- Thinning Specifications: o Conifers less than 8 inches Diameter Breast Height (DBH) will be spaced leaving 10-15 feet between crowns, or 10-15 feet between stems in stands of trees less than 10 feet tall. o Remove dead or dying oak stems that are less than 4 inches DBH underneath canopy of larger trees. o All trees less than 8 inches DBH will be removed within 5 feet of the road edge and masticated or chipped based on Units listed above, unless leave trees otherwise predesignated or agreed to in writing by the DNR Project Manager or designee. o Species Selection criteria: Priority will be placed on retaining 1. Oregon White Oak, 2. Ponderosa pine, 3. Douglas fir. Remove Grand fir when other species are present. o Remove all trees less than 8 inches DBH growing within the drip-lines of overstory conifers, or where tree crowns overlap. o Trees with poor growth form and less than 30% live crown ratio should be targeted for removal. o Trees with a Hawksworth dwarf mistletoe rating of 4 or greater will be targeted for removal if 8 inches in diameter or less. - Pruning Specifications o No pruning is required on trees less than 6 feet tall. o All live limbs on conifers will be pruned by hand up to a height of 10 feet, or 30% of the tree height, whichever is shorter. On oak trees, prune dead, dying and branches physically touching the ground ONLY. o Proper pruning techniques will be used to minimize damage to tree boles. Limbs will be pruned at the branch collar. o Cut limbs will be masticated or chipped on site and spread evenly across the treatment area. - Brush Control Specifications o All brush will be removed within 10 feet of the driplines of leave tree canopies, and within 15 feet on the downhill side. o All brush will be cut and chipped or masticated on site unless leave areas are predesignated or agreed to in writing by the DNR Project Manager or designee. o If Himalayan blackberry bushes are present, the bush should be targeted for removal. o The height of any remaining brush should not exceed 4 inches. - Slash Disposal Specifications o Chips will be dispersed evenly over the site, not to exceed a depth greater than 4 inches, unless the DNR Project Manager or their designee specifically states in writing otherwise. o Dead and down material up to 10 inches in diameter will be chipped or masticated and the material scattered over the work site. o The limbs of dead and down trees will be removed and chipped or masticated and the remaining trunk will be left in place unless several trees have created a piled concentration. In this case, the remaining trunks will be separated by at least 10 feet from any other logs and left on site. o Chipping and mastication mean grinding, shredding, chopping, cutting, or breaking of trees, logs, slash, and vegetative material to no greater than 4” x 4” x 12”. Ninety percent (90%) of this material must be no larger than the stated dimensions, and 100% must be below 6” x 6” x 24” in size. - Standing dead trees that pose a hazard to workers or are within 1.5 tree lengths of roads or structures shall be felled and treated using the slash disposal specifications regardless of size. - Standing dead trees with red needles shall be felled and treated using the slash disposal specifications. Contact DNR Project Manager or their designee for approval before felling of trees over 8-inch diameter. - Standing dead trees less than 8” DBH shall be felled and treated using the slash disposal specifications. - The Contractor will not cut any green trees from the premises that are greater than 8-inch diameter at breast height without prior written approval from the DNR Project Manager or their designee. - Cut stump heights for all vegetation will be made as close to the ground as possible, not to extend more than 4 inches above closest terrain. Flat cuts will be made so that it does not create a sharp stump. - Ground disturbance from equipment shall not cause ruts or berms greater than 4 inches as measured from the natural ground line. Operator-caused ground disturbance will be smoothed out to original contours before leaving the immediate work area.
