Sampling Protocol, Estimation, and Analysis Procedures for the Down Woody Materials Indicator of the FIA Progam

The Forest Inventory and Analysis (FIA) program of the USDA Forest Service conducts a national inventory of forests of the United States. A subset of FIA permanent inventory plots are sampled every year for numerous indicators of forest health ranging from soils to understory vegetation. Down woody material (DWM) is an FIA indicator that provides estimates of forest structural diversity, forest area fuel loadings, and national carbon sources. DWM comprises fine woody debris, coarse woody debris, slash piles, duff, litter, and shrub/herbs. Components of DWM are sampled using the lineintersect method and fixed-radius sampling. DWM data analyses serve as integral parts of national inventory reporting requirements, regional/national forest health reports, wildlife habitat assessments, and fuel loading maps. The DWM inventory began in 2001 and is currently implemented in 38 States. The goal of this document is to provide the rationale and context for a national inventory of down woody material; document the various woody material components sampled by the DWM indicator, the sampling protocol used to measure the DWM components, and estimation procedures; and provide guidance on managing and processing DWM data and incorporating that data into pertinent inventory analyses and research projects. Published by: North Central Research Station Forest Service U.S. Department of Agriculture 1992 Folwell Avenue St. Paul, MN 55108 2005 Web site: www.ncrs.fs.fed.us The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, and marital or family status. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326-W, Whitten Building, 1400 Independence Avenue, SW, Washington, DC 20250-9410 or call (202) 720-5964 (voice and TDD). USDA is an equal opportunity provider and employer. Cover photos (clockwise): Burnt ponderosa pine log near Prescott, AZ; snail on coarse woody debris in Great Smoky Mountains, NC; fine woody debris near Salinas, CA; and riparian coarse woody debris in Pisgah National Forest, NC.