Survey of TDE Saplings (< 10 cm dbh and > 1 m tall)

1.1 Document Title: TDE survey of species presence, diameter and survival for sapling sized plants.
1.2 Revision Date:  January 30, 2001
1.3 Document Summary:  Data on sapling survival and diameter from 1996-1999
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)

Caliper measurements of sapling dbh and observations of survival for all saplings (<10 cm dbh and > 1m tall) across the TDE experimental area.

Starting in 1996 all spalings in 27 plots (8x8 m) distributed across the TDE experimental area (9 plots per treatment) were observed for survival and their diameters at marked locations on the stems.  DBH (1.3 m) was the preferred target height for diameter measurements unless the sapling was too small in which case 1 m was used instead.  The following figure shows the distribution (random within rows).  Each small block is an 8x8 m plot.

The 27 8x8 meter plots yielded a total of1728 m2 of monitored area which was 9% of the total TDE experimental area.  The number of saplings (trees < 0.1 m dbh) across the TDE area averaged 3073 ha-1 in 1994 and 2112 ha-1 in 1999.  Saplings contributed an additional 3 and 2.6 m2 ha-1 to total stand basal area in 1994 and 1999, respectively.  Acer rubrum L. and Cornus florida L. combined to make up 59 percent of all saplings and 53 percent of the sapling basal area.


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: 532 saplings
6.3 Missing data: Missing data is represented by blank spaces in the file.
6.4 Related Data Sets:  DBH data for trees > 10 cm dbh.


8.1 Limitations of the data:     None.
8.2 Known Problems With The Data:     None.
8.3 Usage Guidance:
Saplings 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 sapling dbh data file