Can Shade Structures Help Riparian Areas?
Rangelands , 27 , 2005
Davison, J. C., Neufeld, J. D.
The damage caused by unmanaged cattle grazing on riparian habitats is well documented.1 At the same time, ample evidence exists that well-managed cattle grazing is compatible with maintaining, and even improving, riparian habitats.2 The key to creating stream-friendly grazing systems is to reduce the amount of time cattle spend in these sensitive riparian habitats.3 We faced this challenge when we began our study on Antelope Creek during the spring of 1996. Antelope Creek is located on private land approximately 40 miles north and east of Battle Mountain, Nevada. The active stream channel had dropped to approximately 10–15 feet below the surrounding valley bottom, and bank erosion still occurs during high spring runoff events. Although many positive improvements had already been begun, we were interested in methods to foster continued improvements along this stream. Antelope Creek has already formed a small floodplain, and herbaceous, riparian plant communities are reestablishing along most of the banks. Intermittent willow clumps are also growing along the length of the stream. Established methods to exclude cattle from riparian areas along sensitive stream banks include fencing and the development of off-site water and mineral sources. Some researchers have even tried genetic selection of cattle herds and negative conditioning with electrical shock.4,5 In the spring of 1996, we began a project to determine whether constructed shade structures could reduce the amount of time cattle spend in the Antelope Creek riparian areas and, in turn, the impacts on riparian plant communities from grazing. The shades were intended to provide a more desirable location for cattle to loaf and ruminate than the adjacent riparian habitats that had little or no shade. Previous research that showed benefits in cattle production were primarily confined to feedlots and dairies,6,7 and studies that concerned themselves with shade in range and pastures systems had conflicting results.8–11 Our main goals were to determine whether 1) artificially constructed, shaded areas would be used preferentially by significant numbers of cattle in place of adjacent riparian bottoms; and 2) riparian-vegetation use classes, as estimated by stubble height and currentyear shrub use, were lower adjacent to the shade structures when compared with the nonshaded areas, and if so, how far out from the structures. Our project was conducted for 3 years, and changes in water quality (chemical analysis), riparian vegetation, and the size and shape of the stream bank were also investigated. We will not report these results here.We are focusing on the effects of constructed shade areas on Antelope Creek because of the recent interest and recommendations for use of shade to control cattle movements.