Long-term vegetation, hydrology, and erosion responses to tree removal by prescribed fire, cutting, and mastication in sagebrush steppe

Authors: Williams, Christopher - Jason; PIERSON JR, FREDERICK; NOUWAKPO, S.K. - UNIVERSITY OF NEVADA; AL-HAMDAN, O.Z. - TEXAS A&M UNIVERSITY; KORMOS, PATRICK; Weltz, Mark; VEGA, S - UNIVERSITY OF IDAHO

Submitted to: Society of Range Management
Publication Type: Abstract Only
Publication Acceptance Date: 10/30/2017
Publication Date: 1/28/2018
Citation: Williams, C.J., Pierson Jr, F.B., Nouwakpo, S., Al-Hamdan, O., Kormos, P.R., Weltz, M.A., Vega, S. 2018. Long-term vegetation, hydrology, and erosion responses to tree removal by prescribed fire, cutting, and mastication in sagebrush steppe. Abstract Proceedings of the 71st SRM Annual Meeting, Technical Training, and Trade Show, Empowerment through Applied Science, January 28-February 2, 2018, Nugget Hotel, Sparks, NV. p. 441.

Interpretive Summary: Land managers across the western US are faced with selecting and applying effective tree-removal treatments on sagebrush rangelands, but current understanding regarding long-term ecohydrologic responses to tree removal remains inadequate. This study used vegetation measures, rainfall simulations, and overland flow experiments to evaluate the impact of prescribed fire, tree cutting, and shredding tree-removal treatments on vegetation and hydrology and erosion processes at two sites 9 yr after tree removal. All treatments were effective at recruiting sagebrush steppe vegetation, but burning also increased cheatgrass cover in isolated patches around burned trees. High rates of runoff and erosion were reduced by tree removal treatments at one site, but were minimally altered at a second more degraded site. Collectively, the study demonstrates that prescribed fire and mechanical tree-removal treatments can effectively re-establish sagebrush steppe vegetation attributes and improve hydrologic function, but also show that hydrologic recovery can require more than 9 yr on more degraded sites as vegetation increases over time.

Technical Abstract: Land managers across the western US are faced with selecting and applying effective tree-removal treatments on sagebrush rangelands, but current understanding regarding long-term ecohydrologic responses to tree removal remains inadequate. This study used vegetation measures, rainfall simulations, and overland flow experiments to evaluate the impact of prescribed fire, tree cutting, and shredding tree-removal treatments on vegetation and hydrology and erosion processes at two sites 9 yr after tree removal. All treatments were effective at recruiting sagebrush steppe vegetation, but burning also increased cheatgrass cover in isolated patches around burned trees. High rates of runoff and erosion were reduced by tree removal treatments at one site, but were minimally altered at a second more degraded site. Collectively, the study demonstrates that prescribed fire and mechanical tree-removal treatments can effectively re-establish sagebrush steppe vegetation attributes and improve hydrologic function, but also show that hydrologic recovery can require more than 9 yr on more degraded sites as vegetation increases over time.