Species interactions during succession in the western Cascade Range of Oregon, 1990 to present

  • Creator: Charles B. Halpern
  • PI: Charles B. Halpern
  • Originator: Charles B. Halpern
  • Other researchers: Joseph A. Antos, Annette M. Olson, Kermit Cromack Jr.
  • Dates of data collection: Jul 1 1990 - Jul 4 2019
  • Data collection status: Study continues and further data collection is planned
  • Data access: Restricted: proprietary (publication issues)
  • DOI:
  • Access constraint: Please contact the PI directly if you download these data. Data collected from past 3 years have not been released; contact PI for access to these data.
  • Last update: Jul 24 2019 (Version 17)
<Citation>     <Acknowledgement>     <Disclaimer>    
Halpern, C. 2019. Species interactions during succession in the western Cascade Range of Oregon, 1990 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.
The factors that contribute to plant species establishment and decline following disturbance determine the rates and patterns of successional change of a system. In this long-term field experiment, we test the commonly held assumption that competition for space or resources by dominant species determines the outcome of succession. Specifically, we examine the population- and community-level consequences of removing one or more potentially dominant species from the post-disturbance community after clearcut logging and burning of a mature/old-growth Douglas-fir forest. Experimental treatments include: (1) removal of early-seral annual, Senecio sylvaticus, or perennial, Epilobium angustifolium—or both—to test the influences of these early-seral dominants on subsequent community development; (2) removal of all species except Senecio or Epilobium, to test whether the decline of these early-seral dominants is driven by competitive displacement; or (3) removal of shade-tolerant forest species that dominate subsequent stages of succession—Rubus ursinus or Berberis nervosa plus Gaultheria shallon—to test the influences of these long-lived perennials on understory development. The experiment is a randomized block design comprising eight removal treatments plus a control replicated in each of 25 blocks. Removal (reduction in competition) is achieved by removing seedlings or vegetative stems annually from a treatment area of 2.5 x 2.5 m. Sample plots (1 x 1 m) centered within these are used to estimate cover of all vascular plant species and, for the first 8 yr of the experiment, stem density and height, facilitating estimates of above-ground biomass. Pre-harvest data were collected in 1990, logging/burning occurred in 1991, and removal treatments and post-treatment sampling were initiated in 1992. Six of the nine experimental treatments were terminated between 1996 and 1998, with loss of early-seral Senecio and Epilobium from the system. The remaining three treatments (removal of Rubus, removal of Berberis plus Gaultheria, and the control) have been sampled annually since 1992. All regeneration of trees within the experimental area has occurred naturally. In September 2018, the study site partially burned during the larger Terwilliger Fire on the Willamette National Forest. In 2019, plots were assessed for burn severity. Species' removals were terminated, but cover measurements continue in the plots.

Study Description Study Site Map Taxonomic Hierarchy Download Study Location Information: (CSV)
Download Full Documentation: (PDF)(EML)
1Species Cover, Density, and Biomass Measurement Data (Jun 1 1990 - Jul 4 2019)METADATADATA
2Species Removals (counts) (Jun 1 1990 - May 17 1998)METADATADATA
3Species Cover, Density, and Biomass Measurements Original Fieldsheet Format (Jun 1 1990 - Aug 15 1996)METADATADATA
4Species Cover, Density, and Biomass Measurements Modified Fieldsheet Format (Jun 1 1997 - Jul 14 1999)METADATADATA
5Equations used for calculating biomass (Jun 21 1992 - Jul 4 2019)METADATADATA
6Estimated biomass using measurement data and equations (Jun 21 1992 - Jul 4 2019)METADATADATA
7Assessment of 2018 burn severity (Jul 3 2019 - Jul 4 2019)METADATADATA

 Plot Layout - Schematic diagram of experimental block distribution and sample plot layout

 Pacific Northwest Plant Biomass Component Equation Library (TP072)
 Plant succession and biomass dynamics following logging and burning in Watersheds 1 and 3, Andrews Experimental Forest, 1962 to Present (TP073)

 Compagnoni, Aldo, Halpern, Charles B. 2009, Properties of native plant communities do not determine exotic success during early forest succession (Pub. No: 4437)
 Compagnoni, Aldo 2008, Controls on plant species invasions during early secondary succession: the roles of plant origin and community properties (Pub. No: 4412)
 Antos, Joseph A., Halpern, Charles B., Miller, Richard E., Cromack, Kermit, Jr., Halaj, Melora G. 2003, Temporal and spatial changes in soil carbon and nitrogen after clearcutting and burning of an old-growth Douglas-fir forest (Pub. No: 2771)
 Halpern, Charles B., Antos, Joseph A., Geyer, Melora A., Olson, Annette M. 1997, Species replacement during early secondary succession: the abrupt decline of a winter annual (Pub. No: 1890)
 Antos, Joseph A., Halpern, Charles B. 1997, Root system differences among species: implications for early successional changes in forests of western Oregon (Pub. No: 2322)
 Halpern, Charles B., Miller, Eric A., Geyer, Melora A. 1996, Equations for predicting above-ground biomass of plant species in early successional forests of the western Cascade Range, Oregon (Pub. No: 2262)