Old growth temperate forests are an important global carbon sink, soaking up CO2 at much higher rates than previously thought.The dogma for many decades has been that once forests become mature, they have such a large volume of non-green respiring (and CO2 releasing) tissue that they do not accumulate carbon.As a result, old growth forests have been left out of discussions of carbon storage and sequestration.
Sebastiaan Luyssaert of the University of Antwerp, Belgium and his colleagues have shown that in forests from 15 to 800 years old, the net carbon balance, including soils, is positive. That means that forests accumulate carbon regardless of age.
Luyssaert found that boreal and temperate forests of the northern hemisphere sequester about 1.3 gigatonnes of carbon per year. Disturbance of these forests would probably result in net release of CO2.
This research, if borne out by further studies, should provide strong motivation for forests of all ages to be included in carbon sequestration schemes. That means that owners of forests should be able to get income through the sale of carbon credits, and these owners will have an incentive for forest protection and conservation.
Links:
Lysseart et al in Nature (sub. required)
