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operator due to stand failure within the field trial areas will not reinitiate the bond liability
<br />period.
<br />In 2006 under MR-83, Colowyo initiated a buried topsoil protocol to try an increase
<br />establishment of shrubs on the mine-site. Two, two acres test plots were topsoiled and then
<br />covered with six inches of "benign", nutrient-poor overburden in the attempt to slow or delay
<br />emergence and growth by competing grasses and annual weeds, thereby allowing shrub seed
<br />additional time to break dormancy and emerge. Prior to seeding taking place one composite
<br />sample was taken from each test plot. The constituents analyzed were texture, fetility, pH,
<br />percent coarse fragments, electrical conductivity, sodium adsorption ratio, selenium, and
<br />boron. To further encourage shrubs growth, the seed mix was heavily weighted toward
<br />shrubs. The seed mixture that was used on the test plots is shown below.
<br />Seed Mix -Buried Topsoil Test Plot Seed Mix - Colowyo Mine - 2006
<br /> ecommen s
<br /> Species Synonym Common Name Seeds/ Ib. lbs. /acre sq. foot
<br /> Agropyron dasys(achyum Etymus/anceo/atusssp. /anceo/atus Thickspike Wheatgrass 154,000 0.25 0.88
<br /> Agropyron smithii Pascopyrum smithi/ Wes[ern Wheatgrass 110,000 0.25 0.63
<br /> Agropyron spicatum inemre Pseudoroegneria spicata ssp. inerme Beardless Bluebunch Wheatgrass 117,000 0.50 1.34
<br />~ Agropyron tYdchycau/um E/ymus trachycau/us ssp. frachyrau/us Slender Wheatgrass 159,000 0.50 1.83
<br /> Poa Ampla Big Bluegrass 882,000 0.10 2.02
<br /> Subbotal = 1.60 6.71
<br /> Achi//ea mi//ifo/ium Western Yarrow 2,770,000 0.10 6.36
<br />~„ Artemisia /udoviciana Louisiana Sagewort 33,600 0.75 0.58
<br />v Asterchilensis Vrgu/aslerascerMens PadficASter 2,668,000 0.10 6.12
<br /> Cinum /ewisii Lewis Flax 293,000 0.20 1.35
<br />~° Artemisia fiidgida Fringed Sage 4,536,000 0.05 5.21
<br /> Penslemon striclus Rocky Mountain Penstemon 592,000 0.20 2.72
<br /> Subtotal = 1.40 22.33
<br /> Ame/anchiera/nifo/ia Saskatoon Serviceberry 25,800 1.50 O.B9
<br /> Artemisa bidentata rese}ana Mountain Big Sagebrush 2,500,000 0.25 14.35
<br /> Artemisia Cana Silver Sagebrush 850,000 0.75 14.63
<br />~
<br />g Adip/ex canescens Fourwing Saltbush 52,000 1.00 1.19
<br />,°e Ceratoides/anatd Wiinterfat 56,700 2.00 2.60
<br />m Chryso[hamnus nauseosus Rubber Rabbitbrush 400,000 0.50 4.59
<br /> Purshla tridentate Bitterbrush 15,000 3.00 1.03
<br /> Rosa woodsii Wood's Rose 45,300 1.50 1.56
<br /> Symphorrcarposrolundifo/iius Mountain5nowberry 75,000 1.50 2.58
<br /> Subtotal = 12.00 43.44
<br /> Total 15.00 72.48
<br />At the peak of each subsequent growing season, or shortly thereafter, for a period of at least 5
<br />years, these test plots will be evaluated for emergent shrub density, ground cover by species,
<br />and a visual evaluation of surficial erosion. This data will be reported annually in the Annual
<br />Reclamation Report. If data shows that there is promise as a shrub conducive reclamation
<br />procedure, CDMG may be contacted to initiate alternate reclamation procedures for the
<br />remainder of Colowyo reclamation.
<br />4.15.7 Determining Revel;etation Success: General Requirements and Standards
<br />During the summer of 1980, two reference areas were selected to represent the two major
<br />vegetative communities to be disturbed, sagebrush and mountain shrub. The location of the
<br />reference areas are shown on the Vegetation map (Map 4) and Regional Vegetation map
<br />(Map 3). Extensive, detailed vegetative sampling was performed, duplicating the
<br />methodologies as described in Section 2.04.10.
<br />4.15-9 Revision Date: 10/3/06
<br />Revision No: MR-83
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