1. Tree List Generator (TLG) v1.0
Kevin R. Gehringer
Eric C. Turnblom
15 September 2003
SMC Fall Policy Committee Mtg.

2. SMC Fall Policy Committee Mtg.
TLG - Topics
Introduction / background
Models / Methods
Results / Discussion
Operation / Output
Future work / conclude
15 September 2003
SMC Fall Policy Committee Mtg.

3. SMC Fall Policy Committee Mtg.
TLG - Introduction
Initial tree list estimation for individual tree based growth models
Basically targeted use of the SMC-ORGANON modeling database to develop a methodology for generating initial tree lists
Tree List Generation Database software provides a means for producing reasonable tree lists for a forest stand based on a minimal amount of information, such as SI, age, TPA, etc.
15 September 2003
SMC Fall Policy Committee Mtg.

4. SMC Fall Policy Committee Mtg.
TLG - Introduction (2)
Tree list is a compatible set of DBH and height measurements for each tree as well as species
TLG is designed for managed, mixed species stands of Douglas-fir and western hemlock as dominant species (with mixtures of other minor species)
Untreated stands and thinned stands throughout southwestern British Columbia, Washington and Oregon west of the Cascade Crest
15 September 2003
SMC Fall Policy Committee Mtg.

5. SMC Fall Policy Committee Mtg.
TLG - Introduction (3)
Tree list generation requires four things:
A method for classifying stands
A method for selecting an appropriate stand class
A method for generating a tree list from a stand class
A wide variety of stand measurement data sets
Useful to think under the framework of generating a random stand of trees using a small set of stand attributes as the “seed”
Several ways to define and implement the first three requirements…
15 September 2003
SMC Fall Policy Committee Mtg.

6. SMC Fall Policy Committee Mtg.
TLG - Methods
Weibull density distribution based methods
Weibull is strongly unimodal
Represents flat distributions poorly
Mixed species stands present challenges
Parameter prediction functions may change with new data
Non-parametric, density estimation methods (e.g., B-splines, etc.)
15 September 2003
SMC Fall Policy Committee Mtg.

7. SMC Fall Policy Committee Mtg.
TLG - Methods (2)
Tree List Generation Database method
Explicit classification based on a multidimensional histogram (data “speaks for itself”)
Histogram is a consistent estimator of a density function
Histogram allows refinement of its classification if sufficient data warrant higher resolution
Histogram does not require reevaluation of classification rules when new data is added
Histogram dimensions are stand attributes, e.g., site index, QMD, stand type, etc
15 September 2003
SMC Fall Policy Committee Mtg.

8. SMC Fall Policy Committee Mtg.
TLG - Methods (3)
Tree List Generation Database method (cont’d)
Stands with similar attributes belong to same hist. Bin
Given a set of desired stand attributes, similarity scores are calculated for stands defined by the tree list generation database
The “k” smallest similarity scores are used to select the collection of stands to form the canonical stand from which a tree list may be generated
15 September 2003
SMC Fall Policy Committee Mtg.

9. SMC Fall Policy Committee Mtg.
TLG - Methods (4)
Two fundamental assumptions
Forest stands, or sample plots, having similar attributes, e.g., site index, QMD, species composition, etc., are similar
Attributes of forest inventory data collected from a representative set of sample plots from within a larger stand may be extended to the whole stand
15 September 2003
SMC Fall Policy Committee Mtg.

10. SMC Fall Policy Committee Mtg.
TLG - Results
Simulated stands generally agreed with the actual stands they were generated to mimic at the individual tree level defined by DBH, height and species
Based on a single random “draw”
For DBH alone, misclassification rate was 2.6%
For height, misclassification rate was 13.2%
For species comp., misclassification was 8.3%
15 September 2003
SMC Fall Policy Committee Mtg.

11. SMC Fall Policy Committee Mtg.
TLG - Operation
Conventional “DOS” command line interface
Stand Description files specify input values for the set of measured or desired attributes used as the histogram bin dimensions for which a simulated tree list is desired
comments appear after a “%” sign
“KEYWORD = VALUE” format defines desired attributes
15 September 2003
SMC Fall Policy Committee Mtg.

12. SMC Fall Policy Committee Mtg.
TLG - Operation
% Example stand description file
TREATMENT_TYPE = UNTREATED
SITE_INDEX = 140.0
STAND_TOTAL_AGE = 57.0
STAND_ORIGIN = NATURAL
STAND_DENSITY = 160.0
QMD = 12.6
STAND_TYPE = PURE_DF
15 September 2003
SMC Fall Policy Committee Mtg.

13. SMC Fall Policy Committee Mtg.
TLG - Operation
Random Measurement files are produced by the tree list generation process and contain attributes for the stand and a simulated stand of trees
Three files are needed to set up or change the stand classification attributes
Schema file: defines multidimensional histogram bin dimensions
Species mapping file: maps 2-6 char. Code to integer
Stand measurement file: added to tree database
15 September 2003
SMC Fall Policy Committee Mtg.

14. SMC Fall Policy Committee Mtg.
TLG - Future work
Add new Type I and Type III data to the set of stand measurement files included in the tree list generation database distribution set
Add Graphical User Interface (GUI) such as is used with DFSIM, that is, DFSIMIN
15 September 2003
SMC Fall Policy Committee Mtg.

15. SMC Fall Policy Committee Mtg.
TLG - Possible GUI
15 September 2003
SMC Fall Policy Committee Mtg.

16. SMC Fall Policy Committee Mtg.
Tree List Generator
Please visit <
Click on the SOFTWARE link on L.H.S.
Questions / Comments ?
Kevin R. Gehringer
Eric C. Turnblom
15 September 2003
SMC Fall Policy Committee Mtg.