Griffiths, R. 2011. Influence of tree-fall gaps on soil characteristics in gaps of varying sizes in the Andrews Experimental Forest, 1995 Long-Term Ecological Research Andrews Forest LTER Site. [Database]. Available: https://andrewsforest-stage.forestry.oregonstate.edu/data/fsdb-data-catalog/SP017 Accessed 2026-05-10.

This is the first of three tree-fall gap studies conducted at the H.J. Andrews Experimental Forest addressing the effects of tree-fall gaps on forest soil characteristics. The second (Gap2) compared the effects of gaps on soil properties along both N-S and E-W transects to better differentiate between microclimate and vegetation effects within gaps. The final study (Gap3) expanded the number of variables studied and sampling intensity. By using the same grid system as Dr. Andy Gray in his vegetation survey work, the Gap3 study provided the most definitive connection between above-ground vegetation and associated below-ground processes. Soil properties in 10, 20, 30, and 50 meter tree-fall gaps were compared with soils in the surrounding old-growth Douglas-fir forest by sampling at 1 meter intervals along transects running north and south through the gaps. These transects extended one radius into the surrounding forest. This study was designed to determine if carbon cycling within these gaps were different from those in the soils of surrounding undisturbed forests. If there were differences, she wanted to determine what sized gap was required to show an effect. These transects were divided into four zones. Two zones were north of the E-W centerline; one in and one out of the gap. The other two zones were south of the E-W centerline; one in and one out of the gap.

Temporal coverage: 1995-01-07 to 1995-01-08

Geographic coverage: N/A

Bounds: W N/A, E N/A, N N/A, S N/A

• Tree-fall gaps are known to play an important role in the formation and maintenance of old-growth forest structure and forest biodiversity. Prior research has focused on above-ground vegetative succession and population dynamics and little is known about changes occurring below-ground as vegetation becomes reestablished. The interplay between gap microclimatic gradients and both vegetation and the below-ground component of the ecosystem is potentially complex. Thus to understand how gaps influence forest floor carbon cycling, one must consider both above and below-ground components.
• Soil moisture and temperature were both higher in the gap than in the surrounding forest but SOM, lab respiration and litter depth were both lower in the gap than in the forest. These results suggest that either litter input is lower in the gap than in the surrounding forest and/or that the decomposition rates are lower in the gap. Except for the smallest gap, soil moisture was lower and temperature higher in the northern half of the gap. In the 50 m gaps, laboratory respiration rates, litter depth, and soil organic matter (SOM) were higher in the southern portion of the gap as were total carbon values.

Title: Long-Term Ecological Research

• Robert P. Griffiths
  Role: Principal Investigator
  Oregon State University;Dept. of Forest Science;321 Richardson Hall, Corvallis, OR, 97331-5752, USA
  Phone: (541) 737-6559
  Email: bbgriff@peak.org, griff@for.orst.edu
• Robert P. Griffiths
  Role: Abstractor
  Oregon State University;Dept. of Forest Science;321 Richardson Hall, Corvallis, OR, 97331-5752, USA
  Phone: (541) 737-6559
  Email: bbgriff@peak.org, griff@for.orst.edu
• Robert P. Griffiths
  Role: Creator
  Oregon State University;Dept. of Forest Science;321 Richardson Hall, Corvallis, OR, 97331-5752, USA
  Phone: (541) 737-6559
  Email: bbgriff@peak.org, griff@for.orst.edu

• Information Manager
  Andrews Forest LTER Program, US Forest Service Pacific Northwest Research Station, 3200 SW Jefferson Way, Corvallis, OR, 97331
  Email: hjaweb@fsl.orst.edu
  URL: http://andrewsforest.oregonstate.edu/
• Robert P. Griffiths
  Oregon State University;Dept. of Forest Science;321 Richardson Hall, Corvallis, OR, 97331-5752, USA
  Phone: (541) 737-6559
  Email: bbgriff@peak.org, griff@for.orst.edu

• Andrews Forest LTER Site
  Role: Publisher
  Forest Ecosystems and Society Department in Forestry, Oregon State University, 201K Richardson Hall, Corvallis, OR, 97331-5752
  Phone: (541) 737-8480
  Email: lterweb@fsl.orst.edu
  URL: http://andrewsforest.oregonstate.edu/

This is the first of three tree-fall gap studies conducted at the H.J. Andrews Experimental Forest addressing the effects of tree-fall gaps on forest soil characteristics. The second (Gap2) compared the effects of gaps on soil properties along both N-S and E-W transects to better differentiate between microclimate and vegetation effects within gaps. The final study (Gap3) expanded the number of variables studied and sampling intensity. By using the same grid system as Dr. Andy Gray in his vegetation survey work, the Gap3 study provided the most definitive connection between above-ground vegetation and associated below-ground processes. Soil properties in 10, 20, 30, and 50 meter tree-fall gaps were compared with soils in the surrounding old-growth Douglas-fir forest by sampling at 1 meter intervals along transects running north and south through the gaps. These transects extended one radius into the surrounding forest. This study was designed to determine if carbon cycling within these gaps were different from those in the soils of surrounding undisturbed forests. If there were differences, she wanted to determine what sized gap was required to show an effect. These transects were divided into four zones. Two zones were north of the E-W centerline; one in and one out of the gap. The other two zones were south of the E-W centerline; one in and one out of the gap. Tree-fall gaps are known to play an important role in the formation and maintenance of old-growth forest structure and forest biodiversity. Prior research has focused on above-ground vegetative succession and population dynamics and little is known about changes occurring below-ground as vegetation becomes reestablished. The interplay between gap microclimatic gradients and both vegetation and the below-ground component of the ecosystem is potentially complex. Thus to understand how gaps influence forest floor carbon cycling, one must consider both above and below-ground components. Field Methods - SP017

Purpose: Tree-fall gaps are known to play an important role in the formation and maintenance of old-growth forest structure and forest biodiversity. Prior research has focused on above-ground vegetative succession and population dynamics and little is known about changes occurring below-ground as vegetation becomes reestablished. The interplay between gap microclimatic gradients and both vegetation and the below-ground component of the ecosystem is potentially complex. Thus to understand how gaps influence forest floor carbon cycling, one must consider both above and below-ground components.

Method Steps

Sampling

No software entries listed in this EML file.

• LTER controlled vocabulary: disturbance (theme), inorganic nutrients (theme), soil (theme), forests (theme), canopy gaps (theme)
• Andrews Experimental Forest site thesaurus: Long-Term Ecological Research (LTER) (theme)
• LTER core research areas: disturbance (theme), inorganic nutrients (theme)

No taxonomic hierarchy listed in this EML file.

• TV025

No publication citations found in this EML file.

No related files listed in this EML file.

Data Use Agreement:

The re-use of scientific data has the potential to greatly increase communication, collaboration and synthesis within and among disciplines, and thus is fostered, supported and encouraged. This Data Set is released under the Creative Commons license CC BY "Attribution" (see: https://creativecommons.org/licenses/by/4.0/). Creative Commons license CC BY - Attribution is a license that allows others to distribute, remix, tweak, and build upon your work (even commercially), as long as you are credited for the original creation. This license accommodates maximum dissemination and use of licensed materials.

It is considered professional conduct and an ethical obligation to acknowledge the work of other scientists. The Data User is asked to provide attribution of the original work if this data package is shared in whole or by individual parts or used in the derivation of other products. A recommended citation is provided for each Data Set in the Andrews LTER data catalog (see: http://andlter.forestry.oregonstate.edu/data/catalog/datacatalog.aspx). A generic citation is also provided for this Data Set on the website https://portal.edirepository.org in the summary metadata page. Data Users are thus strongly encouraged to consider consultation, collaboration and/or co-authorship with the Data Set Creator.

While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed and all data are made available "as is." The Data User should be aware, however, that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data.

General acknowledgement: 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. If data used in publication, Robert Griffiths and Shirley King will be listed as a coauthor. Whenever these data are presented in whatever form, Griffiths and King will be acknowledged.

License: N/A

Maintenance update frequency: irregular

Description

• An update history is logged and maintained with each new version of every dataset.

Change History

• Version1 (2001-05-02)
  Original metadata creation.
• Version2 (2002-02-08)
  Metadata restructured and moved into SQLServer metadata database LTERMETA. Data moved into SQLServer database FSDBDATA.