Application of ecological site information to transformative changes on Great Basin sagebrush rangelands

TitleApplication of ecological site information to transformative changes on Great Basin sagebrush rangelands
Publication TypeJournal Article
Year of Publication2016
AuthorsWilliamson J, Pierson FB, Spaeth K., Brown J., Al-Hamdan OZ, Weltz M.A., Nearing MA, Herrick JE, Boll J, Robichaud PR, Goodrich DC, Heilman P, D. Guertin P, Narvaez MHernandez, Wei H, Polyakov V, Armendariz G., Nouwakpo S, Hardegree SP, Clark PE, Strand EK, Bates JD, Metz L, Nichols MH
ARIS Log Number334822

Ecological Site Description (ESD) concepts are broadly applicable and provide a necessary framework to inform and guide rangeland management decisions.  In this paper, we demonstrate how understanding and quantification of key vegetation, hydrology, and soil relationships in the ESD context can inform rangeland assessments and targeting of management practices in Great Basin sagebrush steppe.  For the example presented here, integration of vegetation and relative estimates of runoff and erosion into the STM or ESD context identifies the ecohydrologic ramifications of each state transition and allows for more informed understanding of short- and long-term site responses to various management alternatives.  We did not consider other factors important to a land management decision process, such as land use designations or goals, cost and practicality of treatment alternatives, resource availability, and broader area management objectives, however, such information is easily accommodated into an ESD-based decision-making strategy/framework.  Although we present a single site-specific application, the same approach can be applied at the landscape scale.  RHEM model scenarios and ecohydrologic interpretations could be developed for selected states across multiple ecological sites at the landscape-scale.  RHEM is also the hillslope hydrology and erosion engine for the KINEROS2/AGWA model which enables simultaneous RHEM simulations across all hillslopes in one or more watersheds.  Model results supplementing current ESD information could be used to target and optimize conservation efforts across multiple sites for maximum ecological and economic benefit.  For example, tree removal may be more effective at locations with vegetation early in the juniper encroachment gradient and that have highly erodible soils.  An integrated ESD-RHEM approach across multiple sites would equip a decision maker to predict potential site responses and most effectively implement resources across a landscape.  The general approach presented here is not limited to sagebrush rangelands or to hydrologic and erosion processes.  We demonstrate how enhancement of ESDs with key ecohydrologic information can aid predictions of ecosystem response and targeting of conservation practices for sloping sagebrush rangelands that are strongly regulated by ecohydrologic or ecogeomorphic feedbacks.  Similar approaches could be applied to other rangeland ecosystems with other self-regulating processes, disturbances, and factors (e.g., wind erosion and evaporation on bare soils in flat terrain). We acknowledge that application of our approach may be difficult for sites with limited local knowledge and available data.  Building and assessing ecological models and predicting plant community and ecohydrologic responses to disturbances and management are inherently more difficult in cases with limited information.  A primary point of this work is that ESD concepts are flexible and can be creatively augmented for improved assessment and management of rangelands.