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Development, Current Status and Lessons Learned

Development, Current Status and Lessons Learned. Unpacking Equilibrium -Non-equilibrium Debate: Lessons Learned and Future Perspective David D. Briske Ecosystem Science & Management Texas A&M University. Turkana Region NW Kenya. Foundation of Range Management.

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Development, Current Status and Lessons Learned

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  1. Development, Current Status and Lessons Learned Unpacking Equilibrium -Non-equilibrium Debate: Lessons Learned and Future Perspective David D. Briske Ecosystem Science & Management Texas A&M University

  2. Turkana Region NW Kenya

  3. Foundation of Range Management A.W. Sampson 1919. Plant succession in relation to range management. USDA Bul. 791 E.J. Dyksterhuis1949. Condition and management of range land based on quantitative ecology. JRM 2:104

  4. Origin of Alternative Paradigm? Ellis and Swift JRM1988

  5. Non-equilibrium Persistent Model Ellis & Swift 1988

  6. Implications of NEP Model Antithesis of traditional range science that rejected: • Density-dependent regulation of plant production by livestock. • Concepts of carrying capacity and stocking rate. • Ability of grazing animals to adversely impact rangeland resources. Behnke, Scoones & Kerven 1993

  7. Motivation for NEP Ellis & Swift 1988 Failed African pastoral development programs were based on U.S. rangeland science. Need for programs originated from colonial narrative that pastoralism was backward and inefficient. NEP an attempt to explain why both the colonial narrative and U.S. range science were ineffective. Was pastoralism more effective than ranching?

  8. Motivation for NEP “the near universal failure of pastoral development suggests that something more fundamental is amiss” than technical incompetence of project managers or the intransigence of pastoralists - Ellis & Swift 1988.

  9. NEP Challenged Equilibrium asymptotically derived from extrapolation to larger scales (DeAngelis and Waterhouse 1987) . Minimize duality between biotic and abiotic drivers of rangeland dynamics (Sullivan 1996). Nonequilibrium models embraced with such enthusiasm that they were in danger of being misapplied just like equilibrium models Fernández-Giménez and Allen–Diaz (1999).

  10. Functional Heterogeneity Illius and O’Connor 1999

  11. Reinterpretation NEP Model Model overlooked heterogeneity of forage resource use. • Herbivores are coupled to a subset of ‘key’ resources accessible in dormant season i.e., biotic feedback. • Herbivores uncoupled from abundant growing season forage resources. • NEP emphasizes unique herbivore feedbacks with E and NE forage resources within landscapes. • Key resource areas determine herbivore persistence within landscapes. Illius & O’Connor 2000 Hempson et al. 2015

  12. Lessons Learned Equilibrial and nonequilibrial dynamics among plants and herbivores coexist within systems. Herbivore persistence is strongly influenced by functional resource heterogeneity. Biotic feedbacks are highly dependent upon spatial and temporal scale. Management and policy decisions are important in spite of high environmental stochasticity.

  13. Continued Misconceptions Multiple means of nonequilibrium • E&S – loosely coupled plant-herbivore interactions • Holling – system with weak basin of attraction • ‘Generic’ – systems possessing stochastic behavior that makes management difficult • Consistent with dynamic equilibrium • Ecological resilience describes this concept Are rangelands ever exclusively non-equilibrial?

  14. History of Rangeland Science Nathan F. Sayre Political Ecologist Geography Department Berkeley University Chicago Press 2017

  15. NEP Previously Recognized in U.S. Weather rather than livestock appeared to be a major driver of vegetation dynamics in SW – Griffiths1910. Woody plant encroachment replaced grasslands even with the best grazing management. USFS viewed this as a threat to scientific range management, but not to successional theory. Succession was more a policy than ecological theory. Sayre refers to these misinterpretations as ‘blind spots’ in rangeland profession.

  16. NEP - Blind Spot Made Visible Inescapable when U.S. range science was applied in semiarid, subsistence pastoral systems. Subsistence vs production Limited cash economy Indigenous knowledge Landscape mobility Institutional support

  17. Do Other Blind Spots Exist? Professional mindset inconsistent with reality regarding rangeland function and value. • Legacy or expediency • Unrecognized tradeoffs • New conditions/constraints • Alternatives unrecognized • Known unknowns • Unknown unknowns

  18. BS #1: Livestock Supplementation • Ellis & Swift – non-equilibrial conditions occur when herbivores are loosely coupled to rangeland forage. • Supplementation promotes non-equilibrium conditions by reducing livestock coupling to rangeland forage. • Replaces key resource areas and likely minimizes functional heterogeneity • Enhances potential for rangeland degradation by artificially maintaining livestock persistence • Multiple examples exist to support this interpretation

  19. BS #2: Provisioning Services Overemphasized Legacy of Pinchot and progressive era Limited production per unit area Land values exceed agricultural potential Other services taking on greater value

  20. BS #3: Continued Historic Climate Variability Change # Consecutive Dry Days Warming Drying Extreme events Magnified 2050 Appropriate response? NCA 2018

  21. Climate Signal on Beef Cattle #s

  22. BS #4: Ecological Knowledge Sufficient Anthropocene Epoch Does a unified model of rangeland ecology exist? Sufficient for 21st century rangeland stewardship? Management – science Policy –science Shifting societal values External drivers Globalized markets

  23. Rangeland Systems Framework Global rangelands function as complex, adaptive social-ecological systems. • Capacity to integrate social and ecological components. • Recognize and assess trade-offs among provisioning and non-provisioning ecosystem services. • How might this be best achieved? • What may provide a sufficient catalyst for action? • What organizations should be involved?

  24. Future Perspectives Michel de Nostradamus Rangeland Change Rapid change 20th century Accelerating change in 21st century Role of rangelands for humanity? Long-term view seldom explored Les Propheties 1555

  25. Scenario Planning Storylines of plausible future outcomes • Identification of major concerns or threats • Assessment of critical drivers and uncertainties • Development of potential scenario outcomes • Analysis of implications and potential interventions

  26. Rangeland Scenarios 2100 Provisioning Services Modern Pastoralism Grass Fed Beef Future Climate Variability Historic Climate Variability Energy Extraction New Wild West Cultural Services

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