PERMFILE110087 - Laserfiche WebLink

Home Browse Search

West EZk Mine of the highway embankment and the compaction that should have occurred during its construction, probably restrict groundwater flow to the river. The only drainage exit from the wetland area is a road culvert that has been blocked by animal activity; therefore, the only avenues of exit are evapotranspiration and seepage. Vegetation of the wetland community is chazacteristic of swamps or mazshes with relatively stagnant hydrologic conditions, and is dominated by old and senescent Populus angustifolia (narrowleaf cottonwood) individuals along the edges of the wetland, numerous Salix sp. (willow) clumps along the edges extending to the center, and a dense mixture of Typha latifolia (cattail), Carex sp. (sedges), and Agrostis alba (redtop). Approximately the west third of the wetland had standing water present in September 1995, while the remainder of the azea was subirrigated (no standing water on the surface, but saturated conditions below the ground surface). Total vegetation cover of this community was estimated between 50 and 65 percent. Herbaceous production was approximated to be between 200 and 300 g/m1 (1780-2675 lbs/acre). Woody plant density was estimated at 1000 stems/acre, dominated by the willow thickets. The small size and relative inaccessibility of this azea and vegetation community significantly limit its potential uses. Size of this community, as well as unpredictable subirrigation and/or surface flow effectively limits its usefulness as pasture or hayfield. While the community serves as wildlife habitat for residents of the RPE azea, the adjacent North Fork of the Gunnison provides a more diverse and high quality wildlife habitat. • A small side slope area (<0.01 acre) on the main slope of the RPE area was identified during the vegetation sampling as differing in visually dominant tree species (Figure 2). This area represents a seep from a bedrock outcrop or saturated surficial soil on the slope of the RPE azea. With a generally reliable moisture source, this small azea supports plant species with high moisture requirements. At this area, mature Populus angustifolia (nanowleaf cottonwood) individuals aze present along with Agrostis alba (redtop) and Salix sp. (willow). Vegetative characteristics and parameter values aze similaz to those of the relict oxbow wetland described above. Due to its small size, this minor community serves mainly as a source of cover and water for wildlife species utilizing the immediate RPE azea. A small inclusion (<2 acres) of the Douglas fir-Utah juniper vegetation community is present on the easternmost flank of the RPE area. Within the RPE azea this community is an association of mature Pseudotsuga menziesii (Douglas fir) and Juniperus osteosperma. The topography of the azea is chazacterized by rocky terrain and moderate slopes. The vegetation community is open and pazk- like between the mature trees. It is hypothesized that this azea, having shallower soils and more surficial sandstone fragments has allowed the shade intolerant Douglas fu to become established. As the azea has a more easterly aspect, the moisture regime may be slightly more xeric, explaining the presence of Juniperus osteosperma. In any event, this vegetation community is not chazacteristic ofthe RPE azea. 1.04-155 Revised November 2004 PRIO