Assessing runoff and erosion on woodland‐encroached sagebrush steppe using the Rangeland Hydrology and Erosion Model

Ecosphere

Kenneth E. Spaeth¹  Osama Z. Al‐Hamdan²  Patrick R. Kormos³  Scott E. Shaff⁴  S. Kossi Nouwakpo⁵  Frederick B. Pierson⁶  C. Jason Williams⁷  Justin C. Johnson⁷  Viktor O. Polyakov⁷ 

[1] Central National Technology Support Center, Natural Resources Conservation Service US Department of Agriculture Fort Worth Texas USA;Civil and Architectural Engineering Texas A&M University‐Kingsville Kingsville Texas USA;Colorado Basin River Forecast Center, National Oceanic and Atmospheric Administration—National Weather Service US Department of Commerce Salt Lake City Utah USA;Forest and Rangeland Ecosystem Science Center US Geological Survey, US Department of the Interior Corvallis Oregon USA;Northwest Irrigation and Soils Research, Agricultural Research Service US Department of Agriculture Kimberly Idaho USA;Northwest Watershed Research Center, Agricultural Research Service US Department of Agriculture Boise Idaho USA;Southwest Watershed Research Center, Agricultural Research Service US Department of Agriculture Tucson Arizona USA;

关键词: cutting;    fire;    Great Basin;    hydrologic recovery;    infiltration;    islands of fertility;   

DOI  :  10.1002/ecs2.4145

来源: DOAJ

【 摘 要 】

Abstract The transition of sagebrush‐dominated (Artemisia spp.) shrublands to pinyon (Pinus spp.) and juniper (Juniperus spp.) woodlands markedly alters resource‐conserving vegetation structure typical of these landscapes. Land managers and scientists in the western United States need knowledge and predictive tools for assessment and effective targeting of tree‐removal treatments to conserve or restore sagebrush vegetation and associated hydrologic function. This study developed modeling approaches to quantify the hydrologic vulnerability and erosion potential of sagebrush rangelands in the later stages of woodland encroachment and in response to commonly applied tree‐removal treatments. Using experimental data from multiple sites in the Great Basin Region, USA, and process‐based knowledge from decade‐long vegetation and rainfall simulation studies at those sites, we (1) assessed the capability of the Rangeland Hydrology and Erosion Model (RHEM) to accurately predict patch‐scale (12 m2) measured runoff and erosion from tree canopy and intercanopy hydrologic functional units in untreated and burned woodlands 9 years postfire, and (2) developed and evaluated multiple RHEM approaches/frameworks to model aggregated effects of tree canopy and intercanopy areas on patch‐ and hillslope‐scale (50 m length) runoff and erosion processes in untreated and treated (burned, cut, and masticated) woodlands. The RHEM accurately predicted measured runoff and sediment yield from patch‐scale rainfall simulations as partitioned on untreated and treated tree canopy and intercanopy areas and effectively parameterized the dominant controls on runoff and erosion process in woodlands. With few exceptions, evaluated hillslope‐scale RHEM frameworks similarly predicted reduced hydrologic vulnerability and erosion potential for conditions 9 years following tree removal by burning, cutting, and mastication treatments. Regressions of RHEM‐predicted hillslope runoff, sediment, and hydraulic/erosion parameters with bare ground and ground cover attributes indicate all RHEM frameworks effectively represented the dominant controls on hydrologic and erosion processes for rangelands and woodlands. The results provide RHEM frameworks and recommendations for assessing hydrologic vulnerability and erosion potential on woodland‐encroached sites and predicting the effectiveness of tree removal to reestablish a water and soil resource‐conserving vegetation structure on sagebrush rangelands. We anticipate our RHEM or similar modeling approaches may be applicable to analogous water‐limited landscapes elsewhere subject to woody plant encroachment.

【 授权许可】

Unknown