2016-12-23_PERMIT FILE - C1982056A (8)

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Sagebrush habitats in the permit area were delineated and mapped as three distinct sagebrush communities: low sagebrush, mountain (big) sagebrush, and sagebrush/meadow. Locations and extent of these communities are plotted on Map 22, Locations of Sage Grouse Leks and Sagebrush Habitat. Low sagebrush is the predominant • sagebrush community occurring in the permit area. It occurs throughout the lowland portions of the permit area where cultivation has not occurred. Mountain sagebrush occurs as small inclusions within low sagebrush and on steeper slopes at higher elevations. Sagebrush/meadow is found only along bottomland portions of Fish Creek and Foidel Creek. Cover and height measurements and observations on dominant and subdominant understory species were made in the field in representative stands of each sagebrush community. Cover estimates were made using a 100 -foot, line - intercept transect. Transects were randomly placed in each major sagebrush community, and the amount of sagebrush coverage along each line was measured. Average heights of representative stands was determined by taking height measurements at random points within each stand. The total number of cover transects and height measurements was determined, to a certain extent, by the extent of each community occurring within the permit area. The total number of height measurements and cover transects implemented is given below. Cover Transects Height Measurements Low Sagebrush 14 120 Mountain Sagebrush 11 75 Sagebrush/meadow 5 20 Snow depth measurements were not made in the sagebrush communities since qualitative observations (monthly aerial surveys 1980 -84) indicate, that in most winters, sagebrush communities within the permit area in Twentymile Park are totally covered by snow. It was inferred from this information that few sage grouse winter in sagebrush communities within the permit area in Twentymile Park. A summary of cover and height measurements made in the three sagebrush communities within the proposed •permit area is presented on Table 43, Sagebrush Height and Cover. On the average, low sagebrush communities are considerably shorter but exhibit greater sagebrush canopy cover than mountain sagebrush and sagebrush/meadow. Sagebrush/meadow exhibits the lowest sagebrush canopy cover of the three types. The dominant shrub in sagebrush/meadow is silver sagebrush, while in low sagebrush and mountain sagebrush the dominant shrub is low sagebrush and big sagebrush, respectively. Common understory species in mountain and low sagebrush are big bluegrass, slender wheatgrass, mulesears wyethia, yarrow and lupine. In sagebrush/meadow, Kentucky bluegrass, Baltic rush, sedges, yarrow, Canada thistle (Cirsium arvense), and new Mexican checkermallow (Sidalc:ea neomexicana) are predominant understory species. In quantitative sampling conducted for the vegetation information presented in this permit application (see Rule 2.04.10 Response), forb production and percent cover in the low and mountain sagebrush types (combined) were 22.6 g /m2 and 16.8 percent, respectively. Forb production and percent cover in sagebrush/meadow were 37.9 g /m2 and 14.9 percent, respectively. Qualitative observations in the low and mountain sagebrush communities indicated that in areas where sagebrush canopy cover approached 50 percent, understory forbs and grasses were considerably reduced. Based on previous studies and qualitative observations and quantitative measurements of sagebrush communities in the permit area, certain assumptions can be made regarding sage grouse utilization of these communities. Open areas of low sagebrush are potentially important as breeding grounds. Sagebrush canopy measured on the Twentymile Lek was 10.2 percent, the lowest value obtained in the low sagebrush community. Nearly all researchers have reported that sage grouse prefer open areas surrounded by low sagebrush as strutting grounds (Patterson 1952, Rodgers 1694, Gill 1965, Wallestad 1975), although there is some use of other open areas such as hay meadows (Rodgers 1964). Open, low sagebrush areas are also preferred by broods for feeding on insects and forbs. Initially sage grouse chicks are heavily dependent on insects, but as they grow older (by 12 weeks of age) their diet is dominated by forbs (Klebenow and Gray 1968, Peterson 1970). Habitats utilized by broods shift from low sagebrush to meadows and back to sagebrush as summer progresses (Gill 1965, Wallestad 1971). Broods have also been shown to move up in elevation as the summer progresses and as green food plants dry up at the lower elevations (Klebenow 1969). Wallestad (1971) and Martin (1970) found that the majority of broods located in early summer were in areas with RN08 -05 2.04 -64 03/12/10