|Costigan, Katie -|
Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 5, 2009
Publication Date: February 7, 2010
Citation: Costigan, K., Weltz, M.A., Stone, J.J., Morris, C.E. 2010. Concentrated Flow Erosion after Pinyon-Juniper Cutting [abstract]. Society for Range Management and Weed Science Society of America Annual Meeting Program Guide. O-9. Technical Abstract: Post-European settlement has resulted in woody plant encroachment and infill across the Great Basin and present large-scale consequences for hydrologic process on rangelands. The focus of this paper is to describe the hydrologic impact of hand felling Pinyon and Juniper trees perpendicular to the slope to provide barriers to overland flow, reduce velocity of concentrated flow, and minimize soil erosion. Experimental design consisted of two cover conditions (naturally occurring bare interspaces and slash piles from felled trees on naturally occurring bare interspaces) at two slope steepness (30% and 10%) and three concentrated flow water application rates. Water was applied from a specially designed flow initiator at 15, 30 and 42 liters/minute for 12 minutes to quantify the treatments ability to reduce concentrated erosion rates. Three replicates for each treatment-slope-water application rate combinations were performed. The research indicates that hand felling Pinyon and Juniper trees can be highly successful in reducing the size of concentrated flow path, its velocity, and sediment load. However, if trees are not perpendicular to the slope they can actually concentrate flow and accelerate soil erosion. The overall success of this treatment for reducing concentrated flow erosion will depend on the spatial distribution of the slash piles (distance between slash piles) and the orientation of the slash piles. This research is being used by the USDA to develop concentrated flow equations for inclusion of the Rangeland Hillslope Erosion Model being developed in support of the USDA Conservation Effects Assessment Project.