Plant succession and biomass dynamics following logging and burning in Watersheds 1 and 3, Andrews Experimental Forest, 1962 to Present

  • Creator: C. Ted Dyrness, Charles B. Halpern
  • PI: Charles B. Halpern
  • Originator: C. Ted Dyrness
  • Other researchers: Robert J. Pabst, David Bell, David Carl Shaw, Andrew Bluhm, Jerry F. Franklin, James A. Lutz
  • Dates of data collection: Jan 1 1962 - Jul 16 2019
  • Data collection status: Study continues and further data collection is planned
  • Data access: Online
  • DOI:
  • Last update: Apr 16 2021 (Version 18)
<Citation>     <Acknowledgement>     <Disclaimer>    
Dyrness, C.; Halpern, C. 2021. Plant succession and biomass dynamics following logging and burning in Watersheds 1 and 3, Andrews Experimental Forest, 1962 to Present. Long-Term Ecological Research. Forest Science Data Bank, Corvallis, OR. [Database]. Available: Accessed 2022-01-23.
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.
Watersheds 1 and 3 in the HJ Andrews Experimental Forest have a long history of hydrologic, geomorphic, and ecological study. Long-term successional studies in the two watersheds are unprecedented in their scope and duration (1962 to present), spanning more than 50 years of post-logging measurements. To date, studies have focused on understory responses to logging and burning, early stand developmental processes (tree growth and mortality), and understory responses to canopy closure. Understory sampling was initiated in 1962, prior to harvest, and includes approximately 190, 2 x 2 m permanent understory plots. Measurements include estimates of ground-surface conditions and abundance (cover and biomass) of herbaceous, shrub, and tree species. Plots were sampled annually through 1972/1973, but less frequently thereafter (every 2-6 years). Studies of early stand development were initiated in 1979/1980 in conjunction with the understory plots. In each of approximately 190, 250 m2 tree plots all conifer and hardwood stems greater or equal to 1.4 m tall are tagged, measured for diameter, and assessed for status (live or dead, including the cause of mortality). Both watersheds have experienced recent snow-related windthrow (2019, 2020) and parts of WS1 have burned in a low-severity wildfire (2020) adding complexity to early successional outcomes.

Study Description Study Site Map Taxonomic Hierarchy Download Study Location Information: (CSV)
Download Full Documentation: (PDF)(EML)
1Watersheds 1 and 3 Succession Plots -- Plot descriptions: Vegetation and soil classifications with location, elevation, aspect and slope measurements (Jun 25 2002 - Jul 21 2013)METADATADATA
2WS1 & 3 Succession Plots -- Cover, frequency, and biomass related data (Sep 25 1979 - Oct 27 2017)METADATADATA
3WS1 & 3 Succession Plots -- Tagged trees: Diameter data (Jun 13 1979 - Jul 16 2019)METADATADATA
4WS1 & 3 Succession Plots -- Tagged trees: Height data (Jun 21 1979 - Sep 11 1979)METADATADATA
5WS1 & 3 Succession Plots -- Canopy closure (Jun 25 1990 - Feb 27 2017)METADATADATA
6Reference trees for plot center re-location (Jun 27 2017 - Oct 27 2017)METADATADATA

 Plot Layout - Layout of tree plots and understory vegetation quadrats (post-1978)
 Sampling Protocol (2017) - Sampling protocols for trees and understory vegetation (2017)
 Tree Sampling Protocol (2007) - Sampling protocols for trees (modified for 2007)
 Vegetation Sampling Protocol (2008) - Sampling protocols for understory vegetation (modified for 2008)

 Long-term growth, mortality and regeneration of trees in permanent vegetation plots in the Pacific Northwest, 1910 to present (TV010)
 Species interactions during succession in the western Cascade Range of Oregon, 1990 to present (TP103)
 Post-logging community structure and biomass accumulation in Watershed 10, Andrews Experimental Forest , 1974 to present (TP041)
 Ecosystem dynamics in a mature (Hagan block) and old-growth (Watershed 2) forest, Andrews Experimental Forest, 1981 to present (TP091)
 Plant biomass dynamics following logging, burning, and thinning in Watersheds 6 and 7, Andrews Experimental Forest, 1979 to present (TP114)
 Plant biomass dynamics in old-growth Watersheds 8 and 9 at the Andrews Experimental Forest, 2003 to present (TP115)

 Halpern, C.B., Lutz, J.A. 2013, Canopy closure exerts weak controls on understory dynamics: A 30-year study of overstory-understory interactions (Pub. No: 4786)
 Dovciak, Martin, Halpern, Charles B. 2010, Positive diversity-stability relationships in forest herb populations during four decades of community assembly (Pub. No: 4578)
 Lutz, James A., Halpern, Charles B. 2006, Tree mortality during early forest development: a long-term study of rates, causes, and consequences (Pub. No: 4017)
 Lutz, James A. 2005, The contribution of mortality to early coniferous forest development (Pub. No: 3931)
 Acker, S. A., Halpern, C. B., Harmon, M. E., Dyrness, C. T. 2002, Trends in bole biomass accumulation, net primary production and tree mortality in Pseudotsuga menziesii forests of contrasting age (Pub. No: 2824)
 Halpern, Charles B., Spies, Thomas A. 1995, Plant species diversity in natural and managed forests of the Pacific Northwest (Pub. No: 1526)
 Halpern, Charles B., Franklin, Jerry F., McKee, Arthur 1992, Changes in plant species diversity after harvest of Douglas-fir forests (Pub. No: 1405)
 Halpern, Charles B., Franklin, Jerry F. 1990, Physiognomic development of Pseudotsuga forests in relation to initial structure and disturbance intensity (Pub. No: 1129)
 Halpern, Charles B. 1989, Early successional patterns of forest species: interactions of life history traits and disturbance (Pub. No: 956)
 Halpern, Charles B. 1988, Early successional pathways and the resistance and resilience of forest communities (Pub. No: 764)
 Dyrness, C. T. 1973, Early stages of plant succession following logging and burning in the western Cascades of Oregon (Pub. No: 429)
 Dyrness, C. T. 1969, Hydrologic properties of soils on three small watersheds in the western Cascades of Oregon (Pub. No: 372)
 Rothacher, Jack, Dyrness, C. T., Fredriksen, Richard L. 1967, Hydrologic and related characteristics of three small watersheds in the Oregon Cascades (Pub. No: 344)