Hierarchy for Ecological Sites (LRR, MLRA, LRU, Soil-Landscape Properties) Interagency Ecological Site Applications Workshop Winnemucca, NV June 5-7, 2012

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<ul><li>Slide 1</li></ul> <p>Hierarchy for Ecological Sites (LRR, MLRA, LRU, Soil-Landscape Properties) Interagency Ecological Site Applications Workshop Winnemucca, NV June 5-7, 2012 Herman B. Garcia Ecological Site Inventory Specialist USDA-NRCS Phoenix AZ Slide 2 What are Land Resource Regions? Land Resource Regions (LRRs ) are a group of geographically associated major land resource areas. There are 28 LRRs described across the conterminous United States, Alaska, Pacific Basin Region, Hawaiian Region, and the Caribbean Region. United States Department of Agriculture Handbook 296 Land Resource Regions and Major Land Resource Areas of the United States, the Caribbean, and the Pacific Basin Slide 3 LRR - D Western Range and Irrigated Region D Slide 4 SE receive warm summer rains elsewhere in the region, however, most of the precipitation falls during the cool season. freeze-free period ranges from 105-260 days soils are dominantly Aridisols, Entisols, and Mollisols dominantly mesic soil temperature regime aridic soil moisture regime and mixed mineralogy This is a semidesert or desert region of plateaus, plains, basins, and many isolated mountain ranges. 549,725 square miles average annual precipitation 6 42 inches average annual temperature 40-60 degrees F Slide 5 Slide 6 What are Major Land Resource Areas (MLRAs)? Major land resource areas are geographically associated land resource units. 23 MLRAs are identified within LRR D Over 300 MLRAs are currently described Slide 7 Nevada MLRAs 24Humboldt Area Area is in Nevada and Oregon -12,680 square miles. -Winnemucca Nevada Physiographythe Great Basin Section of the Basin and Range Province of the Intermontane Plateaus Elevation 3,950-5,900 feet to 8,850 feet mountain peaks Geology wide valleys, N to S trending isolated ranges are uplifted fault-block mountains Climateaverage annual precipitation is 6-12 inches as much as 40 inchesSummers are dry. The average annual temperature is 38-53 degrees F freeze-free period averages 135 days and ranges from 100 to 175 days Soils dominant soil order is Aridisols Torriorthents (Boton series) in loess and alluvium over lacustrine sediments Biological Resources Shrub-grass veg Slide 8 Nevada MLRAs 25Owyhee High Plateau Area is in Nevada, Idaho, Oregon, and Utah -28,930 square miles -Elko, Nevada, Physiographywithin the Intermontane Plateaus... separated by narrow, aggraded Desert N. half within the Columbia Plateaus Province...NE corner has deep, narrow canyons draining into the Snake River. Elevation ranges 3,000 -7,550 feet 9,840 feet on some steep mtns. Geology dominant rock types in the area are volcanic - andesite, basalt, and rhyolite Cretaceous granitic rocks occur in the mountains. Only a few narrow valleys occur in this area. Climate AAP is 7-16 inches and exceed 50 InchesPpt evenly - fall, winter, and spring The average annual temperature is 35-53 degrees F freeze-free period avg 135 days Soils dominant order are Aridisols and mollisols Biological Resources Shrub-grass veg- high plateaus support juniper and mahogany Slide 9 What are Land Resource Units (LRUs)? Land resource units (LRUs) are the basic units from which major land resource areas (MLRAs) are determined. LRUs are generally several thousand acres in size Synonymous with Common Resource Areas (CRAs) in 2005 Ecological Sites are the building blocks for LRUs Slide 10 Slide 11 Regions with similar climate, land use Geographic areas with similar soils Similar landscape patterns Groups of Ecological Sites -share landscapes Intermingled ecological sites or single site One individual representative of the site An observation of plant-soil relationships Slide 12 Ecological Cross-References MLRAForest Service SectionEPA Level III Ecoregion% of MLRA 24 Humboldt Area341E Northern Mono13 Central Basin and Range67 24 Humboldt AreaM341D W Great Basin and Mtns 13 Central Basin and Range17 24 Humboldt Area342B Northwestern Basin and Range 80 Northern Basin and Range10 24 Humboldt Area341G Northeastern Great Basin 13Central Basin and Range6 25 Owyhee High Plateau 342C Owyhee Uplands80 Northern Basin and Range43 25 Owyhee High Plateau 341G Northeastern Great Basin 80 Northern Basin and Range13 25 Owyhee High Plateau 341G Northeastern Great Basin 13 Central Basin and Range13 25 Owyhee High Plateau 342J Eastern Basin and Range 80 Northern Basin and Range11 25 Owyhee High Plateau M341A East Great Basin and Mtns 13 Central Basin and Range7 Source: USDA Ag Handbook 296;Appendix I </p>

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