Gt C. The amount of carbon stored in soils is several times the amount stored in biomass.

The conversion, degradation or unsustainable management of ecosystems leads to the release of carbon to the atmosphere, e.g. peatland degradation contributes up to 0.8 Gt C per year to the total anthropogenic carbon emissions. The management of ecosystems for carbon is therefore now widely considered to be a key climate change mitigation measure.

Carbon Stored By Biome

Key literature: The Natural Fix? The Role of Ecosystems in Climate Mitigation.

Source: Carbon stored by biome. (2009). In UNEP/GRID-Arendal Maps and Graphics Library. Retrieved 15:45, January 25, 2010 from http://maps.grida.no/go/graphic/carbon-stored-by-biome. (Cartographer Riccardo Pravettoni), published in Trumper, K., Bertzky, M., Dickson, B., van der Heijden, G., Jenkins, M., Manning, P. June 2009. The Natural Fix? The role of ecosystems in climate mitigation. A UNEP rapid response assessment. United Nations Environment Programme, UNEP-WCMC, Cambridge, UK.