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

  • Creator(s): Charles B. Halpern, C. Ted Dyrness
  • PI(s): Charles B. Halpern
  • Originator(s): C. Ted Dyrness
  • Other researcher(s): Robert J. Pabst, David Bell, David Carl Shaw, Andrew Bluhm, Jerry F. Franklin, James A. Lutz
  • Dates of data collection: Jan 1 1962 - Jun 29 2022
  • Data collection status: Study continues and further data collection is planned
  • Data access: Online
  • DOI:
  • Last update: Jul 29 2022 (Version 19)
<Citation>     <Acknowledgement>     <Disclaimer>    
Halpern, C.; Dyrness, C. 2022. 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 2024-06-15.
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. After broadcast burning (1963 in WS3, 1966 in WS1) 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, with sample plots collocated with the understory plots. In each of approximately 190, 250 m2 tree plots, all conifer and hardwood stems greater than 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 experienced recent snow-related windthrow (2019, 2020) and parts of WS1 burned in 2020 during the Holiday Farm Fire, adding complexity to the structure and composition of the understory and overstory communities.

Study Description Study Site Map Taxonomic Hierarchy Download Study Location Information: (CSV)
Ecological Metadata Language: (EML)
1Plot locations and biophysical attributes (Jun 25 2002 - Jul 21 2013)METADATADATA
Plot characteristics including UTMs, latitude/longitude, topographic attributes (elevation, aspect, and slope), plant community and soil type, and disturbance class (post-logging/burning)
2Cover, frequency, and biomass-related data (Sep 25 1962 - Jun 29 2022)METADATADATA
Frequency, cover, and biomass-related measurements (diameter, height, and stem counts) for plant species; cover of plant growth forms; and cover of ground-surface characteristics
3Tagged trees: diameter, vigor, and status including mortality (Jun 21 1979 - Nov 3 2021)METADATADATA
Individual tree measurements including basal diameter, DBH, counts of hardwood stems by size class (through 2000), vigor, status (live or dead), and location within the plot
4Tagged trees: Height data (Jun 21 1979 - Sep 11 1979)METADATADATA
Individual tree diameter, height, and leader length at plot establishment (1979)
5Overstory canopy cover/closure (Jun 25 1990 - Jun 29 2022)METADATADATA
Measurements of canopy cover/closure above and adjacent to understory quadrats; includes the contributions of tall shrubs, hardwood trees, and conifers
6Bearings and distances from reference trees to plot centers, and comments on plot conditions (Jun 27 2017 - Jun 29 2022)METADATADATA
Bearings and distances from tagged reference trees to plot centers (used to reposition center-point rebars as needed); also includes comments on plot conditions and damage to, or absence of, PVC posts marking the corners of vegetation quadrats
7Tagged tree burn severity and canopy scorch (Jun 29 2021 - Nov 3 2021)METADATADATA
Burn severity ratings and percent canopy scorch for individual trees in Watershed 1 in 2021, resulting from the 2020 Holiday Farm Fire

 Plot Layout - Layout of tree plots and understory vegetation quadrats (post-1978)
 Plot Sampling History - Sampling history for trees and understory by year (Excel file)
 Sampling Protocol (2021) - Sampling protocols for trees and understory vegetation (2021)
 Sampling Protocol (2017) - Sampling protocols for trees and understory vegetation (2017)
 Vegetation Sampling Protocol (2013) - Sampling protocols for understory vegetation (modified for 2013)
 Tree Sampling Protocol (2012) - Sampling protocols for trees (modified for 2012)
 Vegetation Sampling Protocol (2008) - Sampling protocols for understory vegetation (modified for 2008)
 Tree Sampling Protocol (2007) - Sampling protocols for trees (modified for 2007)

 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)