Removal methods will consist of a combination of a cut-stump treatment (75% of trees) and a frill cut treatment (25%). Unit 1 Cut-Stump Treatment - 75% of Russian olive and Tamarisk: The cut-stump treatment will be used on 75% of the Russian olive and tamarisk. For the cut-stump treatment, tamarisk and Russian olive shall be completely severed from the stump(s). No live or dead limbs shall be left on the stump of cut trees. Stump height shall not exceed 6 inches measured on the uphill side. All main branches or stems shall be cut from the trunk of the tree to meet piling criteria. followed by cut-surface herbicide applications to prevent re-sprouting. Trees with multiple stems must have each stem treated individually. Untreated stems will survive. Appropriate PPE must be worn at all times, and great care must be taken to ensure that non-target species are not affected, and the mix is not spilled into surface waters of Castle Creek. Piling in the Nearest Open Space Biomass will be bucked into pieces no greater than 48” and piled within the open spaces. For piles: Piles should be typically be 6’x6’ but larger piles can be constructed if more practical based on pile placement constraints as long as the they can be burned without damage to cottonwoods. Piles should be placed 25-30’ from cottonwood driplines. Piling away from native shrubs is also preferred (10’) but won’t always be possible. Small tree limbs and foliage shall be placed at the bottom of the pile with larger branches placed on top and tilted around the perimeter of the pile. Piles consisting solely of large diameter vegetation (i.e. no fine fuels) shall be avoided if possible. The edge of piles shall be at least 15 feet from the edge of any other pile. In addition, the edge of piles shall be at least 15 feet from a physical improvement (such as fence or sign). If conditions make it impracticable to locate piles so that damage to the leave trees cannot be completely avoided, a space shall be cleared and all material placed on the pile in the cleared area. All natural openings shall be used before clearing a pile site. Piles will not be located within 15 feet of the unit boundary, fence, trail, or road system. Unit 1 Frill Cut Treatment - 25% of Russian olive and Tamarisk Frill cutting will be used on 25% of the Russian olive and tamarisk. USU Extension instructions for Frill Cutting are: Frill cuts are made with a hatchet or ax in the lower trunk area of the tree. Chop through the bark, into the sap wood at a slightly downward angle so the frill cut will hold the chemical. The number of frill cuts will depend on the size of the tree. One frill per inch of trunk diameter will allow 1 milliliter (1 ml) of chemical to be applied into each frill cut (1 ml = 1 cc). The frill cuts must go around the stem. However, care must be taken to not girdle the tree. Girdling severs the phloem all around the stem and stops the flow of plant food from the leaves to the roots. Staggered frill cuts will allow the tree to continue growing and move the chemical through the system.
