resource conservation land use legacies
DESCRIPTION
69th SWCS International Annual Conference July 27-30, 2014 Lombard, ILTRANSCRIPT
Resource Conservation, Land Use Legacies, & Management Perspectives in Great Plains Agroecosystems
Benjamin L. Turner, Ph.D.With Dr. Roger Gates
July 2014
“Each soil has had its own history. Like a river, a mountain, a forest, or any natural thing, its present condition is due to the influences of many things and events of the past.”
– Charles Kellogg, The Soils That Support Us, 1956
Land use legacy: The impact that previous land use activities (i.e., legacy) have on ecosystem structure and function after those activities have ceased, potentially from years to centuries.
Conceptual basis: Adds explanatory power to understanding current conditions for ecological science (e.g., biogeochemical cycles; resilience) and conservation planning (e.g., biodiversity).
This presentation is about identifying land use legacies in Great Plains grassland‐cropland ecosystems.
Stakeholder engagement
Ecosystem assessment
Land use legacy impacts/consequences
Managing resources for a sustainable future
100th Meridian – Sustainable or Not?
Grassland conversion in the Great Plains
1. Data Collection: Stakeholders and Soils
Understanding land use legacies requires reconnecting ecosystem functions with previous human intentions.
Historical Data Collection
• Management interviews:– One 1‐hour interview (management philosophy).
• Operation & family history.• Goals, values, and land ethics. • Personal value of ecosystem goods and services. • Perspectives about grassland‐2‐farmland conversion.
– One site identification interview (hypothesis i.d.).• What sites have diverse land use history and why?
– 10 questions per site (experiments and learning).• Management tactics and observed performance.
…indigenous knowledge of those with greatest connection to local
system..
…knowledge to aid in others’ understanding.
Stakeholder Engagement100th Meridian
Four diversified ag operations:• Nationally recognized seedstock operation.• Environmental stewardship and grazing award winner.• Neighboring family operations with an array of farm‐
management strategies.
Conservation mindedValued diversity
Land ethic = integrity of ecosystemManagement by “mimicry”
Field Data Collection
• A soil “interview”:– Results of management experiments.– Interagency method.– 17 Indicators of Rangeland Health.
• Soil stability. • Hydrologic function.• Biotic integrity.
– Soil Organic Matter.
• Rangelands…and Farmlands?– Soil function vs. Farm decision support.
Available at: blm.gov/nstc/library/1734-6rev05.pdf
Soil Site Stability Hydrologic Function Biotic Integrity
Identifying Indicators of Ecosystem Health
The capacity of an area to limit redistribution and loss of soil resources (includingnutrients and organic matter) by wind and water.
The capacity of an area to capture, store, and safely release water from rainfall,run‐on, and snowmelt (where relevant), to resist a reduction in this capacity, andto recover this capacity when a reduction does occur.
The capacity of the biotic community (plants, animals, microorganisms, above and below ground) to support ecological processes within thenormal range of variability expected for the site, to resist a loss in the capacity tosupport these processes, and to recover this capacity when losses do occur.
Pellant, M., P. Shaver, D.A. Pyke, and J.E. Herrick. 2005. Interpreting indicators of rangeland health, version 4. Technical Reference 1734‐6. U.S. Department of the Interior, Bureau of Land Management, National Science and Technology Center, Denver, CO. BLM/WO/ST‐00/001+1734/REV05. 122 pp.
* Capacity – Resiliency – Recovery *
Ecosystem Indicator Soil Site Stability
Hydrologic Function
Biotic Integrity
1. Rills X X2. Water flow patterns X X3. Pedastals/Terracettes X X4. Bare ground % X X5. Gullies X X6. Wind‐scour, blowout or deposition areas X7. Litter movement X8. Soil surface resistance to erosion X X X9. Soil surface loss or degradation X X X
10. Plant community distribution relative to infiltration
X
11. Compaction layer X X X12. Functional/structural groups X13. Plant mortality/decadence X14. Litter amount X X15. Annual production X16. Invasive plants X17. Reproductive capability of perennials X
The three indicators that cover all three func ons → Soil
Highly dependent on previous land use.
Soil recoveryAggregate formationWater infiltration
Reconstructed land‐use legacies reveal interesting dynamics of ecosystem functions over time.
Soil protectionNutrient cyclingBiodiversity
2. Land‐use legacies: From General Trends to “Ghosts of the Past”
Cumulative indicator ratings show non‐abrupt transition between farming and grassland ecosystem functions.
So what type of land has changed in use?
Trend (R2=0.6977)
No/conservation till Various rotation types
Most sites have changed at least once in my lifetime.
Low score = 3Max score = 15
Land Capability Class: Moderate‐ to high‐productivity land changed the most.
Do any “ghosts” continue to exert themselves?
Most sites were LCC < 4
“Ghosts of Farmland Past”
Increasing presence of farming/cultivation
Increasing departure from capacity, resiliency, and recoveryFarm legacy impacts
were felt up to 20 yr.
Full recovery ≈60 yr.
“Ghosts of Grassland Past”
Increasing presence of grassland history.
Decreasing departure → Increasing capacity, resiliency, and recovery.
Less clear trends than “Farm Ghosts”
Better farming = better grasses?‐ Grass “on the margin”
Grass legacy erased by farm implementation?
Grass‐water legacy aiding in smaller departure than BI (likely in combination with better tillage and crop diversity).
*SSS departure is same as grassland sites (≈20 yrs).
Stability lost the longer cultivation continued.
Positive soil legacies expressed.
• BI positive post‐20 yearswith “margins”.
• HF likely due to better farm practices.
Whether increasing or decreasing, stability reached ≈20 yr.
What about Grazed Farmland sites?
Grazed farmland necessitates grassland nearby, potentially linking needed grain production with biodiversity conservation.
GFL rated the same or better than farming on most similar ecological sites.
Departure of GFL came from one location.
…and enhances opportunities to meet global demands of the future.
New research on Triple Bottom Line returns of coupled livestock‐cropping systems should prove valuable.
Image that supports conclusion
Questions?
In summary, a little grass goes a long way for maintaining ecosystem functions and integrity…