Filters: partyWithName: Tom Owens (X) > partyWithName: Joseph H Wlosinski (X)
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An experiment to improve ecological conditions while maintaining a 9-foot (2.74-m) navigation channel was continued in 1995 and 1996 on the three pools of the Upper Mississippi River managed by the St. Louis District, U.S. Army Corps of Engineers. Water levels were held from 1 to 3 feet (0.3 to 0.9 m) lower than maximum regulated elevations at the dam from about mid-June through July in Pools 24 and 25 and Melvin Price Pool. Water levels were then gradually raised as discharge allowed. Vegetation was surveyed along an elevational gradient in eight areas in 1995 and six areas in 1996. Seven plant genera were identified in 1995 and five genera in 1996. Amaranthus spp. (pigweed), Cyperus spp. (chufa), Echinochloa spp....
Describing the status of the Upper Mississippi River is a continuing function of the Long Term Resource Monitoring Program. Some ecologically important characteristics that serve as indices of overall system status include depositional habitats, vegetation, invertebrates, fish biodiversity, and our capability to apply information to achieve ecological goals. Individual conditions, however, must be regarded as elements of a comprehensive ecological perspective. The filling of depositional aquatic habitats has been measured sufficiently to identify this as the major long term resource problem in navigation pools. However, extrapolating sedimentation rates from one location to another for the purpose of focusing rehabilitation...
The floodplain of the Upper Mississippi River has been significantly modified by man since 1824. Changes include the removal snags and sandbars, elimination of rapids, closing of side channels, construction of wing dams, 29 navigation locks and dams, and hundreds of miles of levees. Watershed changes have transformed much of the landscape from forest/grassland habitats to agriculture. We studied floodplain changes by analyzing historical water elevation and discharge data collected since 1861 and spatial data since 1891. Open water and marsh habitats have generally increased in the dammed portion of the river. A 28% reduction in open water and a 38% reduction in woody and terrestrial habitats have occurred In areas...
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