Dimensions, cover, volumes, mass and nutrient stores of Coarse Woody Debris (bark and wood from logs, snags, and stumps) from forests plots in the western United States and Mexico, 1977 to 2005

  • Creator(s): Mark E. Harmon
  • PI(s): Mark E. Harmon
  • Originator(s): Mark E. Harmon
  • Other researcher(s):
  • Dates of data collection: Jul 1 1977 - Aug 31 2005
  • Data collection status: Study collection is completed and no new collection is planned
  • Data access: Online
  • DOI:
  • Last update: Aug 25 2016 (Version 10)
<Citation>     <Acknowledgement>     <Disclaimer>    
Harmon, M. 2016. Dimensions, cover, volumes, mass and nutrient stores of Coarse Woody Debris (bark and wood from logs, snags, and stumps) from forests plots in the western United States and Mexico, 1977 to 2005. Long-Term Ecological Research. Forest Science Data Bank, Corvallis, OR. [Database]. Available: Accessed 2024-07-18.
Data were provided by the HJ Andrews Experimental Forest research program, funded by the National Science Foundation's Long-Term Ecological Research Program (DEB 2025755), US Forest Service Pacific Northwest Research Station, and Oregon State University.
While substantial efforts are made to ensure the accuracy of data and documentation, complete accuracy of data sets cannot be guaranteed. All data are made available "as is". The Andrews LTER shall not be liable for damages resulting from any use or misinterpretation of data sets.
These data provide an inventory of the mass and nutrients stored within various forest types by coarse woody debris (CWD). CWD inventoried includes standing dead trees (>10 cm diameter at breast height) and dead and downed wood (>10 cm large end and >1 long). The majority of measurements are from permanent sample plots associated with the Andrews LTER permanent sample plots network. This includes clusters of plots at and near the H. J. Andrews Experimental Forest (OR), Cascade Head Experimental Forest (OR), Mount Rainier National Park (WA), Olympic National Park (WA), and Fraser Experimental Forest (CO). There are also data from plots in the Yucatan in Mexico; however, the live tree data for these plots is not available. The species of CWD inventoried are primarily those found in the Pacific Northwest; the dominants being Douglas-fir, western hemlock, mountain hemlock, western redcedar, Pacific silver fir, noblel fir, lodgepole pine, ponderosa pine, sitka spruce, and Englemann spruce. The majority of measurements were made in the 1975 to 1995 period; however plots are periodically remeasured and the intent to eventually remeasure all the plots except those in Mexico. In each plot measurements of log and snag dimensions (length and diameters), as well as decay class and species were recorded in the stands (td01201 file). These dimension data are combined with data on density and nutrient content for each species and decay class (td01202 file) and plot area and slope (td01203 file) to calculate CWD volume, cover, biomass and nutrient storage (td01204 file). When data on density and nutrient concentrations is not known, a list of substitutions is used (td01206). The adjust tree diameters if measurements are taken at the base of the dead tree, taper regressions are used (td01205).

Study Description Study Site Map Taxonomic Hierarchy Download Study Location Information: (CSV)
Ecological Metadata Language: (EML)
1Field dimension data (Jul 1 1977 - Aug 31 2005)METADATADATA
2Density and Nutrient Concentration Data METADATADATA
3Plot Area and Slope Correction File METADATADATA
4Summaries for Volume, Mass, Cover, and Nutrients (Jul 1 1977 - Aug 31 2003)METADATADATA
5Regressions of Stump Diameter on DBH and Stump Height METADATADATA
6Lookup table for susbtitution species used by CWD program to produce summaries in Entity 4 METADATADATA

 Harmon, Mark E. 1989, Effects of bark fragmentation on plant succession on conifer logs in the Picea - Tsuga forests of Olympic National Park, Washington (Pub. No: 959)
 Harmon, Mark E., Cromack, Kermit, Jr., Smith, Bradley G. 1987, Coarse woody debris in mixed-conifer forests, Sequoia National Park, California (Pub. No: 9)