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<br />1.0 ECOLOGICAL DESCRIPTIONS <br />1.1 PINYON/JUNIPER WOODLAND <br />Pinyon/Juniper Woodland in the Carbon Junction Mine permit area <br />exists in at least three readily identifiable phases related to substrate. <br />One phase is found on nearly bare sandstone on which vegetation exists <br />rooted in crevices and in small, shallow terraces of unconsolidated <br />material. Another phase occurs on sites where soils, although shallow <br />over sandstone and hard shales, are more or less continuous and there is <br />little massive bedrock exposed. Finally, a third phase is found on the <br />steep, coarse alluvium on the slopes in lower Carbon Junction Canyon. <br />Plant diversity in the exposed bedrock phase is relatively high <br />compared to the other phases. The diversity of microsites, the absence <br />of heavy plant competition, and the relatively low attractiveness to <br />grazers encourages a limited occurrence of a fairly large number of <br />species compared to the other phases. <br />In the bare sandstone phase the dominant plants are trees: pinyon <br />pine loinu~ edu.li a and Utah juniper fuaipe2ua o~#eoapenmo. The most <br />abundant shrubs present include Utah serviceberry Amedanchiea u#ohen~i~ <br />• and Gambel's oak (;luencua gomhe.L~i. Other shrubs present include California <br />brickel Ibush QaicheLlia ca.Li,Co.vuco, true mountain mahogany Ceacucoapu~ <br />man,tanu~, Fremont barberry Mahonia ~,¢eman,tii, squawapple %eaaphy.Llum <br />arnna~i~~imum, and shrub l ive oak (~ueacu~ #uabiae.[.Ca. <br />The major grasses present include the perennials sideoats grama <br />Qau#eCaua cuzGipendu.La, blue grama [3uu#eLaua g,¢ac.i.Li~, and Indian rice- <br />grass Oay~vp~i~ hymenaidea, and the annual, cheatgrass Ozomu~ #ectazum. <br />Minor grasses present include red threeawn A.2i~#i do .Lungiae#o, Arizona <br />fescue hea#uco o2i~an,ica, and sand dropseed Spa2oho.lun c~c~p#ond2u~. <br />The most conspicuous perennial forbs are white thoroughwort Ag.e2a#ina <br />he~Gacea, Louisiana sage Aa#emi~io .Lua'uvi u ono, and James wildbuckwheat <br />Eniatdanttm aame.~ii. Other perennial forbs present include rockcress <br />AaoGi~ sp. and beardtongue ~en.~#emaa sp. Annual forbs present include <br />small alyssum Ady~aum mirtu~, revolute spurge Chamoe.~yce aevalu#a, prairie <br />pepperweed Lepidlum den~i~Laaum, and common purslane laatu.Laco aLeaacea. <br />Additional species present along an exploration road present in the type <br />include prostrate pigweed Ama~an,thua gnaeci~an~, rough pigweed Ama~a2thu~ <br />~etico~.Cexua, dark goosefoot Cheaapadium at~ovi~en~, Canada horseweed <br />Cany~a canaden~i~, flixweed tansymusTard Deacuaain,ia aaphia, and Dakota <br />verbena Verbena bipinaa#i,Cido. Total plant cover in this phase of the <br />Pinyon/Juniper Woodland is estimated to be between 20 and 30 percent. <br />In the Pinyon/Juniper Woodland phase on shallow but continuous soils, <br />the tree canopy is much better developed, resulting in an estimated total <br />plant cover of 60 to 70 percent. Pinyon pine and Utah juniper reach <br />• heights of 7 m in some parts of These stands. The extensive tree canopy <br />cover land doubtless equally extensive roots) results in a strong suppression <br />-1- <br />