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ECOLOGICAL SITES EXPANDING the CONCEPTS and APPLICATIONS of ECOLOGICAL SITES Joel Brown USDA NRCS

ECOLOGICAL SITES EXPANDING the CONCEPTS and APPLICATIONS of ECOLOGICAL SITES Joel Brown USDA NRCS Jornada Experimental Range Las Cruces NM. IMPORTANT POINTS Changing Conceptual Basis of Ecological Sites Applications - How can Ecological Sites be used for land management decision-making?.

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ECOLOGICAL SITES EXPANDING the CONCEPTS and APPLICATIONS of ECOLOGICAL SITES Joel Brown USDA NRCS

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  1. ECOLOGICAL SITES EXPANDING the CONCEPTS and APPLICATIONS of ECOLOGICAL SITES Joel Brown USDA NRCS Jornada Experimental Range Las Cruces NM

  2. IMPORTANT POINTS Changing Conceptual Basis of Ecological Sites Applications - How can Ecological Sites be used for land management decision-making? “Arcadia

  3. Ecological Site: A distinctive kind of land with specific physical characteristics that differs from other kinds of land in its ability to produce a distinctive kind and amount of vegetation, and in its ability to respond to management actions and natural disturbances. The purpose of an Ecological Site system is to divide landscapes into basic units for study, evaluation, and management Ecological Site Description (ESD): Reports with associated data that document the characteristics of an ecological site (including its climate, soils, and state-and-transition model) and the interpretation of its properties related to use and management.

  4. Ecological Site History: The site concept has undergone major revisions since its original development: Time: A shift from linear, predictable dynamics to an approach based on nonequilibrium dynamics (probabilities) Space: climate, geology, and edaphic properties are grouped together based on how they respond to change

  5. Important Concepts In Dividing the Landscape Spatial scale – what is a site? Temporal scale- how does change occur?

  6. Regionswith similar climate, land use Geographicareaswith similar soils Similar landscapepatterns Groups of EcologicalSitesthat share landscapes Intermingledecologicalsitesor single site Individual representativeof thesite Anobservation of plant-soilrelationships

  7. LAND RESOURCE REGIONS • LRR J-SOUTHWESTERN PRAIRIES • 84A – Cross Timbers (Kansas, Oklahoma, and T exas) • 84B – West Cross Timbers (Oklahoma and Texas) • 84C – East Cross Timbers (Texas) • 85 – Grand Prairie (Oklahoma and Texas) • 86 – Texas Blackland Prairie (Texas) • 87 – Texas Claypan Area (Texas) MLRAs

  8. MLRAsdistinguishbroaddifferences in potential and types of ecologicaldynamics Non-native grass invasion, increased fire frequency, loss of native woody plants Non-native grass invasion, altered surface hydrology, reduced productivity Drought-triggered forest dieback Nonnative woody plant invasion Perennial grass loss, soil erosion, native woody plant dominance Native woody plant thickening, reduced fire frequency MajorLandResourceAreas USDA NRCS

  9. The LRU (local climate, soils and geology) refines and supports MLRA concepts Gravelly soil (shallow, relict piedmont) Surface soil water limited, high risk for grass loss and erosion: vulnerable/restorable Limestone Grass protected by rocks, higher rainfall, good water capture: low risk Sandy soil (relict basin floor) Erodible surface soils once grasses removed: vulnerable/hard to restore Soil mapping units of the Jornada Basin (15 km) Loamy soil (active piedmont) Susceptible to water erosion and grass loss: vulnerable/restorable Clayey soil (basin floor) Receives water and sediment: low risk From Bestelmeyer et al 2010

  10. Within LRUs are clusters of sites with similar parent material, but differing in landscape position Each site has a typical soil profile

  11. A soil map unit can contain more than one ecological site because map units may contain components Map unit/components Ecological site ST: Stellar association 40% Stellar clay loam, 0-3% slopes = Clayey 40% Stellar clay loam, 0-3% slopes, flooded = Bottomland 20% other inclusions BK: Berino-Dona Ana association 50% Berino fine sandy loam, 1-5 % slopes = Sandy 30% Dona Ana fine sandy loam, 1-5% slopes = Sandy 20% other inclusions OP: Onite-Pajarito association 40% Onite loamy sand, 1-4% slopes = Sandy 30% Pajarito fine sandy loam, 0-5% slopes = Sandy 15% Pintura fine sand, 0-5% slopes = Deep sandy 15% other inclusions An ecological site groups several similar soil map unit components

  12. EcologicalSite Concept An Ecological Site is based on a core concept with a defined amount of variability (in the climatic, geologic and edaphic properties). Variability in the temporal dynamics of the vegetation is not considered. An Ecological Site Description describes the distinguishing geophysical properties of a site in one section and its temporal dynamics in another section.

  13. Describing Temporal ChangeSoil/Vegetation Concepts • Existing vegetation can not be a primary ecological site criterion because it is easily manipulated therefore highly variable. • The ecological site concept should be developed, using geophysical attributes that enable identification of the ecological site without vegetation on the site.

  14. Applications of EcologicalSites and EcologicalSiteDescriptions The utility of Ecological Sites is based on the ability to systematically stratify the landscape according to varying ecological potential

  15. Uses of EcologicalSites and EcologicalSiteDescriptions Assess the risk of persistent degradation (undesirable change) and take proactive measures to avoid it Transition (T) Slow variables and triggers Chronic heavy defoliation coupled to multi-year drought events Threshold Black grama grass cover loss to < 3% and inability to recover continuity via vegetative growth

  16. Uses of EcologicalSites and EcologicalSiteDescriptions Specify constraints to desired ecosystem change, estimate their probability of occurrence and devise contingencies

  17. Uses of EcologicalSites and EcologicalSiteDescriptions Design and interpret monitoring based on expected responses to management or climatic changes.

  18. Information can be aggregated (Inventory) SpatioTemporal pattern detection (Prediction and Intervention) Predicted responses to climatic, socioeconomic factors (Modeling) Impacts of policy and program decisions (Assessment) Ecological Site Information Applications at Larger (LRU, MLRA and LRR) Scales

  19. Narratives for states and communities contain indicator values and management strategies to promote resilience. Knowledge of the amounts and spatial distribution of these requirements can inform policies and programs Reference state Black grama-creosotebush savanna (historical + extant) Indicators/Diagnosis Bouteloua eriopoda >15% foliar cover, Larrea tridentata <12% foliar cover, little erosion Ecological Feedbacks Perennial grass continuity promotes soil and water retention and fire Management Summer grazing rest in drought, fire every 20 years Reference community phase Bouteloua eriopoda (15-60% foliar cover), Larrea tridentata (1-5% foliar cover) At-risk community phase Bouteloua eriopoda (3-5% foliar cover), large bare patches Alternative states Shrub-dominated, shrubland states 1.1A 1.1 Reference community 1.2 Another Community 1.2A 1.3A 1.2B 1.3 At-risk community 1.Savanna state T1A R1A 2.1 Community 2.1A 2.2A 3.1 Community 2.2 Community 2. Shrub-dominated state 3. Shrubland state T2A

  20. Threeawn Mesquite Black grama Tobosa Threeawn Black grama Threeawn (Yucca) Burrograss Tobosa Tobosa Black grama Tobosa Dropseeds Tobosa Burrograss Tobosa Tarbush Burrograss Threeawn Mesquite/Yucca Threeawn To date the application of Ecological Site concepts has been limited to rangeland ecosystem dynamics Loamy SD-2 Tobosa/ Black grama Mesquite 2a 2b Burrograss Tarbush/Creosotebush Black grama-tobosa grassland 3a 1a 1b Shrub-invaded grassland 3b 4 Tarbush or mesquite Tobosa/burrograss 5 Mesquite/creosotebush Tobosa/burrograss Burrograss-tobosa-threeawn grassland Shrub-dominated As Ecological State changes, the values and ecosystem services associated with the site change

  21. Land Use and Land Management Changes Can Alter Ecosystem Services Regardless of Land Use ECOSYSTEM SERVICES ECOLOGICAL SITE PROVISIONING food, fibre CLIMATE SUPPORTING water cycling, nutrient cycling, primary production GEOMORPHOLOGY ECOLOGICAL STATE HISTORICAL AND CURRENT MANAGEMENT PRIOR ECOSYSTEM SERVICES FUTURE ECOSYSTEM SERVICES LANDSCAPE POSITION CULTURAL educational, recreation, heritage SOIL PROPERTIES REGULATING climate, waste control, pollination From Brown and MacLeod 2011

  22. Land cover/use classifications are increasingly useless in making policy decisions people change land use frequently ecological processes are much more complex and variable than a land use category resistance and resilience are vital to predicting ecosystem behavior landscape scale models require ecological process information to allow sites to interact

  23. The status of ecologicalsites • In May 2010 agreementby NRCS, ForestService, and Bureau of Land Management toadoptecologicalsites as a commonframework • Interagencyecologicalsiteworkinggroupisbeingformed • November 2010 InteragencyWorkshop-PilotprojectsfordevelopingecologicalsitesfollowinginteragencyrequirementsbeingconsideredforcertainMLRAs (regions). • August 2011 InteragencyFieldWorkshop Cheyenne WY • November 2011 InteragencyFieldWorkshop Venus FL • 2012-Reno NV, Cheyenne WY • New SoilEcologydivisionwithin NRCS NationalSoilSurvey Center and new staff in regional offices: 53 new full-time positions dedicatedtoESDs, includingcropland

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