Submitted to: Management of Landscapes Disturbed by Channel Incision Stabilization Rehabi
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/1997
Publication Date: N/A
Interpretive Summary: Riparian areas bordering streams in agricultural areas may be impacted by both channel incision (increase in channel depth due to erosion) and gully erosion. Restoration of these areas can be expensive and time consuming and require careful planning. A common low cost construction measure used in a demonstration project in the Yazoo Basin of Mississippi to halt gully erosion which originates from overbank flow is a field-scale grade control structure or drop pipe. This structure creates small natural habitat which is quickly colonized by local vertebrates. We evaluated the effectiveness of the structure in habitat creation by sampling fish and wildlife utilizing terrestrial areas and undergoing gully erosion and these created habitat types. The results indicate that installation design of these structures can be altered to facilitate habitat creation more effectively. Installation designs which result in increases in pool depth and total habitat area will provide the greatest benefits for vertebrates living in these riparian areas. These changes can be utilized by both state and federal resource managers attempting to restor riparian areas impacted both channel incision and gully erosion.
Technical Abstract: Field-scale grade control structures, or drop pipes, are the most common grade control structures installed as part of the Demonstration Erosion Control project in the Yazoo Basin. A by-product of installing such an erosion control structure is the replacement of eroding gullies with riparian habitats located adjacent to deeply incised streams. Four created habitat types may result and are classified as follows: upland meadow, saturated emergent wetland, scrub-shrub wetland, and intermittent riverine wetland. We assessed vertebrate communities at three terrestrial sites undergoing gully erosion and four of each created habitat type with a variety of sampling techniques. We identified a total of 100 species from 4,276 captures in all habitat types. Upland meadows had the lowest mean species richness of all habitat types. Mean species richness of saturated emergent wetlands was not significantly greater than gully erosion sites, while mean species richness of scrub-shrub wetlands and intermittent riverine wetlands was significantly higher. Therefore, habitat creation from drop pipe installation is an unintentionally added value. Our results suggest that standard installation practices of drop pipes can be altered to facilitate habitat creation more effectively. These improved installation practices will be proficient tools for restoration of riparian zones impacted by both channel incision and gully erosion.