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,~ where: xfeV =Average vegetation cover for revegetated area' ~ .~
<br />" ; Aa =Aspen type acreage, 'premining surface area -
<br />.' ~ Ab =.Mixed brush type acreage, premining surface area ~, ~ ~ _ '
<br />' ~ ~ - ~ ~ AS =Sagebrush type acreage, premining surface area
<br />A,,,r~,y =Western wheatgrass/alkali sagebrush type acreage; premining surface
<br />area. '
<br />~~ ~ ~~ xa~, =Average. reference area herbaceous cover -aspen type
<br />-,. .'zb =Average reference area herbaceous cover =mixed brush type
<br />~' .~ ~ xs ~= Average reference area herbaceous cover-sagebrush type ~~
<br />,.~ ~ x,,,~,,,r •= Average reference area herbaceous cover-western wheatgrass/alkali ~ '
<br />sagebrush type ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ '
<br />At = ~TOtal of relative community type acreages; premining surface area:. '
<br />• '
<br />-. For the II-W South Extension "Area; the cover standard willbe calculated tiased on the extent
<br />' of herbaceous gover in fiveERA vegeation types.Included:in theaverage will be data from
<br />.the Aspen. Woodland, Mountain. Brush,. Steep Mountain Brush, Sagebrush/Snowberry, and ,
<br />Western Wheatgrass/Alkali Sagebrush vegetation types. .The extent.of herbaceous cover in .
<br />-each of these types will be represented by the "all-hit" measure of.~cover in which the full
<br />' extent of a species cover, whether overlapped by the canopy of. another ,~or. not is
<br />'.ihdependently assessed. For an example of this source ,of~.cover information, see the cover
<br />" tables associated with the baseline.vegetatiori :sampling reported, in Tab .10. Although the
<br />' development 'of trunks, branches, twigs, and leaves ~of ~shrubs~and trees overarches fairly
<br />extensive areas in several of the vegeation types, the .herbaceous :cdmponent is 'still quite
<br />•. extensive in most, though often in the shade of the woody species. 'For example, in the Aspen ~.
<br />'~Woodland.ERA of the II-W South Extension Area,.herbaceous cover. based 'on all=hit data is
<br />90.1 percent. An average of the herbaceous cover of the, ERA types,'weighted by .their extent.
<br />in the permining area, would be calculated using the formula stated above for the II-W area, ~.
<br />'~~. but using "all-hit" data rather than "first hit" data as was done there. ~, ~'
<br />xrev' `, 0.90 11Aa1 Ixal + IAbllxbl +~ IAsbl lxsbl' + IAsllxsl + (Awwl Ixwwll ~ ;
<br />where the symbols are used as specified.above and: ~- " . -
<br />A„= Steep Mountain Brush type acreage, premining surface ,
<br />Xae= Average reference area herbaceous cover -.steep mountain brush type ~ ~ ~ , "
<br />~,~ For example, based-on thesampling of the II-W South Extension Area during the baseline year,
<br />.t Fie following data would be used:. _ ~ , .~
<br />40 ~. ~ ~ ~ Revised 1 /99
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