Laserfiche WebLink
ATTACHMENT D <br /> Canada thistle (Cirsium arvense)are also present. Large, mature plains cottonwood (Populus <br /> deltoideis) trees border the sides of the wetland (Photo 7). Table 2 lists the vascular plant <br /> species identified on the Amen Gravel Pit project site during field reconnaissance in May 2018. <br /> 6.1.2 Ecological Condition and Land Use History <br /> Wetland A is located north of the Big Thompson River in an area that did not show evidence <br /> of recent grazing. Flood-deposited sediments were not observed in this area. <br /> 6.1.3 Results <br /> Wetland A is located in a swale that is cut off from the active river system. This wetland does <br /> not contain the early-seral riparian habitat that is often associated with the Ute ladies' tresses <br /> orchid and Colorado butterfly plant. The NRCS soil survey indicates the area is mapped as <br /> Bankard Sandy Loam, 0-3% slopes, frequently flooded (Figure 4). This soil type is compatible <br /> with the Ute ladies' tresses orchid and Colorado butterfly plant, as it would allow for <br /> subirrigation. However, given the plant communities that were observed during field <br /> reconnaissance, Wetland A is unlikely to support the We ladies tresses orchid or Colorado <br /> butterfly plant. Specifically, the common associates were not present and instead the moist <br /> soil habitat at the periphery contains aggressive species such as quackgrass, Canada thistle, <br /> and broadleaf pepperweed. These aggressive plants typically out-compete the Ute ladies' <br /> tresses orchid and Colorado butterfly plant, and therefore Wetland A is unlikely to support <br /> these two rare plants. <br /> 6.2 Wetland B <br /> 6.2.1 Location, Hydrology and Vegetation <br /> Wetland B is a small seasonal aquatic site measuring 437 square feet (0.01 acre) (Photo 8).The <br /> depression is seasonally saturated to inundated by the shallow groundwater table and has a <br /> sparse cover of threesquare bulrush at the perimeter. The overstory is a mature cottonwood <br /> gallery forest. <br /> 6.2.2 Ecological Condition and Land Use History <br /> Wetland B is not a part of the active river system and it is surrounded by aggressive, <br /> introduced grasses. There is no early seral habitat. <br /> 6.2.3 Results <br /> Wetland B has soil that is suitable for both the Ute ladies' tresses orchid and Colorado butterfly <br /> plant, with a gravelly substrate that interacts with the seasonally high groundwater table. <br /> However, the presence of introduced, aggressive grasses at the margin and the lack of early <br /> seral habitat and common associates indicate this area is not suitable habitat for these two <br /> rare plants. <br /> 6.3 Wetlands C & D <br /> 6.3.1 Location, Hydrology and Vegetation <br /> Wetlands C and D are located in swales on the south side of the Big Thompson River. Wetland <br /> C measures approximately 733 square feet (0.02 acre) (Photo 9) and Wetland D measures <br /> approximately 404 square feet (0.01 acre) (Photo 10). These depressions are historic <br /> secondary channels of the Big Thompson River which are seasonally saturated by the alluvial <br /> aquifer. Wetland C is dominated by saltmeadow rush growing with quackgrass. Wetland D <br /> has a sparse cover of threesquare bulrush growing with saltmeadow rush, saltgrass, and curly <br /> 4 <br />