Higher carbon storage in primary than secondary boreal forests in Sweden
Summary
Boreal forests provide considerable global land carbon storage and uptake, but they are being rapidly transformed to managed secondary forests, with poorly quantified implications for ecosystem carbon storage. Here we present data from extensive mapping and field inventories of carbon storage in primary forests in Sweden and use multiple methods to show that primary forests store ~72% (70 to 74% across methods) more carbon than managed secondary forests in vegetation, deadwood, soils, and
Content
# Higher carbon storage in primary than secondary boreal forests in Sweden
*Published: 2026 Mar 19*
Boreal forests provide considerable global land carbon storage and uptake, but
they are being rapidly transformed to managed secondary forests, with poorly
quantified implications for ecosystem carbon storage. Here we present data from
extensive mapping and field inventories of carbon storage in primary forests in
Sweden and use multiple methods to show that primary forests store ~72% (70 to
74% across methods) more carbon than managed secondary forests in vegetation,
deadwood, soils, and harvested wood products combined. Soils constitute both the
largest carbon store and the largest difference between these forest types. The
total carbon storage difference between primary and managed secondary forests is
2.7 to 8.0 times larger than previous estimates. Our results challenge estimated
past and future contributions of boreal forest management to atmospheric carbon
dioxide concentrations.
DOI: 10.1126/science.adz8554