Incorporating hydrologic data and ecohydrologic relationships in ecological site descriptions

Authors: Williams, Christopher - Jason; Pierson Jr, Frederick; SPAETH, KENNETH - Natural Resources Conservation Service (NRCS, USDA); BROWN, JOEL - Natural Resources Conservation Service (NRCS, USDA); AL-HAMDAN, OSAMA - University Of Idaho; Weltz, Mark; Nearing, Mark; Herrick, Jeffrey - Jeff; BOLL, JAN - University Of Idaho; ROBICHAUD, PETER - Us Forest Service (FS); Goodrich, David - Dave; Heilman, Philip - Phil; GUERTIN, PHILLIP - University Of Arizona; HERNANDEZ, MARIANO - University Of Arizona; WEI, HAIYAN - University Of Arizona; Hardegree, Stuart; STRAND, EVA - University Of Idaho; Bates, Jonathan - Jon; METZ, LORETTA - Natural Resources Conservation Service (NRCS, USDA); Nichols, Mary

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/22/2015
Publication Date: 1/1/2016
Citation: Williams, C.J., Pierson Jr, F.B., Spaeth, K.E., Brown, J.R., Al-Hamdan, O.Z., Weltz, M.A., Nearing, M.A., Herrick, J.E., Boll, J., Robichaud, P.R., Goodrich, D.C., Heilman, P., Guertin, P.D., Hernandez, M., Wei, H., Hardegree, S.P., Strand, E.K., Bates, J.D., Metz, L., Nichols, M.H. 2016. Incorporating hydrologic data and ecohydrologic relationships in ecological site descriptions. Rangeland Ecology and Management. 69:4-19.

Interpretive Summary: Ecological Sites (ES) and their descriptions (Ecological Sites Descriptions,ESDs) are the primary basis by which rangeland managers and management agencies evaluate ecosystem health, develop management objectives, target conservation practices, and communicate regarding ecosystem responses to management. However, ESDs seldom include ecohydrologic relationships that strongly regulate overall ecosystem health and responses to disturbances and management. This study developed a framework and methodology for integration of key ecohydrologic data and relationships within the ESD structure. The results include application of USDA developed rangeland hydrologic and erosion prediction technologies to the development and enhancement of ESDs. The integration of this new technology and framework on ecohydrologic relations expands the ecological foundation of the overall ESD concept for management of US rangelands. The proposed enhancement of ESDs will improve communication between private land owners and resource managers and researchers across multiple disciplines in the field of rangeland management.

Technical Abstract: The purpose of this paper is to recommend a framework and methodology for inclusion of key ecohydrologic feedbacks and relationships in Ecological Site Descriptions (ESDs) and thereby enhance the utility of ESDs for assessing rangelands and guiding resilience-based management strategies. Resilience-based strategies aim to assess and manage ecological state dynamics that affect state vulnerability, proximity to thresholds and transitions, and, therefore, provide opportunities for well-informed adaptive management. Many rangelands are spatially heterogeneous or sparsely vegetated where the vegetation structure strongly influences infiltration and soil retention. Infiltration and soil retention further influence soil water recharge, nutrient availability, and overall plant productivity. These key ecohydrologic relationships govern the ecologic resilience of the various states and community phases on many rangeland Ecological Sites (ES) and are strongly affected by management practices, land use, and disturbances. However, ecohydrologic data and relationships are often missing in ESDs and resilience-based state-and-transition models (STMs). To address this void, we used literature to determine the data required for inclusion of key ecohydrologic feedbacks into ESDs, developed a framework and methodology for integration of the required data within the current ESD structure, and applied the framework to a select ES for demonstrative purposes. We also evaluated the utility of the Rangeland Hydrology and Erosion Model (RHEM) for assessment and enhancement of ESDs based in part on hydrologic function. We present the framework as a broadly applicable methodology for integrating fundamental ecohydrologic relationships and feedbacks into ESDs and resilience-based management strategies. Our proposed framework increases the utility of ESDs to assess rangelands, target conservation and restoration practices, and predict ecosystem responses to management. The integration of RHEM technology and our suggested framework on ecohydrologic relations expands the ecological foundation of the overall ESD concept for rangeland management and is well aligned with the modern paradigm of resilience-based, adaptive management of US rangelands. We anticipate the proposed enhancement of ESDs will improve communication between private land owners and resource managers and researchers across multiple disciplines in the field of rangeland management.