Transitions in Rangeland Evaluations

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Jornada Experimental Range
Forest and Rangeland Ecosystem Science Center
Transitions in Rangeland Evaluations
David A. Pyke Jeffrey E. Herrick
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Rangeland Evaluations

• Age of Discovery - 1800s to 1930
• Rangeland Uses Abuses
• Observations
• Age of Inventory - 1930s to 1970s
• Described Vegetation, Production, Soils
• Taylor Grazing Act - Adjustments of AUMs
• Age of Planning Management - 1970s to 1990s
• Condition Trend
• Broader Objectives
• Age of Sustainability - 2000 to ????

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1905
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Age of DiscoveryWhat is the West? How can we use
it?
Powell

• Settlers expected consistent moisture
• Powell warned of the harsh environment
• Livestock successful use
• Livestock overuse observed by federal officials

Pinchot
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Succession Indicators

• Clements Sampson
• Plant communities change with grazing
• Grazing sensitive or preferred species are
  reduced
• Grazing tolerant and non-preferred increase
• Basis of Clements 1920 book on indicators

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Grazing Indicators

• Observations from -
• Smith, Bentley, Griffiths, Sampson, Jardine,
  Wooton Sarvis
• Certain species within communities are indicators
  of grazing abuse.

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1959
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Age of Inventory

• Dust Bowl leads to Taylor Grazing Act
• Required inventories of the amount of forage
  available for livestock
• Stoddart introduces rangeland condition classes
• Dyksterhuis relates Clementsian succession to
  condition classes
• Rangeland Classification
• Dyksterhuis
• Proposes range site concept
• Daubenmire
• Habitat types

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Monitoring Techniques Begin

• BLM
• Deming 2-phase
• Combination qualitative and quantitative
  (plot)data
• USFS
• Parker 3-step
• 100 points on transect with loop frequency/cover

K. W. Parker
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Monitoring Focus

• Vegetation tends to dominate over soils
• SCS still maintains soil-vegetation emphasis
• Forage plants undesirable plants are indicators
  of rangeland status
• Upland communities are the focus
• Lands around water sources tend to be sacrificed
• Wildlife habitat needs are secondary to livestock
  needs

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1978
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Heady 1975 Rangeland Mgmt.
Stoddart, Smith Box. 1975. Range Management
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Congressional Directions

• Forest Rangeland Renewable Resources Planning
  Act of 1974
• USFS Habitat types were mapped
• Federal Land Policy Management Act of 1976
• BLM Soil Vegetation Inventory Method (SVIM)
• Soil Water Resources Conservation Act of 1977
• National Resources Inventory (NRI)

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Inventory ? Condition Trend

• All agencies used some form of Dyksterhuis
  Condition Ratings
• Monitored trend using various techniques
• Biomass or cover
• Theory behind cond. trend was still Clementsian
  succession

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Utilization becomes Important

• Measure of the percent production consumed
• Direct via biomass
• Indirect via heightweight
• Done on a species-basis
• Difficult to determine utilization of pastures
• Estimated by ocular estimate maps

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Key Species

• Utilization by species lead to key species being
  monitored.
• Selected up to four species
• Utilization consistent over season
• Sufficient abundance and palatability for
  livestock
• Should make up the majority of forage

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Weakness of Key Species Concept

• Less abundant, highly palatable species are
  sacrificed
• Rangelands recovering from excessive livestock
  grazing in the early 1900s
• Former dominant, but palatable species would be
  rare
• Some dominant or co-dominant palatable species
  might have been sacrificed.
• Possible example - Basin Wildrye

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Introduction of New Ecological Concepts

• Biological Diversity
• Species richness, evenness
• Diversity among communities
• Non-equilibrium ecosystem dynamics
• State transition successional models
• Thresholds of community change
• Riparian and wetland communities as integral
  parts of rangelands
• Ecosystem processes
• Nutrient water cycles, energy flow

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Influential Documents in Changing Rangeland
Evaluations
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2004
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Age of Sustainability???

• West 2003 - Risk Assessment, Sustainability,
  Desertification
• Evaluations not focused on single use
• Evaluations strive to incorporate multiple scales
• Upland Riparian ecosystems often given equal
  weight in evaluations

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Upland Evaluations Community Dynamics
Reference State
Shrub - Annual Grass State
Threshold
Annual Grass State
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Evaluations of Ecosystem Processes

• Interpreting Indicators of Rangeland Health
• 3 Attributes (Site Stability, Hydrologic
  Function, Biotic Integrity 17 indicators with
  some overlapping
• Qualitative with Quantitative methods proposed
  being tested
• Landscape Ecosystem Analysis (Tongway et al)
• 3 indices (Stability, Infiltration, Nutrient
  cycling) Multiple indicators)
• Quantitative methods published

Soil/Site Stability
Hydrologic Function
Biotic Integrity
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Riparian, Wetland Aquatic
Bear Cr. 1977 Season long use

• Water quality measures
• Stream Geomorphic Classifications
• Stream Cross sections
• Veg. Classification based on soil and water table
  depth.
• Greenline techniques
• Proper functioning condition
• Wetland stream invertebrates

Bear Cr. 1987 Winter use
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National/Regional Assessments

• Sustainable Rangeland Roundtable
• 5 criteria measured indicators/criteria
• Ecological, Social Economic
• Heinz Center
• 10 national 14 grassland shrubland indicators
• Many indicators not populated
• NRI
• Rangeland NRI begun in 2003
• Non-federal lands

Sustainable Rangelands Roundtable
National Resources Inventory
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Remote Sensing GIS

• Combine soil, climate and current vegetation
• Large areas
• Allows for use of predictive models
• Invasion risk
• Erosion potential
• Useful for wildlife habitat assessments
• Multiple scales

Wisdom et al. 2003
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LandscapesPatterns, Processes, Resistance
Resilience

• Linkages across multiple scales
• Fragmentation monitoring
• Prediction ? early ID of threats and drivers
• Interactions among multiple threats

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Future Evaluations Carbon?

• Carbon Credits on Rangelands
• What could be included
• How to measure?
• International politics may dictate the need

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