Researchers tackled this topic examining the value and volume recovery of pine sawtimber.
Some sawmills in the U.S. South have begun purchasing prime length sawtimber processed by processors instead of, or in addition to, tree-length sawtimber produced by pull-through delimbers and slasher saws. The goal of the research was to compare volume and stumpage value recovery of two variants of the whole-tree harvesting system; being using a processor and conventional processing. The processor system used a processor on the landing to produce prime lengths while the conventional system used a loader, pull-through delimber, and slasher saw to produce tree-lengths.
Four harvest sites were split, with half of each site harvested with a processor system and the other half by a conventional system. An optimal bucking program was written to estimate theoretical stumpage value for sampled trees under tree-length and prime length specifications. Tree-length specifications resulted in slightly higher theoretical value per tree, assuming mill specifications were followed exactly.
In practice, however, processor crews producing prime lengths recovered greater stumpage value than conventional crews producing tree-lengths. Actual stumpage value of trees produced by processor crews exceeded maximum simulated values by an average of 7%, whereas conventional crews exceeded simulated values by 1%. Variation in timber utilization per hectare was high, but processor crews recovered an additional 16 t per hectare and US$ 295 per hectare relative to preharvest inventory estimates compared to conventional crews.
The research concludes that adding processors to logging crews in the U.S. South is a viable option that may increase volume and value recovery, especially when mills demand close adherence to specifications.
The research was titled “Volume and value recovery comparison of processor and conventional systems in pine stands of the U.S. South” and was published in the International Journal of Forest Engineering, 2019. The researchers were P Grove, J Conrad, and J Dahlen. Source