Survey of TDE Trees (> 10 cm dbh)

1.1 Document Title: TDE survey of species presence, diameter and survival.
1.2 Revision Date:  January 30, 2001
1.3 Document Summary:  Data on tree survival and diameter from 1993-1999
1.4 Sponsor: Office of Biological and Environmental Research, U. S. DOE

2.1 Investigator and data set contact:

P.J. Hanson (
Research Staff Member
Environmental Sciences Division
Oak Ridge National Laboratory
P.O. Box 2008, Building 1059
Oak Ridge, TN 37831-6422
2.2 Title Of Investigation:
Walker Branch Throughfall Displacement Experiment (TDE)

Diameter based measurements of tree dbh and visual estimates of survival for all trees (>10 cm dbh) across the TDE experimental area.

Prior to the experiment and at approximately annual intervals thereafter, all trees greater than 0.1 m in diameter at 1.3 meters (diameter at breast height; dbh) were identified to species (762 trees).  These annual diameter measurements were conducted with diameter tapes at tagged locations on all trees. Tree heights and crown widths were measured directly on approximately one third of the trees or derived from allometric relationships from a subset of the measured data.  An aerial view of the distribution of species and crown widths across the TDE are provide in the following figure.


Quercus spp. and Acer spp. were the major canopy dominants, Liriodendron tulipifera L. was a canopy dominant on the lower slope positions, and Nyssa sylvatica Marsh. and Oxydendrum arboreum [L.] D.C. were the predominant species occupying mid-canopy locations.  In March of 1994, stand basal area averaged 21 m2 ha-1 with nearly identical basal area on each plot.  By December 1999, mean basal area across all plots had increased to 22.8 m2 ha-1.

Measurements of N. sylvatica and L. tulipifera did not begin until 1994.

Data are provided in comma delimeted text files where the first line includes the variable names and subsequent lines include the following data by year.

6.1 Variable, Definition, and Units

6.2 Number of Records: 762 trees
6.3 Missing data: Missing data is represented by blank spaces in the file.
6.4 Related Data Sets:  Dendrometer based tree growth data.


8.1 Limitations of the data:     None.
8.2 Known Problems With The Data:     None.
8.3 Usage Guidance:
Trees that died during the experiment are represented by blank spaces in the years after death occurred.   Trees that reached (or approached) the 10 cm dbh cutoff during the experiment are represented by blank spaces until the year they attained tree status.


Hanson, P.J. , D.E.Todd and J.S. Amthor.   (in press)  A six year study of sapling and large-tree growth and mortality responses to natural and induced variability in precipitation and throughfall.   Tree Physiology (in press).

Hanson, P.J., D.E. Todd, M.A. Huston, J.D. Joslin, Jennifer Croker, and R. M. Augé. 1998.  Description and field performance of the Walker Branch Throughfall Displacement Experiment: 1993-1996, ORNL/TM-13586, Oak Ridge National Laboratory, Oak Ridge, Tennessee.


Click on the following to view data for the listed year.
Once open the files can exported as text files with the 'Save As' command.

Annual tree dbh data file