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Soil and Ecosystem Dynamics in Soil Survey. Susan Andrews, Ph.D. Ecology NRSC NSSC National Leader Soil Quality and Ecosystems June 17, 2013. NRCS. Three Main Areas of Responsibility:. Soil Quality (SQ) Dynamic Soil Properties (DSPs) Ecological Sites (ESs). 103. 103. 103. 250. 103.
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Soil and Ecosystem Dynamics in Soil Survey Susan Andrews, Ph.D. Ecology NRSC NSSC National Leader Soil Quality and Ecosystems June 17, 2013 NRCS
Three Main Areas of Responsibility: • Soil Quality (SQ) • Dynamic Soil Properties (DSPs) • Ecological Sites (ESs) 103 103 103 250 103
1. Soil Quality in Soil Survey • NRCS Soil Health Initiative • SQEB has technical development responsibility • Emphasis on decision support and assessment tools
Soil Quality Definitions “capacity of the soil to function” - Karlen et al. 1997 “fitness for use” - Larson & Pierce, 1991
Kinds of Soil Quality • INHERENT SOIL QUALITY • DYNAMIC SOIL QUALITY • reflects natural characteristics • based on soil forming factors • climate, parent material, topography, and biota, all acting over time – Jenny, 1941 • describes status or condition of soil • result of land use or management practice • after Pierce and Larson, 1993
Dynamic SQ Dynamic SQ with respect to Inherent capability 50% 85% Relative Assessment Inherent SQ Soil Function Soil A Soil B - After Andrews et al., 2004
Soil Health v. Soil Quality • Soil health is used as a synonym for soil quality - Doran and Parkin, 1996 • Minor exceptions: • Health often includes only dynamic quality • Health some greater emphasis on biology A soil may have poor inherent soil quality but still have good soil health. • Gregorichand Carter, 1997
Soil Health RAT • Tool to assess soil health, by: • Selecting simple indicators • Interpreting results • Based on function • WRT inherent soil properties • Providing basic management advice • Part of the CDSI Mobile Planner • Will beta-test MS Access version
Soil Quality Priorities • Develop tools and interpretations • Revision of test kits and guides • Identify and interpret effects of soil function • Simple tools for conservation planning (RAT) • Advise the Soil Health Management Initiative • Inform trainers & others of the latest science • Inform farm bill policy
2. Dynamic Soil Properties in SS An inventory of soil changeover the human time scale, due to: - human management- natural disturbance Millennia -Richter and Markowitz, 2001 • Decades and less - the management time scale • Decades to centuries - the recovery time scale -Tugel et al., 2005 Centuries Decades
Improve Accuracy of SS Databases (and provide reference values for SQ indicators) Soil organic matter • Important for C-sequestration, water holding capacity, agg. stability, pesticide applications, nutrient applications (Grossman, unpublished)
103 103 103 250 103 Develop Interpretations of Management Effects on Soil Function • The importance of soil change is its affect on function. • The consequences of change depend on its reversibility. (Arnold et al.,1990) Land degradation Productivity Land use impacts
Soil with low resistance and high resilience Soil with low resistance and low resilience Differences in Resistance and Resilience Soil with high resistance Soil Function Time (years) Compaction Disturbance -Seybold et al., 1999
Main DSP Priorities • Identify best ways to inform conservation • Develop new methodologies to rapidly populate the database • Models and pedotransfer functions • Validation sampling design • Hire postdoc for data mining and modeling • Sampling, assessment & analyses training • Standards and database requirements
3. Ecological Sites in Soil Survey • Partnership with S&T Ecological Sciences Division and National Grazinglands Team • New standards follow basic MLRA planning • Soil Survey offers procedures for control and assurance and the correlation process • To succeed, we (NCSS) must work in interdisciplinary teams
Ecological Site Definition • An ecological site is a distinctive kind of land based on: • recurring soil, landform, geological, and climatic characteristics that differs from other kinds of land • in its ability to produce distinctive kinds and amounts of vegetation, and • in its ability to respond similarly to management actions and natural disturbances.
State-and-Transition Definitions STATE - a recognizable, resistant and resilient complex of two ecosystem components: the soil base and the vegetation structure - Soils help determine the site’s capabilities - The interaction between soil and vegetation determines the functional status of the site and it’s inherent resistance to change. “Steady” States Vegetation attribute(s) Time Stringham, et al., 2003
State-and-Transition Definitions TRANSITION - the trajectory of a change - change is precipitated by natural events, management actions, or both - degrades the integrity of one or more of the state’s primary ecological processes beyond the point of self-repair THRESHOLD – boundary in space and time between two states -irreversible for practical purposes thresholds Vegetation attribute(s) transitions Time
State-and-Transition Model Post oak/blackjack oak/little bluestem ESD, Missouri Hot summer burn and /or long-term grazing Burn, Site prep & Planting / Seeding. No grazing or limited controlled grazing Post oak/buckbrush (or similar) Lacks mid-story. Understory single species woody dominated Canopy: open 30-90% Post oak/flowering dogwood/ tick trefoil-goldenrod. Multi-story. Canopy: 30-90% Harvest, site prep, seeding Abandonment for 20+ yr with recruitment of woody natives Westoby, et. al., 1989 Stringham et.al., 2001 Pasture (improved) Non-native grass sod
Working Definition of a Agroecological Site • An agroecologicalsiteis a subset of an Ecological Site (ES) based on: • recurring soil, landform, geological, and climatic characteristics that differs from other kinds of land (within one ES) • in its potential to support distinctive ranges of soil functions (as indicated by dynamic soil properties), and • in its ability to respond similarly to management actions and natural disturbances.
Land Management Optimization (LMO) Model High Attainable for Forage Crops Production Group Ecological Potential Attainable for Grain Rotations Production Group ForageCrops Grain Rotation Root Crops Soil Functions / Ecosystem Services Native / NaturalizedPlantCommunities Resource Concern / Function Threshold Vegetable Rotation Degradation / Resilience Threshold Low Agricultural Production Groups within an Agroecological Site Native/ Naturalized States
Land Management Optimization for one Production Group EcologicalPotential Grain Rotations Attainable for Grain Rotations Production Group Continuous no-till w/ cover crops Organic system w/ cover crops Soil Functions / Ecosystem Services Resource Concern Threshold Diverse rotation, tillage Rotation, low-till, no cover crops Monocrop, Deep tillage Degradation / Resilience Threshold Disturbance within one Agricultural Production Group
Main ES Projects and Priorities • ES Policy and Standards (final revisions) • Database Requirements (review stage) • ES for Additional Land Uses • Crop (pilot stage) & pasture (planning stage) • Riparian (review stage) • Wetlands, Subaqueous (new, some work) • Development of Hierarchical Classification • Training, Communications and Outreach
Comments and Questions? Contact: susan.andrews@lin.usda.gov