New study: mature forests on federal lands are essential to our climate future

As trees age, they absorb and store more carbon than smaller trees and as the entire forest matures, it collectively accumulates massive amounts of carbon over centuries in vegetation and soils.

Forests

January 17, 2023

Bureau of Land Management California via Flickr | Public Domain

A new study published in the peer-reviewed journal Forests and Global Change presents the nation’s first assessment of carbon stored in larger trees and mature forests on 11 national forests from the West Coast states to the Appalachian Mountains.

Key findings include:

The minimum age at which forests may be considered mature, according to peak carbon capture, ranged from 35 to 75 years.
The carbon stored in all trees of the 11 forests totaled 561 million metric tons, of which 73% is in larger trees and 60% is in unprotected larger trees in mature stands.
For 8 of the 11 forests that had carbon accumulation data, the annual rate was 4.7 million metric tons per year, of which about half is in unprotected larger trees in mature stands.
Forest stands with the greatest carbon stored and highest annual carbon accumulation were mainly in the Pacific Northwest, and all but one of the national forests (Black Hills in South Dakota due to drought and insect related tree mortality) experienced an increase in above-ground carbon over recent years.

The authors of the study are Richard A. Birdsey (Woodwell Climate Research Center), Dominick A. DellaSala (Wild Heritage, A Project of Earth Island Institute), Wayne S. Walker (Woodwell Climate Research Center), Seth R. Gorelik (Woodwell Climate Research Center), Garett Rose (Natural Resources Defense Council) and Carolyn E. Ramírez (Natural Resources Defense Council).