Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/19/2011
Publication Date: 1/29/2012
Citation: Hardegree, S.P., Cho, J. 2012. Weather data, site variability, and probabilities of success: a practical perspective on adaptive management. In: Abstracts of the 65th Annual Meeting, Society for Range Management, Spokane, WA, Jan 29-Feb 3, 2012 (CD-ROM Abstract).
Technical Abstract: Arid and semi-arid rangelands occupy over half of the earth’s surface and are characterized by high variability in seasonal and annual precipitation. Invasive plants compete for soil and water and exacerbate inherent weather limitations for desirable plant establishment. Management guidelines for rangeland restoration are driven by actions designed to optimize water availability to desirable plant species during critical establishment periods, but climatological information is generally used only to make initial decisions about general species suitability. More detailed seasonal weather information is often available, but is commonly only used retrospectively to explain seeding failure. Current state-and-transition models acknowledge that there are a limited set of potential trajectories for moving between undesirable and desirable vegetation states. Ecological Site Descriptions include general climate information such as annual precipitation ranges, average monthly temperature minima and maxima, seasonality, and growing-season characteristics, but do not address the probabilities associated with transition pathways that are influenced by weather variability. Adaptive management alternatives should be viewed in the context of weather ranking during the establishment season being evaluated. If the seasonal conditions were significantly below average, it may not be necessary to abandon strategies that did not seem to work in that particular year. Lessons learned from successful management actions should also be weighed in the context of relative weather favorability. Multi-year evaluation should be considered when comparing alternative management treatments, and multi-year treatments may be necessary to achieve acceptable levels of establishment success at a given site.