_INSPECTION - C1994082 (40) - Laserfiche WebLink

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September 20,2010 C-1994-082/Yoast Mine DTM with bunchgrasses and shrubs may warrant consideration. The operator has recently initiated seasonal sheep grazing within the permit area; preferential grazing of the alfalfa by sheep may speed the decline of the alfalfa, and favor the expansion of grasses and sagebrush in the alfalfa dominated stands. A large flock of sheep was grazing within the Pond 12 watershed during the inspection, and it was evident that the flock had recently grazed through the large alfalfa patches in the upper Pond 14 watershed. A number of shrub and tree planting sites have been implemented at Yoast, and SCC has cooperated with the USFS in establishing experimental plots to evaluate the effectiveness of weedguard fabric on survival and growth of planted aspen and serviceberry. Results within the various planting sites at Yoast are variable,but generally planted shrub species survival and growth has been much better in elk fenced planting sites than non fenced sites. Seeded mountain big sagebrush has established well in fenced and non-fenced planting areas,as well as many locations across the site where it was included in the upland seed mix,with a wide variety of grasses and forbs. Early results of the USFS study plots indicate dramatically improved survival and growth of aspen planted with weedguard, and corresponding though not as dramatic effect of weedguard on planted serviceberry. The fenced shrub plot designated SP07-2, located along lower YPM-10 in the North Pit area was observed during the inspection. Within the USFS study plot at the lower end of the site,the response of aspen and serviceberry to planting with and without weedguard fabric is typical of observations made at other sites: dramatically better aspen growth with weedguard; serviceberry planted with weedguard are generally taller and more robust than controls,but difference not as pronounced as with aspen. Across the remainder of the fenced planting area,it appears that there has been very low survival of planted shrubs, although there are high densities of young big sagebrush,established from seed. The site is visually dominated by early successional weedy species,though volunteer perennial grasses appear to be increasing,and seeded perennial forbs, including penstemon,blue flax, and yarrow are present in significant densities. Noxious Weeds and Cheatgrass A significant concern at Yoast, is that noxious weeds(most notably Canada thistle, whitetop, and houndstongue) exhibit a heavy presence in some reclaimed stands and disturbed sites within the permit area. Undesirable annual bromes(cheatgrass and/or Japanese brome)also are a significant problem in some areas. The operator has an approved weed management plan that addresses spraying of all of the various species of concern. During the inspection,the operator was applying Journey herbicide to a significant annual brome infestation on the south facing slopes of the PM-10 watershed,using a tractor mounted tank and sprayer. In various locations, Canada thistle patches were observed where the plants were dead from herbicide application or exhibiting symptoms from more recent spraying. However, in many locations,the weeds were robust and thriving. Given the large extent of lands that have been reclaimed in recent years,combined with growing conditions that apparently have been very favorable for Canada thistle and other weedy species,more intensive control efforts appear to be warranted. In some locations,presence of the noxious weeds and annual brome species will likely preclude Phase II or Phase III bond release until the infestations are significantly reduced. Heavy patches of the noxious and undesirable species occur in various locations throughout the disturbed area. Annual bromes seem to be most prominent on certain south facing reclaimed sites. Canada thistle and Number of Partial Inspection this Fiscal Year: 2 Number of Complete Inspections this Fiscal Year: 1 Page 6 of 13