Soil Carbon Sequestration in U.S. Rangelands ⋆ Savory Institute

Whitepaper

Soil Carbon Sequestration in U.S. Rangelands

Environmental Defense Fund

Fynn, A.J., P. Alvarez, J.R. Brown, M.R. George, C. Kustin, E.A. Laca, J.T. Oldfield, T. Schorh, C.L. Neely, and C.P. Wong. 2009. Soil carbon sequestration in U.S. rangelands: Issues paper for protocol development. New York: Environmental Defense Fund.

Key Takeaways

This Environmental Defense Fund issues paper from 2009 recognized the magnitude of rangelands as a global ecosystem (up to half the land surface area of the planet) and of rangeland soils as a carbon sink suitable to mitigate global warming through proper management actions (“protocols”).
It states that on the 761 million acres of rangelands in the United States, 198 million tons of atmospheric carbon dioxide (CO2) - or 3.3% of US fossil fuel emissions - could be sequestered into newly formed soil each year for 30 years.
Several actions for soil improvement on rangelands are presented, the number one of which is “Conversion of abandoned and degraded cropland to grassland.”
Some other recommended actions include avoiding conversion of rangeland to croplands in the first place, extensive grazing management (that does not require infrastructure development) and adjusting stocking rates. Other, non-grazing related actions, include reseeding of grasslands and introduction of black carbon (biochar) into the soil.

Summary

Rangelands are uncultivated lands that include grasslands, savannas, steppes, shrublands, deserts and tundra. The native vegetation on rangelands is predominantly grasses, forbs and shrubs (Kothmann 1974). Rangelands cover 31% of the land surface area of the United States (Havstad et al. 2009), and up to half of the land surface area worldwide (Svejcar et al. 2008, Lund 2007). Most land areas that are not developed, not cultivated, not forested, and not solid rock or ice can be classified as rangelands. Because of their extent, a small change in soil carbon stocks across rangeland ecosystems would have a large impact on greenhouse gas accounts.

There are 761 million acres of rangelands in the U.S. (Havstad et al. 2009), half of which is public lands in the West (Follett et al. 2001). The primary activity focus on rangelands is grazing. Rangelands and grazing lands and are two broadly overlapping categories. U.S. grazing lands, including managed pasturelands, have the potential to remove an additional 198 million tons of carbon dioxide (CO2) from the atmosphere per year for 30 years (Follett et al. 2001). This would offset 3.3 % of U.S. CO2 emissions from fossil fuels (EIA 2008), and help protect rangeland soil quality for the future.