PERMFILE58913 - Laserfiche WebLink

Home Browse Search

-20- Revised OCT 3 0 1981 • endangered plant species of Colorado. None of these plant species proposed for threatened and endangered status was en~untered on the study area. A "vulnerable" plant species list for Colorado was obtained from the Plant Information Network (PIN), Colorado State University (CSU), Ft. Collins, Colorado. Plants listed as vulnerable are species that local taxonomists think should be monitored for possible decrease in range or number. None of the 33 "vulnerable" plant species of Colorado was encountered on the study area. TREE DENSITY AND BASAL AREA Tree density and basal area estimates are provided for species within the juniper and riparian immunities on the study area in Table 4. Density figures are to be interpreted as number of trees per unit area of the vegetation type (i.e., riparian) rather than over all types. The juniper cormiunity, oon~rised of Utah juniper (Juniperus osteosperma) wntains more trees per acre than the riparian type. The riparian tree wmrnmity, however, is more diverse ~ntaining three species of trees, narrowleaf cottonwood (POpulus angustifolia), plains cottonwood (POpulus sargentii) and Chinese elm (Ulmus parvifolia). The species containing the largest trees as deter- mined by basal area is the plains cottonwood (basal area = 900.51 csnz) followed by Utah juniper (737.10 csn2), narrowleaf cottonwood (240.77 cmz) and Chinese elm (214.26 cm2). Q7VER, FRD~UENCY, PIdDDUCPIVITY, SHRUB DENSITY AND HEIGHT Cover data are presented by species, life form and quadrat for grassland and upland sagebrush vegetation types on affected and wntrol areas in Appendix B, Part 1. Basal cover is presented for all species while canopy cover is also determined for shrub sg~cies. Percent cover estimates for bare ground and litter-rock derived from basal Dover estimates (i.e., percent ground Dover rernaining after total vegetation cover is determined is appropriated to bare ground and/or litter-rock). Shrub height data are presented for all shrubs encountered in cover quadrats. Density estimates are derived from shrub data collected in shrub density transects. A cover, shrub height and shrub density summary table for all quadrats or transects