The Crested Butte News Serving the Gunnison Valley since 1999
“One of the biggest things we can do is keep forests as forests”
By Katherine Nettles
As anyone even casually surveying the Gunnison Valley’s landscapes can tell, it is an area of densely forested lands, and a new study released last month has confirmed how impactful those forests are in carbon sequestration and storage.
Gunnison County boasts more than two million acres of public lands alone, much of which is heavily forested, and thousands more acres of privately owned land. In early January, the Colorado State Forest Service (CSFS) released the results of its forest carbon study, which spans from 2002-2019 and uses data from forests within Gunnison County and across the state to assess overall carbon storage, as well as the annual sequestration (addition) and release (loss) of carbon. The Forest Carbon Inventory found that Colorado’s forests hold a great deal of carbon but have overall released more carbon in the past decade than they have added. However, the inventory shows that Colorado’s forest carbon stocks are higher, and emissions are lower than other studies have estimated. Furthermore, forests within the western half of the state, including those found in the Gunnison Valley, have demonstrated some of the highest levels of carbon storage and lowest emissions.
The 2020 Colorado Forest Action Plan recognized the need for a statewide forest carbon analysis, and state legislation in 2022 subsequently directed the agency to conduct this study to better understand the role of the state’s forests in mitigating climate change and wildfire risk, and to inform future land use management. The CSFS, in collaboration with researchers at Colorado State University, developed this statewide inventory, which examines forest ecosystems across the state and the harvested wood products (lumber, furniture, panels) from those forests. It also uses a nation-wide program called Forest Inventory Analysis (FIA).
The science
To calculate carbon stocks (storage), the study used data from the most recent 10 years of available plot data (from 2010 to 2019), in forest plots all over Colorado, including more than 100 FIA plots within Gunnison County on both privately and publicly owned land. Researchers calculated the average annual net carbon change (flux) by comparing plots and individual trees initially measured between 2002 and 2009 and remeasured from 2012 to 2019. The change in forest carbon is calculated by tracking the growth, removals and mortality of trees re-measured ten years apart, according to the report.
The study found that most FIA forest type groups were net sources of carbon (releasing more carbon into the atmosphere than is sequestered) during this period, although the ponderosa pine and woodland hardwoods were weak carbon sinks (absorbing more carbon than is released). The aspen group showed the greatest net carbon loss, and the report states that nearly half of Colorado’s forest carbon was stored in two forest type groups: the fir/spruce/mountain hemlock (29%) and the pinyon/juniper (20%).
Local results
The western half of Colorado contains more forested land than eastern Colorado, which the study found to be reflected in the higher carbon stocks in the northwest and southwest areas as compared to the northeast and southeast areas of study. Gunnison is one of the top 10 counties with the highest carbon
stocks, along with Saguache, Montrose, Mesa, Garfield, Rio Blanco, Routt, Grand, Eagle and Larimer. The Northwest and Southwest areas were net carbon sources, with the Northwest area being the largest source.
Ashley Prentice, a forest carbon specialist with the CSFS and co-author of the inventory report, has lived in the North Valley and studied forests across the GMUG for several years as an undergraduate at Western Colorado University, later as a graduate student and now with the CSFS.
Prentice said that while the report does not provide estimates at a finer scale than the county level, “I can share from my time exploring public lands in the valley that high-elevation carbon-dense spruce/fir dominated forests, such as the forests around the Anthracites, Axtel, and Whetstone, and areas around Paradise Divide, Gothic, and Double Top contribute to the overall high carbon stock in Gunnison County.” She said that a lot of carbon is stored in the soil, which holds about 60% of statewide carbon stocks.
“One of the biggest takeaways is that this is the first report for Colorado that goes into this level of detail,” says Prentice. “It is also the first report to look at how carbon is stored in harvested wood products, which was calculated from local mill surveys.” The study assessed mill survey data going back to the 1950s to model how much carbon is stored in wood products in use and those products which have been retired, and how that carbon changes over time. Researchers found that these products contributed to less than 1% of carbon stocks in the state.
“When people talk about management implications or policy recommendations based on that information, its important to understand first that we certainly don’t have the same wood harvesting industry as states in the Pacific Northwest or the east coast,” Prentice points out. “As opportunities arise for active management and as new timber markets develop, such as mass timber, long-term forest health and long-term carbon storage in harvested wood products are critical to the conversation.
Those involved in this inventory have said as the inventory is updated periodically with new data, including capturing the effects of the 2020 fire season, they expect the statewide net carbon emissions to increase, due to ongoing disturbances and mortality.
“It’s also important to note that these areas around Gunnison have ongoing insect and disease outbreaks—the spruce bark beetle, western balsam beetle, and spruce budworm have increased activity in recent years. They are native insects and play an important role in the ecosystem with decomposition and nutrient cycling. We do expect future inventories to reflect more of the impacts from these recent disturbances for Gunnison County,” says Prentice.
She added, “Our [forest] growth rates are not keeping up with the level of mortality. In areas that are not able to regenerate on their own, where there’s no seed source, lack of moisture, or competition with shrublands- those are great areas to plant seedlings.”
However, she cautions that “We are not going to re-plant our way out of this. Reforestation is one strategy to reduce the loss of forest and can mitigate some of those carbon losses over the long-term. One of the biggest things we can do is keep forests as forests.”
Prentice also cautions that while this inventory is important and will pave the way for continual monitoring, forest carbon is just one aspect of land management, and carbon quantities, whether a source or a sink, don’t entirely define a healthy ecosystem because they shift over time. “It should be something we think about along with other management priorities over time,” she concludes.
“This report provides a baseline for understanding how much carbon is stored in our forests and how these amounts change over time,” said Colorado state forester (and former district ranger for the GMUG) Matt McCombs. “The results will inform strategies for forest and carbon management, helping us understand our forests’ potential to lessen the impacts of climate change, make our communities more resilient and meet Colorado’s bold climate goals.”
“This was a big collaborative effort,” notes Prentice. The state partnered with Colorado State University and several agencies in the Pacific Northwest. “It’s a good example of undertaking a truly ambitious project and working with a lot of partners to bring it to fruition.”
