Welcome!
The Thinning Decision Support System is a service provided by the Texas A&M Forest Service to assist landowners and managers with determining the optimum thinning schedules and requirements for a forest stand based upon user inputs. It determines the optimum timing and timber yield for up to three thinnings and a final harvest. In addition, this Thinning DSS allows the results for up to three scenarios to be compared.
Getting Started:
Starting with the Description tab above, enter the appropriate information in the Description tab, Activities tab, and Thresholds tab for Scenario 1. If desired, click on Scenario 2 button to input different values for a second scenario on each tab. Repeat for Scenario 3, if desired. Once all inputs have be successfully entered, click on the Submit tab, review inputs, and click the Submit button at the bottom of the page to run the analysis. Click on the Results button in the left, navigation screen to review results. Results can be viewed individually for each scenario, or collectively across all scenarios.
Forest Stand Description
Prior Forest Management Activities
Thinning Decision Thresholds
Forest Stand Description
| Region: | Age: | ||
|---|---|---|---|
| Stand Type: | Density: | ||
| Species: | Site Index : | ||
| Planting stock genetic gain: | Include Site Index Adjustment: |
Prior Forest Management Activities
| Stand previously thinned: | Density before thinning: | ||
|---|---|---|---|
| Age of previous thin: | Density after thinning: |
Thinning Decision Thresholds
| Primary management objective: | Increased chance of environmental stressors?: | ||
|---|---|---|---|
| Tolerance to investment risks: | Maximum SDI: | ||
| Age at final harvest: | Adjust SDI for planting density?: |
Calculated Model Inputs
| Age: | Basal area: | ||
|---|---|---|---|
| Density: | Average height: | ||
| Site Index (base=25): | Initial Stand Density Index (SDI): | ||
| Initial diameter: | Upper limit SDI (thinning required): | ||
| Genetic gain over base: | Lower limit SDI (thinning target): | ||
| QMD where self-thinning begins: | Density dependent upper SDI limit: |
From time to time, depending upon your inputs, the optimum thinning schedule results might display a thinning age that is within two or three years of the final harvest age. This is not an error but rather important information. This knowledge provides you the opportunity to alter the final harvest age to that of the thinning age or push the desired final harvest back a few years.
| First Thin | Second Thin | |||||
|---|---|---|---|---|---|---|
| Pre-Thin Value | Post-Thin Value | Removals1 | Pre-Thin Value | Post-Thin Value | Removals1 | |
| Age (years) | ||||||
| Density (trees/acre) | ||||||
| Basal Area (sqft/acre) | ||||||
| Quadratic Mean Diameter (in) | ||||||
| Height of dominant trees (ft) | ||||||
| Stand Density Index | ||||||
| Total Stand Yield (cuft/acre) | ||||||
| Total Stand Yield (tons/acre) | ||||||
| Merchantable Yield (cuft/acre) | ||||||
| Merchantable Yield (tons/acre) | ||||||
| Third Thin | Final Harvest | Total Removals | ||||
| Pre-Thin Value | Post-Thin Value | Removals1 | Removals | |||
| Age (years) | ||||||
| Density (trees/acre) | ||||||
| Basal Area (sqft/acre) | ||||||
| Quadratic Mean Diameter (in) | ||||||
| Height of dominant trees (ft) | ||||||
| Stand Density Index | ||||||
| Total Stand Yield (cuft/acre) | ||||||
| Total Stand Yield (tons/acre) | ||||||
| Merchantable Yield (cuft/acre) | ||||||
| Merchantable Yield (tons/acre) | ||||||
| 1 Values in parentheses denote the amount removed as percent of Pre-Thin value. | ||||||
| Scenario 1 | Scenario 2 | Scenario 3 | |
|---|---|---|---|
| Stand Attributes | |||
| Initial age (years) | |||
| Initial density (trees/acre) | |||
| Site index | |||
| Previously thinned | |||
| Age at thin (years) | |||
| Density before thin (trees/acre) | |||
| Density after thin (trees/acre) | |||
| Basal area before thin (sqft/acre) | |||
| Basal area after thin (sqft/acre) | |||
| Genetic gain | |||
| Primary management objective | |||
| Tolerance to risk | |||
| Environmental stress option | |||
| Establishment density option | |||
| Age at final harvest (years) | |||
| Maximum SDI | |||
| Upper limit SDI | |||
| Lower limit SDI | |||
| First Thin | |||
| Age of thin (years) | |||
| Density before thin (trees/acre) | |||
| Density after thin (trees/acre) | |||
| Height of dominant trees (feet) | |||
| Total stand yield before thin (cuft/acre) | |||
| Total stand yield before thin (tons/acre) | |||
| Total stand yield after thin (cuft/acre) | |||
| Total stand yield after thin (tons/acre) | |||
| Yield removed during thin (cuft/acre) | |||
| Yield removed during thin (tons/acre) | |||
| Merchantable Yield before thin (cuft/acre) | |||
| Merchantable yield before thin (tons/acre) | |||
| Merchantable yield after thin (cuft/acre) | |||
| Merchantable yield after thin (tons/acre) | |||
| Merchantable yield removed during thin (cuft/acre) | |||
| Merchantable yield removed during thin (tons/acre) | |||
| Second Thin | |||
| Age of thin (years) | |||
| Density before thin (trees/acre) | |||
| Density after thin (trees/acre) | |||
| Height of dominant trees (feet) | |||
| Total stand yield before thin (cuft/acre) | |||
| Total stand yield before thin (tons/acre) | |||
| Total stand yield after thin (cuft/acre) | |||
| Total stand yield after thin (tons/acre) | |||
| Yield removed during thin (cuft/acre) | |||
| Yield removed during thin (tons/acre) | |||
| Merchantable yield before thin (cuft/acre) | |||
| Merchantable yield before thin (tons/acre) | |||
| Merchantable yield after thin (cuft/acre) | |||
| Merchantable yield after thin (tons/acre) | |||
| Merchantable yield removed during thin (cuft/acre) | |||
| Merchantable yield removed during thin (tons/acre) | |||
| Third Thin | |||
| Age of thin (years) | |||
| Density before thin (trees/acre) | |||
| Density after thin (trees/acre) | |||
| Height of dominant trees (feet) | |||
| Total stand yield before thin (cuft/acre) | |||
| Total stand yield before thin (tons/acre) | |||
| Total stand yield after thin (cuft/acre) | |||
| Total stand yield after thin (tons/acre) | |||
| Yield removed during thin (cuft/acre) | |||
| Yield removed during thin (tons/acre) | |||
| Merchantable yield before thin (cuft/acre) | |||
| Merchantable yield before thin (tons/acre) | |||
| Merchantable yield after thin (cuft/acre) | |||
| Merchantable yield after thin (tons/acre) | |||
| Merchantable yield removed during thin (cuft/acre) | |||
| Merchantable yield removed during thin (tons/acre) | |||
| Final Harvest | |||
| Age at final harvest (years) | |||
| Density at Harvest (trees/acre) | |||
| Height of dominant trees (feet) | |||
| Total stand yield (cuft/acre) | |||
| Total stand yield (tons/acre) | |||
| Merchantable yield removed during thin (cuft/acre) | |||
| Merchantable yield removed during thin (tons/acre) | |||
| Total Removals | |||
| Total harvest yield (cuft/acre) | |||
| Total harvest yield (tons/acre) | |||
| Total merchantable yield (cuft/acre) | |||
| Total merchantable yield (tons/acre) | |||