2019-05-14_PERMIT FILE - M2019025 (16)

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ATTACHMENT D Mature cottonwood gallery forest lines the Big Thompson River and the western portion of the Hill and Brush Ditch on the Coulson parcel (Photo 4). However, there are few trees on the eastern Croissant Farms parcel (Figure 2). The pasture areas are dominated by introduced grasses and weeds including quackgrass (Elytrigio repens), Canada bluegrass (Poo compresses), and intermediate wheatgrass (Thinopyrum intermedium) (Photo 5). 3.0 LITE LADIES' TRESSES ORCHID HABITAT CHARACTERISTICS The Ute ladies' tresses is a federally listed Threatened perennial, terrestrial orchid endemic to moist soils in mesic or wet meadows near springs, lakes, or perennial streams (USFWS, 1995; Jennings, 1990). In Colorado, the elevational range of known orchid populations is between 4,500 and 6,800 feet (Spackman et al., 1997). The orchid prefers sites with permanent sub- irrigation such as floodplains where the water table is near the surface throughout the growing season and into the late summer or early autumn (USFWS, 1995; Jennings, 1990). The current distribution of Ute ladies' tresses orchid includes populations in Colorado, Wyoming, Nebraska, Utah, Idaho, Montana, and Nevada (CNHP, 2018). Colorado supports populations of the Ute ladies' tresses orchid in relict tallgrass prairie and irrigated pastures near South Boulder Creek in Boulder County, and in mesic meadows in the riparian woodland understory along Clear Creek in Jefferson County. The South Boulder Creek population represents one of the largest known occurrences of the orchid. Smaller populations have been identified adjacent to St. Vrain Creek near Hygiene in Boulder County and near the Cache La Poudre River at the northwest edge of Fort Collins in Weld County, Colorado. Historic collections from Colorado were made in 1856 from the South Platte River and in 1896 from Camp Harding near Colorado Springs in El Paso County. The Ute ladies' tresses orchid is relatively intolerant of competition, and is found primarily in communities where the vegetation is open and not overly dense or overgrown (USFWS, 1995; Jennings, 1990). It cannot compete with emergent species such as cattails (Typho sp.) or aggressive species that form dense monocultures such as Canada thistle (Cirsium arvense) and reed canarygrass (Pholaris orundinaceo) (USFWS, 1995). Common associates in Colorado's Front Range populations include redtop, marsh milkweed (Asclepias incarnates), bluejoint reedgrass (Colamagrostis conadensis), horsetail (Equisetum sp.), lobelia (Lobelia siphilitica), blue-eyed grass (Sisyrinchium sp.), goldenrod (Solidago sp.), arrowgrass (Triglochin sp.), and blue vervane (Verbena hastata) (USFWS, 1995). The Ute ladies' tresses orchid prefers soils ranging from fine silt and sand to gravels and cobbles. Occasionally, populations occur on highly organic or peaty soils. Soils composed of heavy or tight clay are typically unsuitable for this species. In addition, the orchid is not found in extremely saline or alkaline soils (pH >8.0) (USFWS, 1995). The orchid frequently colonizes early-successional riparian habitats including point bars, sand bars, and low lying gravelly, sandy, or cobbly edges. These preferred habitat characteristics suggest that this species requires early to mid-seral riparian habitats created and maintained by streams active within their floodplains (USFWS, 1995). 2