Procedure or system: Methods used to reduce damage to selected trees while the harvester is working.
| Area | Description |
|---|---|
| Problem | Excessive damage to retained trees, mostly caused by the harvester bumping or scuffing the trees while it is working. |
| People consulted | Harvesting operators – to talk about the problem and proposed solutions. Forwarder operators – to get their perspective on the problem and proposed solutions. Supervising Forest Officer – to discuss reports and ask for suggested remedies. |
| Documents consulted | Harvesting plan for the coupe. Commercial thinning operations in native regrowth and plantation eucalypt forests – a manual of best practice (2007) Mike Connell. Timber Harvesting in Forests NSW Plantations (2005) Forests NSW. |
| Solution | Leave more 'guard' trees in place while the harvester is removing and processing thinnings. The guard trees would shield the retained trees from impacts with the harvester itself and the trees being felled. Once the processing is completed, remove the guard trees. |
| Goal (target) | To reduce the amount of damage to retained trees by two percentage points. That is, if the average damage in a particular area runs at 12%, we would try to reduce it to 10%. |
| Area | Description |
|---|---|
| Actions | The harvester operator and I walked through a small area that was about to be thinned. We marked the selected (retained) trees and chose the best placed 'guard' trees that would protect the selected trees while the thinnings were being felled and processed. The operator thinned the area and then we walked through it again before he removed the guard trees to inspect the selected trees for damage. |
| People involved | Harvesting operator and self. |
| Documents used | Harvesting plan. |
| Area | Description |
|---|---|
| Monitoring techniques | Observation – to look for scuffing and impact damage in the selected trees and assess the percentage of damage caused by scuffing or harvester impact. Also to evaluate the positioning of the guard trees and decide whether they had been the best placed trees to minimise damage to the selected trees. Verbal discussion – with the harvester operator to talk about the results and any problems he was having. Statistical calculations – of the percentage of damage to selected trees, to see if there was a noticeable improvement in the average figures being achieved for that type of terrain and species make-up. |
| Findings | There appeared to be a slight reduction in the amount of damage being sustained by the selected trees. However, we considered the test area to be too small to really be able to tell. Nonetheless, the result was promising enough to continue to roll out the plan of leaving more guard trees in place while thinning. Although this would mean that it would take a bit longer to thin the bays, we considered that it was worth the extra effort. |
| People involved | Harvesting operator and self. |
| Documents used | Harvesting plan. Audit report of thinned area. |
| Area | Description |
|---|---|
| Actions | The harvester operator continued to choose guard trees in the way we had trialled. Once he got more used to judging where the best-placed guard trees were, we stopped marking them beforehand and he made the decisions while he was working. |
| Monitoring techniques | Observation – to look for scuffing and impact damage in the selected trees. Verbal discussion – with the harvester operator and the supervising forest officer. Statistical calculations – of the percentage of damage to selected trees. |
| People involved | Harvesting operator, supervising forest officer and self. |
| Documents used | Harvesting plan. Audit report of thinned area. |