Ecosystem services of riparian areas: stream bank stability and avian habitat
Riparian areas are transitional zones between terrestrial and aquatic ecosystems. The riparian areas investigated in this thesis are transitions between row-cropped uplands and lower order streams. Riparian areas can serve many functions such as filtering pollutants from overland flow, stabilizing stream bank, storing surface water and sediment, and maintaining biodiversity by providing wildlife habitat. In response to concern about the loss of ecosystem services once provided by natural riparian systems, state and federal agencies have established incentive programs for landowners to convert sensitive lands from agricultural to conservation uses. Soil conservation and water quality are two important riparian functions that were investigated in the first study which measured stream bank erosion. This study was conducted in NE Missouri on stream reaches with different riparian land use/vegetation. The second study focused on the enhancement of wildlife habitat in riparian areas. It compared avian communities within a chronosequence of riparian buffers established on previously cropped or pastured land with those of the nearby matrix land cover types (row crop fields and an intensively grazed pasture). The results of the bird survey support the establishment of designed riparian buffers including trees, shrubs, and/or grass to increase habitat for many bird species in highly modified landscapes such as the agriculturally dominated Midwest. However, the results of the stream bank erosion study did not show that natural perennial vegetation (trees and shrubs) was reducing stream bank erosion in northeast Missouri. Riparian areas are complex and much more research is needed to understand how to utilize and improve their natural functions.