Timber plantations are found across the globe, accounting for seven percent of the world’s total forest area. Plantations are typically managed on shortened harvest rotation lengths that optimize investment returns rather than longer rotations that would maximize yield for optimal broader economic and environmental benefits. Extending harvest rotation cycles would allow trees to absorb more carbon from the atmosphere while also increasing timber yields in tropical, subtropical, temperate and boreal forests.
Timber plantations cover some 257 million hectares globally – an area about the size of the US state of Oregon.
Extending harvest cycles to increase carbon uptake in timber plantations would sequester an additional 266 million metric tons of carbon dioxide equivalent per year (MtCO2e/year). That’s comparable to the emissions from 56 million passenger vehicles per year.
More analyses are needed to estimate the specific economic opportunity costs of implementing this pathway in various forest regions around the world. Those opportunity costs would likely need to be covered by carbon or other incentives. While such an analysis should be fairly straightforward, the work has not yet been done for each region in question.
While additional economic analysis is needed, we expect this will be a relatively low to moderate-cost pathway to implement. It is a straightforward change in practice that could begin almost immediately, without any changes to policy or land tenure.
Spotlight: Longleaf Pine in the Southeastern U.S.
In the Southeastern United States, tree plantations are typically planted with fast-growing species such as slash pine and loblolly pine. In some southeastern plantations, though, foresters are replacing those species with longleaf pine, a slow-growing tree with a deep taproot.
Longleaf pine is usually harvested on a longer rotation cycle, so these plantations are likely to increase long-term carbon uptake and storage. Furthermore, fast-growing species such as slash pine and loblolly pine are often used for pulp, yielding products that don’t offer long-term carbon storage benefits. Longleaf pine is typically used for products such as lumber and utility poles, which are more likely to provide longer-term carbon storage.
Similar changes to timber plantations could be used in the tropics where plantations are rapidly expanding, but will be particularly important in temperate and boreal regions, which house about two-thirds of the world’s timber plantations.