Riparian stubble height and recovery of degraded streambanks
-
-
Authors: W. P. Clary, C. I. Thornton, and S. R. Abt
Date: 1996
Journal: Rangelands
Volume: 18
Number: 4
Pages: 137-140
Summary of Methods: A laboratory study was conducted to evaluate the potential of stiff (sedge and corn) and flexible stemmed (bluegrass, native sod) vegetation to trap and retain sediment on a meandering stream with characteristics common in the Intermountain region at the Hydraulics Laboratory at Colorado State University. Three treatments (no vegetation, rigid vegetation, flexible vegetation) were applied, with four stubble heights (rigid - 3.0, 8.0, 10.0, and 14.0, flexible -0.5, 3.0, 8.0, and 14.0). These live vegetation mats were inserted into the stream channel and the ability of plants to capture and retain sediment (fine sand) were tested at discharge rates of 3.0, 5.0, and 6.8 cfs. Sediment capture and retention rates were primarily tested under a single water cycle event.
Article Summary / Main Points: The presence of vegetation resulted in trapping up to 700% more sediment than the no vegetation treatment. Taller rigid vegetation reduced sediment deposition due to deflecting the water, whereas flexible vegetation created a turbulent zone resulting to increase sediment deposition. Stubble heights from 0.5 to 6 inches resulted in maximum sediment deposition and retention for both rigid and flexible vegetation in a single cycle simulation. Rigid vegetation retained less sediment than flexible vegetation.
Vegetation Types:
MLRA Ecoregions: Not Applicable
Agrovoc Control Words: Riparian zones Grazing Streams
Article Review Type: Peer Reviewed
Article Type: Experimental Research
Keywords: stubble height, degraded streambanks, riparian habitats, sediment deposition, simulated meandering stream channel, sediment retention, flexible stems, stiff stems
Annotation: A very limited number of multiple (up to 4) cycle scenarios were conducted in the study testing only flexible stemmed vegetation. After four cycles, short stubble heights (0.5 to 3 inches) and long stubble heights(8 to 12) retained a similar amount of sediments as the short stubble was unable to capture and retain additional sediment, while long stubble heights continued to capture and retain additional sediments. This limited number of multiple cycle treatments showed that, potentially, stubble height recommendations should take into account the cyclic nature of streams during a given growing seasons as areas that are subject to multiple or prolonged flushing events should receive different grazing recommendations. Due to the limited number of multiple cycle tests that the authors conducted, additional research examining the abilities of varied heights of vegetation to capture sediment from water would be beneficial. Final recommendations include a stubble height (12 inches) that was not tested in the experiment.
-
Direct link not available.
-