Global forests capture and store significant amounts of carbon through photosynthesis. When carbon is removed from forests through harvest, a portion of the harvested carbon is stored in wood products, often for many decades. The United States Forest Service (USFS) and other agencies are interested in accurately accounting for carbon flux associated with harvested wood products (HWP) to meet greenhouse gas monitoring commitments and climate change adaptation and mitigation objectives. National-level forest carbon accounting has been in place for over a decade, but there is an increasing need for accounting for smaller scale administrative units, including USFS National Forest System regions and individual National Forests. This paper uses the Intergovernmental Panel on Climate Change (IPCC) production accounting approach to estimate HWP carbon storage from 1906 to 2012 for the USFS Rocky Mountain Region. For the Rocky Mountain Region as a whole, carbon stocks in the HWP pool were increasing at approximately 180,000 megagrams of carbon (MgC) per year in the early 1950s through 1995 when carbon stocks plateaued until 2005 followed by the peak cumulative storage to date of 12 million MgC occurring in 2013. Net positive flux into the HWP pool over this period is primarily attributable to high harvest levels in the early1950s through the 1990s. In the years between the mid-1960s and 1990 timber harvests were at high, volatile levels, with high harvests of over 800,000 ccf (600,000 MgC) occurring six times during this period. Harvest levels from National Forests of the Rocky Mountain Region have since declined to less than 470,000 ccf (350,000 MgC) per year, resulting in less carbon entering the HWP pool. With the exceptions of 1998, 2003 and 2004, when emissions from HWP at solid waste disposal sites exceeded additions from harvesting, the Rocky Mountain Region HWP pool has remained in a period of positive net annual stock change because additions of carbon to the HWP pool through harvest exceeds the decay of products harvested between 1906 and 2012. Together with estimates of ecosystem carbon, which are also being developed through the Forest Management Carbon Framework (ForCaMF), Regional level estimates of HWP carbon flux can be used to inform management decisions and guide climate change adaptation and mitigation efforts by the agency. Though our emphasis is on the Rocky Mountain Region as a whole, this accounting method can be applied at smaller land management units, such as National Forests.
Stockmann, Keith; Anderson, Nathaniel; Young, Jesse; Skog, Ken; Healey, Sean; Loeffler, Dan; Butler, Edward; Jones, J. Greg; Morrison, James. 2014. Estimates of carbon stored in harvested wood products from United States Forest Service Rocky Mountain Region, 1906-2012. Unpublished report. Missoula, MT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Forestry Sciences Laboratory. 27 p.