2007-10-26_REVISION - M1980110 - Laserfiche WebLink

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6,4.]0 Exhibit J -Vegetation Information 1 (a) Vegetation Description Savage and Savage conducted a vegetation assessment for the proposed Hall-Trwin Long Resou~e site on May 7, 2007. Weather during the site investigation was breezy, dry, and overcas3 with temperatures In the mid 70's. The vegetation of the majority of the site has been historically altered from native conditions through agriculture, grazing, and development of residential concerns. There are no significant native vegetation communities extant on the two parcels comprising the project site. Both parcels contain vegetation that can be categorized as mesic/xeric introduced ruderal herbaceous seral. The visually dominant species include cheatgrass (Bromus tectorum) an introduced annual grass, musk thistle (Ctrsium arvense) a state listed noxious weed, annual mustards (Descurainia species), and curly dock (Rumex crispus), a native early seral stage invader forb. With the exception of the azea immediately surrounding the homestead there is no developed tree or shrub overstory or understory. Within the primary alluvial terrace at the southern boundary of the project site, small inclusions (<2 acres total) of native wet meadow are present. The dominant vegetation of these inclusions includes Baltic rush (Juncos balticus), Nebraska sedge (Carex nebraskensis), inland saltgrass (Distichlis spicata), clover (Trifolium repens), and orchardgrass (Dactylis glomerata). Total vegetation cover of the ruderal mesic vegetation community was estimated at 50 percent, and the average height of the dominant species was 0.4 meters. Vegetation cover within the wet meadow inclusions was estimated at 70 percent with an average vegetation height of 0.2 meters. There was no evidence of any listed or candidate ptant species of special concern. 1 (b) Relationship to Soils There is a significant correlation between the vegetation currently on the parcels and the soils of the project site. The areas planted to agricultural row crops and the mesic ruderal plant community are located above the primary alluvial terrace and have loamy soils formed from aeolian and outwash pazent materials (Kim, Olney, and Otero soil series}. The primary alluvial terrace area, restricted to the southeast portion of the project site contains aquoll and aquent soils that are derived from alluvial deposition. Where native vegetation inclusions aze present, and the hydrology has not been changed through subsequent uses, the wet meadow plant species are present in the small inclusion. 1(c) Carrying Capacity The MRCS (USDA, 1980) lists ranges of herbaceous native vegetation production for the soil map units found in the project site as follows.