|Cox, S -|
|Likins, J -|
Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 12, 2011
Publication Date: December 30, 2011
Citation: Booth, D.T., Cox, S.E., Likins, J.C. 2011. Sagebrush-steppe wetlands and meadows of the upper Sweetwater river: A historical analysis. Society for Range Management Meeting Abstracts No. 0189. Technical Abstract: Montane wetlands and meadows spread, store, and regulate water flow while providing other valued ecological services. In 2002, R. V. Corning postulated that a grazing change from herded sheep to season-long free-roaming cattle on the high desert south of the upper Sweetwater River, had diminished the region’s wetlands. Areal extent is an ecological indicator for wetlands. We used aerial images (0.3- to 1-m GSD) collected at approximately 20-year intervals from 1948, to test for decreased wetland area. We used a 2008 aerial survey (systematic, intermittent, nested 1-, 8-, and 18-mm GSD) along 150 km of streams to look for erosion features. The historical images provided no evidence of a wetland-area trend. The 2008 aerial survey had 14 scenes (2%) showing headcuts and gullied or scoured channels, but had many scenes showing bare ground in meadows and wetlands from herbivore trailing. We conclude there has not been a loss of wetland and meadow area that could be detected at the locations and scales of our historical aerial imagery, but that active headcutting and channel scouring detected in the 2008 imagery is a serious threat to the affected drainages. The evidence of herbivore activity leads us to suggest the rate of soil organic matter replacement in meadows and wetlands should be evaluated. We show that 1-m GSD imagery is too low a resolution to detect channel erosion and we recommend riparian monitoring include systematic, intermittent sampling by acquisition of nested imagery on the order of 1, 8, and 18-mm GSD.