Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.The Carbon Management Evaluation Tool for Voluntary Reporting (COMET-VR) is an online tool that estimates short-term carbon stock (CS) changes under different farm or forest land management systems, including temperate agroforestry practices. It was developed by the USDA Natural Resources Conservation Service in conjunction with Colorado State University. The intended audience includes private farm and forest landowners, NRCS field staff, and technical service providers. Through the online interface, users identify their location, parcel size, surface soil texture, crop rotation history and tillage intensity. The user can choose either of two methods to estimate CS change for their agroforestry practice: 1) for new or future plantings, by using standard prescriptions common to their geographic region, or 2) for a more accurate estimate of an existing planting, by using a summary of live-tree stand inventory data collected from their parcel. Above and below-ground individual tree biomass is calculated using diameter-based allometric equations generalized for tree genera groups. For existing agroforestry plantings, growth estimates are based on empirical models developed from forest inventory data specific to species and region. For new or future plantings, growth estimates were derived for standard agroforestry prescriptions using the Forest Vegetation Simulator. COMET-VR uses the Century soil carbon model to estimate CS change in soil. The output of the tool is a report estimating CS changes over the forthcoming 10 years in the above and below-ground portions of live trees and in the soil. Although specifically designed to meet the requirements of the US Dept. of Energy voluntary greenhouse gas reporting program, COMET-VR may also be applicable to other private and public sector carbon offset programs.Miles L. Merwin (1), Mark Easter (2), Lyn R. Townsend (1), Roel C. Vining (1) and Greg L. Johnson (1) ; 1. USDA Natural Resources Conservation Service, 1201 NE Lloyd Blvd., Portland, OR 97232. 2. Natural Resource Ecology Laboratory, Colorado State University, Ft. Collins, CO.Includes bibliographical references
