Comparison of terrestrial versus aquatic decomposition rates of logs at the Andrews Experimental Forest, 1985 to 2050

  • PI: Mark E. Harmon
  • Originator: Mark E. Harmon
  • Other researchers:
  • Dates of data collection: Jun 4 1985 - Nov 10 1999
  • Data collection status: Study continues and further data collection is planned
  • Data access: Online
  • Last update: Nov 25 2015 (Version 8)
<Citation>     <Acknowledgement>     <Disclaimer>    
Harmon, M. 2015. Comparison of terrestrial versus aquatic decomposition rates of logs at the Andrews Experimental Forest, 1985 to 2050. Long-Term Ecological Research. Forest Science Data Bank, Corvallis, OR. [Database]. Available: (18 June 2018) DOI:
Data were provided by the HJ Andrews Experimental Forest research program, funded by the National Science Foundation's Long-Term Ecological Research Program (DEB 1440409), 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.
The data collected from this study describe the decomposition of small logs (20-30 cm diameter, 2 m length) a stream channel to those on an adjacent upland site at the H. J. Andrews Experimental Forest. The stream is a 3rd order above the junction of Lookout Creek and Mack Creek. Three species of trees are being examined: Douglas-fir, western hemlock, and red alder. Data collection started in 1985 and is scheduled to continue to 2050. Periodically a subset of logs is resampled to determine changes in volume, bark cover, density, and nutrient stores. The last set of samples was collected in 2005. Logs ranging in diameter between 20 and 30 cm of a length of 2 m were cut out of live trees of the three species. Logs were placed by hand along a skid road at the terrestrial site. A cable system was used to place log randomly along a stream reach. The location of logs in the stream is noted when they are sampled. The length and diameter as well as bark cover of each sampled log is noted at the time of sampling (td01701). Six cross-sections are removed with a chainsaw. The thickness of the tissue types is noted (inner bark, outer bark, sapwood, and heartwood) and are described in td01702. Samples of each tissue type are taken to determine their moisture content (water mass/dry mass) and density (dry mass/green volume). Density is derived from dry mass and volume as determined via dimensional measurements. Dimensional data, volumes, masses, density, and moisture content are documented in the td01703 table. The volume of logs and tissue types, the total mass, and proportional mass of the tissue types as well as moisture contents is derived from the data in the other data tables and is stored in the td01704 table.

Study Description Taxonomic Hierarchy Download Study Location Information: (CSV)
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1Log Descriptions Including Length, Diameters, Bark Cover METADATADATA
2Radial Thickness Of Tissue Types METADATADATA
3Sample Dimensions, Weights, Density, and Moisture Contents METADATADATA
4Log Volumes, Tissue Volumes, Total Mass, Proportional Mass METADATADATA