Plant Communities at James M Robb - Colorado River
Much of the landscape along the river was altered to support agricultural crops, urban landscaping and flood control projects. Plant species in these areas are indicative of reclaimed agriculture lands, such as crested wheatgrass, intermediate wheatgrass, smooth brome and wild rye. Soils are highly saline, thus the vegetation (both native and introduced) is generally salt tolerant.
The primary native plant communities at Colorado River are the following:• Desert shrubland • Saline bottomland shrubland • Skunkbush shrubland • Saltgrass grassland • Riparian shrubland, woodland, and herbaceous communities
Dry upland areas support desert shrubland communities dominated by sagebrush, shadscale, saltbush and greasewood. The best representations of big sagebrush communities are on the eastern end of the corridor, occupying high terraces along the river.
Saline bottomland shrubland featuring greasewood and four-wing saltbush occurs near 30 Road, while salt desert shrub communities dominated by shadscale occur throughout the entire corridor. A unique community of skunkbush shrubland, a remnant of the native vegetation, exists at Connected Lakes.
Skunkbush dominates the community with a smaller component of Wood’s rose, greasewood and rabbitbrush. Saltgrass grassland consisting of saltgrass, alkali sacaton, saltbush and rabbitbrush grows in a small area at Corn Lake.
Diverse wetland and riparian communities occur within and along the river corridor, on islands, point bars, ground water seeps, lake margins and constructed sites used for mitigation to offset development-related impacts. In these areas, herbaceous riparian communities of sedges, bulrushes, horsetail, cattails, reed canary grass, common reed and some sandbar willow have developed.
Greasewood dominates riparian shrublands occurring in alkaline depressions. In areas of riparian woodland, tree species are cottonwood, Russian olive, tamarisk, silverberry, green ash and Siberian elm; the latter five trees are exotic species.