Old-growth forests store a lot more carbon than managed forests - Lund University

Swedish old-growth forests store 83 percent more carbon than managed forests, according to a new study from Lund University. The difference is substantially larger than previous estimates and is mainly due to large carbon stocks in the soil.

The study, published in the scientific journal Science, is the most comprehensive mapping of how much carbon is stored in Swedish old-growth forests to date. The results show that old-growth forests store 78–89 per cent more carbon than managed forests in living trees, dead wood, and in the soil down to a depth of 60 centimetres.

“The most surprising result is the large amounts of carbon stored in the soil of old-growth forests. It is the same amount as all the carbon in managed forests - trees, dead wood, and soil, combined,” says Anders Ahlström, researcher at the Department of Environmental and Earth Sciences at Lund University.

The work behind the study took nearly ten years. Because there was no national map of old-growth forests, the researchers first had to identify and map forests that had been very little affected, or not affected at all, by direct human activity. Extensive fieldwork was then carried out across the country, including nearly 220 soil pits dug to a depth of one meter to measure carbon storage in the soil.