Author
NOELLE, SARAH - University Of Arizona | |
CRAIG, A - Montana State University | |
STRINGHAM, TAMZEN - University Of Nevada | |
Weltz, Mark |
Submitted to: Review Article
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/13/2017 Publication Date: 6/21/2017 Citation: Noelle, S.M., Craig, A.A., Stringham, T.K., Weltz, M.A. 2017. Slash application reduces soil erosion in steep-sloped piñon-juniper woodlands. Review Article. 70(6):774-780. Interpretive Summary: The Great Basin is the largest North American desert covering more than 122.5 million acres. One of the biggest threats to ecosystem stability and integrity in the Great Basin is expansion of native woody plants. The alteration of native plants communities by these invasive species has increased the likelihood of damaging and dangerous wildfires and soil erosion. Mitigating runoff and associated erosion is a fundamental challenge for sustainable management of rangelands. Hillslope runoff and erosion are strongly influenced by ground cover, thus, a strategic management option exists to increase cover with slash from removal of piñon and juniper trees. The majority of studies assessing slash effects on runoff and erosion have been limited to shallow slopes however, substantial portions of rangelands exist on steeper slopes where the effectiveness of slash application has not been clearly documented. On a steep > 30% black sagebrush ecological site that had been encroached by piñon and juniper trees we evaluated the effectiveness of slash in reducing runoff and erosion using a portable rainfall simulator (100-year return period events). Total runoff did not differ with either plant cover or slash levels however sediment yield was different for the treatments evaluated. Sediment yield for plots with low vegetation cover was 3.5 times greater than those with high cover, while plots with slash present experienced 5 times less sediment yield than plots without slash. These results extend findings from shallow to steep slopes, highlighting the potential benefit of slash application to intercanopy patches for reducing soil erosion in steeply sloped rangelands. Technical Abstract: Mitigating runoff and associated erosion is a fundamental challenge for sustainable management of rangelands. Hillslope runoff and erosion are strongly influenced by ground cover, thus, a strategic management option exists to increase cover with slash from woody plant removal activities particularly on lands experiencing woody plant invasion or infilling. The majority of studies assessing slash effects on runoff and erosion have been limited to shallow slopes however, substantial portions of rangelands exist on steeper slopes where the effectiveness of slash application is less clear. On a steep (30% ± 5%) black sagebrush ecological site that had been encroached by piñon and juniper trees we evaluated the effectiveness of slash in reducing runoff and erosion using a portable rainfall simulator (100-year return period events). Total runoff did not differ with either plant cover or slash levels however sediment yield did. Sediment yield for plots with low vegetation cover was 3.5 times greater than those with high cover, while plots with slash present experienced 5 times less sediment yield than plots without slash. These results extend findings from shallow to steep slopes, highlighting the potential efficacy of slash application to intercanopy patches for reducing erosion, in steep-sloped rangelands. |