BOREAL FOREST
The boreal forest biome holds the second largest stock of carbon; most of this is stored in the
soil and litter. The draining of boreal forest peatlands, inappropriate forestry practices and poor
fire management may all cause significant losses of the carbon stored in this ecosystem.
Boreal forests occupy large areas of the northern hemisphere recent studies suggest that these old-growth forests may indeed
and are mainly found in Canada, Russia, Alaska and Scandina- be carbon sinks (Luyssaert et al. 2008). In general, due to the low
via. Biodiversity in these forests is generally low. Plant biomass is decomposition rates and the extensive peatlands they can grow
much higher than in the tundra, with roughly 60–100 tonnes of on, boreal forests are considered to be important carbon sinks.
carbon per hectare, of which around 80% is in the above-ground
biomass (Mahli et al. 1999; Luyssaert et al. 2007). Because of the HUMAN IMPACTS AND IMPLICATIONS FOR
low temperatures, decomposition in boreal forests is slow. This CARBON MANAGEMENT
leads, as in the tundra, to large accumulations of carbon in the Increasing human pressure on these forests, through logging
soil pool (116–343 t C per ha, Mahli et al., 1999; Amundson 2001). and mining, and the draining of the peatlands these forests
Fire is common in boreal forests and is one of the main drivers grow on, releases carbon to the atmosphere and significantly
of the carbon balance here, with carbon being lost from the sys- reduces their carbon storage capacity. Protection of boreal for-
tem when fire frequencies are high (Bond-Lamberty et al. 2007). ests against logging and implementing best forestry practices
There is debate about whether the very mature old-growth boreal may therefore reduce carbon emissions, sustain carbon stocks,
forests are currently a carbon source or a carbon sink, though and maintain uptake by these forests.
Tundra
Boreal forest
Temperate forest
Temperate grasslands, savannas and shrublands
Desert and dry shrublands
Tropical and subtropical grasslands, savannas and shrublands
Tropical and subtropical forests
Source: adapted from Olson et al., 2001.
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