1 / 29

Transitions in Rangeland Evaluations

Forest and Rangeland Ecosystem Science Center. Jornada Experimental Range. Transitions in Rangeland Evaluations. David A. Pyke & Jeffrey E. Herrick. Rangeland Evaluations:. Age of Discovery - 1800’s to 1930 Rangeland Uses & Abuses Observations Age of Inventory - 1930’s to 1970’s

Télécharger la présentation

Transitions in Rangeland Evaluations

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


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

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

  3. 1905

  4. 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

  5. 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

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

  7. 1959

  8. 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

  9. 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

  10. 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

  11. 1978

  12. Heady 1975 Rangeland Mgmt. Stoddart, Smith & Box. 1975. Range Management

  13. 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)

  14. 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

  15. Utilization becomes Important • Measure of the percent production consumed • Direct via biomass • Indirect via height:weight • Done on a species-basis • Difficult to determine utilization of pastures • Estimated by ocular estimate maps

  16. 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

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

  18. 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

  19. Influential Documents in Changing Rangeland Evaluations

  20. 2004

  21. 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

  22. Upland Evaluations & Community Dynamics Reference State Shrub - Annual Grass State Threshold Annual Grass State

  23. 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 Biotic Integrity Hydrologic Function

  24. 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

  25. National/Regional Assessments Sustainable Rangelands Roundtable • 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 National Resources Inventory

  26. 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

  27. Landscapes:Patterns, Processes, Resistance & Resilience • Linkages across multiple scales • Fragmentation monitoring • Prediction  early ID of threats and drivers • Interactions among multiple threats

  28. Future Evaluations: Carbon? • Carbon Credits on Rangelands • What could be included • How to measure? • International politics may dictate the need

More Related