Educational Module 1

Weather Variability (Time and Space)

Learning Objectives

  • Understand the nature of weather variability at a single location
  • Understand spatial weather variability across the Great Basin
  • Learn to use the Restoration Climatology Report for historical assessment and site characterization.
  • Discuss how weather variability might affect or inform: single-year ESR planning; interpretation of field treatment effects; restoration EA development and adaptive management planning.


Millions of hectares of rangeland in the western United States have already undergone type conversion to invasive annual and woody species (Johnson and Miller, 2008; Germino et al., 2016).  Restoration of these rangelands is confounded by a generally arid or semi-arid climatology, and extremely high seasonal and annual variability in weather (Hardegree et al., 2012a).  The high probability of unfavorable weather conditions in any given year contributes to low rates of restoration success regardless of the choice of planting and seedbed preparation treatment, adequacy of weed control measures, or suitability of plant materials (Hardegree et al., 2011).

Microclimatic conditions necessary for the initial establishment of desirable range plants occur infrequently (Call and Roundy, 1991; Peters, 2000; Westoby et al., 1989).  It is, therefore, unreasonable to expect full success of restoration efforts in any given year.  Single-year seeding events in the year following wildfire, however, are the primary management treatment in response to annual grass invasion and dominance (Eiswerth and Shonkwiler, 2006; Eiswerth et al., 2009; Kulpa et al., 2012).  Development of effective future strategies to restore western rangelands will require a more fundamental understanding of the impact of weather and site variability on the successional processes driving plant community change.  The purpose of this exercise is to provide the tools for interpreting weather impacts on historical seeding success, and to start you thinking about how knowledge of weather variability might affect your strategy for long-term rangeland restoration planning and adaptive management.  The desired outcome is to provide a weather-centric orientation for future managers that have to deal with this variability in the context of Emergency Stabilization and Rehabilitation (ESR; USDI-BLM, 2007) planning, long-term restoration planning under the requirements of the National Environmental Policy Act (NEPA; USDI-BLM, 2008), and state and federal expectations for implementation of Adaptive Management guidelines (Williams et al., 2009).

Suggested Reading/Viewing Assignments

  • Hardegree, S.P., J. Cho and J.M. Schneider.  2012a. Weather variability, ecological processes, and optimization of soil micro-environment for rangeland restoration.  In: T.A. Monaco and R.L. Sheley (Eds.).  Invasive Plant Ecology and Management: Linking Processes to Practice.  CAB International, Wallingford, Oxon. pp. 107-121. PDF
  • Hardegree, S.P., J.M. Schneider and C.A. Moffet.  2012b. Weather variability and adaptive management for rangeland restoration.  Rangelands 34:53-56. PDF
  • Hardegree, S.P., J.M. Schneider, C.A. Moffet and A.R. Boehm.  2012c. Using weather data to improve decision making for rangeland restoration efforts.  USDA-ARS.  Ecologically Based Invasive Plant Management Program Guidebook.  18 pp. PDF
  • USDI BLM (U.S. Department of Interior, Bureau of Land Management), 2008.  National Environmental Policy Act handbook.  BLM Handbook H-1790-1, USDI BLM, Washington, DC. 174 p. PDF
  • USDI BLM (U.S. Department of Interior, Bureau of Land Management), 2007.  Burned area emergency stabilization and rehabilitation handbook (public).  BLM Handbook H-1742-1, USDI BLM, Washington, DC. 80 p. PDF
  • Williams, B.K., Szaro, R.C., Shapiro, C.D., 2009.  Adaptive management: The U.S. Department of the Interior technical guide.  Adaptive Management Working Group, U.S. Department of the Interior, Washington, DC. 72 pp. PDF
  • Webinar on weather variability and forecasting tools for short and long-term restoration planning:


  • Historical daily weather information from the 4-km Gridmet database for the period January 1, 1979 through the current year (Abatzoglou, 2013).
  • Restoration Climatology Report

Laboratory Exercise

Step 1 - Pick a location or a string of locations across the Great Basin and download historical site data

Using the Weather Variability form (below), enter latitude and longitude information and download historical daily weather data and a Restoration Climatology Report for your site(s).  You can pick one of your previous seeding project locations,the location of an historical BLM seeding project extracted from the Land Treatment Digital Library (, a location for which you are developing a land management or rangeland restoration plan, or a string of locations along a latitudinal or longitudinal gradient.

Fill out the Weather Variability form.

Step 2 - Spreadsheet analysis

Open your weather data file(s) in a spreadsheet application and manipulate the data to identify patterns of seasonal and annual variability in precipitation and temperature, and for any other variable of interest.  Identify at least three elements or patterns that you believe would have a significant impact on the relative success of rangeland restoration at your site or across multiple sites.

Step 3 - Evaluate the Restoration Climatology Report

Look through the Restoration Climatology Report(s) for your site(s) and pick 5 random years for analysis.  Evaluate each year in terms of annual, seasonal and monthly precipitation and the distribution of potential mortality hazards (freezing and short-term soil drought) and develop your own rationale for ranking years and/or locations for potential restoration success.  If you have data from historical plantings, include those years in your analysis and see whether your assessment of weather impacts matches what was experienced in the field.

Step 5 - Synthesis

Synthesize strategies to overcome barriers to establishment based on your analysis of individual years and/or sites, and the information provided in the Report for your location.  Select from one of the synthesis/discussion questions below, or generate your own discussion topics.  This synthesis is not a simple discussion of the results of your hypothesis testing but should be broader in scope and address how your results inform broader management questions related to restoration planning, policy issues, or adaptive management.

  • How do you think you could use this information for adaptive management planning?
  • What are the ramifications for short-term and quick-response ESR planning?
  • How might you incorporate your knowledge of site variability into the NEPA planning process?
  • How might you hedge your bets to improve restoration success?
  • How might this information be relevant to seedbed manipulation and planting treatments?