Completion Form

2020

This treatment was designed to improve growing conditions and species composition within the residual stand and promote aspen regeneration. Trees were felled and scattered to a depth of less than 24 inches. No trees greater than 4 inches DBH were cut. Aspen was not cut, as well as any species of tree marked with orange paint for reserve.  Biomass generated from this activity in these units was salvaged by the subcontractor. The end result of this treatment was to produce a thinned spruce/fir stand to approximately 435 trees per acre (approximately 10 X 10) dominated by Engelmann spruce with a low incidence/hazard of insects and diseases.

The following thinning prescription was used for this treatment:

1)	The target spacing guideline of 435 trees per acre includes trees equal to and greater than 4 inches as well as all aspen over 4 feet in height.
2)	Thinning should proceed from the smallest diameter trees and trees below DBH. Thin "Up To" the thinning target of 435 tpa.  This should equate to a final spacing of approxinately 10 feet by 10 feet on average for Leave Trees. Live trees greater than 4 inches are to be used in determining spacing.
3)	In the event that a patch of trees exceeds 435 tpa of trees greater than 4 inches DBH, then focus and thinning sublapine-fir up to 8 inches DBH. If stocking is still too high, then focus on thinning Engelmann spruce up to 8 inches DBH to achieve final stocking.
4)	A 25 percent spacing variance (7x7 to 12x12) will be applied to allow the sawyer to select the best, most vigorus trees exhibiting good crowns and leaders. This variance will not be applied over areas greater than 0.25 acres.
5)	Cut live trees up to 4 inches DBH, do not cut any trees greater than 4 inches DBH, aspen, or trees marked with orange paint for reserve.
6)	Leave tree preference order: Aspen, Englemann spruce, other conifers.
7)	Leave trees should be of the healthiest and most vigorous. Desirable characteristics include: straight stem, good coloration, well-formed crown, free of insect and disease, crown class is dominant or co-dominant, and crown ratio greater than 50%.
8)	Do not cut any aspen.
9)	Cut trees shall be completely severed at a maximum stump height of 12 inches
10)	All live branches below stump height must be completely severed from the stump.
11)	Trees less than 1 foot in height do not need to be felled and are not part of spacing.
12)	Cut trees shall be felled to angle in a direction to protect residual trees.
13)	Buck all felled tree material to lengths of no more than 8 feet and scatter to a depth of no greater than 24 inches.

Completed 153 acres of pre-commercial thinning in conifer stands to promote aspen regeneration across three treatment units within the project area.  The average cost per acre was $923.75.  Subcontractor interest for this work was limited with multiple no-bids in the past.  NWTF has worked to increase the potential subcontractor pool for these treatments and has secured an operator to work on future treatment phases for closer to $400 per acre.  Mastication was proposed as a treatment alternative for pre-commercial thinning within these treatment units.  However, due to the project location, high mobilization cost, and dangerous stand conditions due to standing, dead trees and snags the cost per acre for mastication (~$1300/acre) was higher than pre-commercial thinning.  This cost savings resulted in the Forest Service and NWTF deciding to use the pre-commercial thinning methodology versus mastication.

There were some delays in getting these treatments completed because commercial timber removal had to be completed first.  Different operators were being used for commercial timber removal versus the pre-commercial thinning which required coordination within a very limited operating season (May/June to October/November depending on weather conditions).

Jamie Nogle

01/09/2020 13:05:28