Ozarks streams have been aggraded by substantial quantities of gravel beginning at or near the time of European settlement. Historical data illustrate multiple, significant changes in land use that may have contributed to stream disturbance. The earliest change was replacement of riparian forest with cultivated fields and pasture, followed by extensive harvesting of shortleaf pine and oak during 1870 to 1920. Selective cutting of timber, use of livestock for skidding logs, and avoidance of steep slopes minimized increases in runoff and sediment supply from logging of uplands. Expanded use of valley bottoms for agriculture and roads, and extreme regional floods from 1895 to 1915 probably initiated significant stream disturbance during this period. The period during 1920-60 included the institution of annual burning of uplands, increased open-range grazing, and increased use of marginal land for row crops. Models for land-use controls on runoff and erosion indicate that this period should have been the most effective in creating stream disturbance. Historical sources corroborate that upland erosion was severe on small areas used for row crops and moderate on large areas subjected to seasonal burning. The most severe effect on streams, however, probably occurred during this period as a result of destruction of riparian vegetation by open-range livestock. From 1960-93, cultivated fields and pasture decreased, while cattle populations increased. Whereas some riparian areas have reverted to bottomland forest, this stabilizing effect occurs on only a small portion of valley- bottom land. Recovery processes aided by riparian vegetation are limited by channel instability and frequent, large floods.
Additional Publication Details
USGS Numbered Series
Historical land-use changes and potential effects on stream disturbance in the Ozark Plateaus, Missouri
U.S. Geological Survey ;
USGS Earth Science Information Center, Open-File Reports Section [distributor],