I’ve been wondering if there is a straightforward answer to the question of how to best manage forest lands to sequester carbon for the foreseeable future to reduce potential climate change impacts. We’ve beaten around that bush a few times, such as here.
I thought such an answer might be found in the kind of forest management activities carbon offset programs are willing to pay for. I recently ran across this example, which describes two new programs for small forest landowners.
“Forest carbon projects have historically faced skepticism around their additionality and potential for leakage — that is, the shifting of tree removals to nearby acreage. The concern is that despite paying a landowner to keep trees on one parcel, the same number will simply be removed elsewhere, resulting in a null offset with no net change in carbon storage. Yet SilviaTerra believes this problem can be addressed by creating a market in which all landowners are eligible to receive carbon payments as an alternative to timber revenues… Payments are scaled to target the timeframe when forests have matured to a point of likely timber harvest… SilviaTerra believes that timber harvest deferrals hold the potential for removing over a billion tons of atmospheric carbon within the United States in the coming decade, or 4.3 billion tons globally.”
SilviaTerra is paying landowners to not harvest mature trees now, and presumably they would continue to do that indefinitely for a parcel because, (according to this article on the carbon value of old forests), “We now know that the concept of overmature forest stands, used by the timber industry in reference to forest products, does not apply to carbon.” The Family Forest Carbon Program pays for “improved forest management practices,” “such as removal of invasive species or limiting thinning.” Both seem to treat the answer to my question as obvious – the best management for carbon is “don’t cut down trees.”
Here is what the Forest Service has had to say about the best available science. This 2017 General Technical Report covers a lot of the pros and cons and questions and considerations and reservations that we have previously discussed, such as wood products, wood energy and fire risk, but if the goal is to “maintain and increase carbon stocks,” the best answer appears to be “decrease carbon loss:”
“Decreasing the intensity of forest harvest is one way to decrease carbon losses to the atmosphere (McKinley et al. 2011, Ryan et al. 2010). Across diverse forest systems, the “no harvest” option commonly produces the highest forest carbon stocks (Creutzburg et al. 2015, Nunery and Keeton 2010, Perez-Garcia et al. 2007).”
The Report was written for a broad audience of landowners and managers, so it also discusses options for managed stands:
“Managed stands typically have lower levels of forest biomass than unmanaged stands, even though the annual rate of sequestration may be higher in a younger forest. In managed forests, reducing harvest intensity, lengthening harvest rotations, and increasing stocking or retention levels will generally increase the amount of carbon stored within forest ecosystem carbon pools in the absence of severe disturbance (D’Amato et al. 2011, Harmon 2001, Harmon and Marks 2002, McKinley et al. 2011, Taylor et al. 2008b).”
However, they also provide caveats and qualifiers associated with obtaining overall carbon benefits from any strategy that removes trees, which make it clear this would likely be a second-best strategy for carbon sequestration.
With regard to national forests, the Report recognizes the role of NFMA and forest plan revisions:
“Assuming carbon is one of these key ecosystem services, the plan should describe the desired conditions for carbon in the plan area that may vary by management or geographic area. In developing plan objectives, the interdisciplinary team should consider the linkage between carbon and how plan objectives would contribute to carbon storage or sequestration. Standards and guidelines may also be needed to achieve desired outcomes for carbon.”
We shouldn’t have to just assume the importance of carbon sequestration, since that is a decision a forest plan could make. With an incoming administration that has said it would integrate climate change into everything it does, a good question to ask them would be why should the Forest Service not establish in its forest plans the desired outcome to “maintain and increase carbon stocks.” This should create a presumption or default that trees should not be removed unless the Forest Service can demonstrate scientifically that it would improve carbon sequestration (apparently difficult to do), or if it would meet some other goal that the planning process has determined is a higher priority than climate change (such as public safety). Climate change mitigation has typically been diverted to a side-channel during forest planning, but there doesn’t seem to be any excuse now for why at least managing for carbon sequestration isn’t mainstream.
