Geologic Influences on Ecological Sites Along Mountain Fronts A Case Study in Cochise County, AZ Elizabeth Desser, Geosciences Undergraduate – University of Arizona Mentor: Philip Heilman, USDA/ARS - Southwest Watershed Research Center Photo by Philip Heilman, USDA-ARS

Topics to cover  Project objectives  Project background  Research methods  Results & Interpretations  Conclusions

Project Objectives  Need: Reduce time of NRCS Range Conservationists to map ecological sites in the field.  Map ecological sites by relating soil map units and ecological sites to underlying geology and reduce mapping error.  Use results to assess feasibility for statewide mapping improvements.

Project background Soil The unconsolidated mineral or organic material on the immediate surface of the earth that serves as a natural medium for the growth of land plants. (NRCS) Soil Formation Equation: S = f (P,C,R,B,T) (Hans Jenny, 1941) S = soil P = parent material (geology) C = climate R = relief (topography) B = biota T = time classification/orders/images/ari disol.jpg

USDA Soil Survey for Cochise County - Douglas Tombstone Part (AZ671)

Ecological Site  can produce a specific vegetation community  distinct boundaries  created for management and planning, not research s/NC/SYMBOLS/images/honey bee.jpg kipedia/commons/thumb/5/5c /Velvet_mesquite.jpg/586px- Velvet_mesquite.jpg es/calendar/RedFlowers.jpg mmon/detail/99/41/ jpg s/pronghorn.jpg opped.jpg

Limy Upland Sandy Loam mm/yr Creosote - Tarbush 70 kg/ha/yr Limy Upland Sandy Loam mm/yr Creosote - Tarbush 70 kg/ha/yr Clay Upland Clay mm/yr Tobosa Grass 150 kg/ha/yr Clay Upland Clay mm/yr Tobosa Grass 150 kg/ha/yr Sample Ecological Sites Name: Soil: Precip: Vegetation: Production: Name: Soil: Precip: Vegetation: Production: Near Chihuahua, Mexico

Clay loam upland Elgin: 50% in/yr precipitation Clay loam upland Elgin: 50% in/yr precipitation Inclusions 10% Inclusions 10% Limy slopes Stronghold: 40% in/yr precipitation Limy slopes Stronghold: 40% in/yr precipitation MAPPING ERROR: 50% (due to secondary soil and inclusions) OVERALL MAPPING ERROR FOR AZ 671: ~ 33% MAPPING ERROR: 50% (due to secondary soil and inclusions) OVERALL MAPPING ERROR FOR AZ 671: ~ 33%

Sedimentary Rock Elgin-Stronghold Complex Granitoid Rock

Conclusions  There is a need to improve Arizona-wide mapping and grouping of ecological sites and relating SSURGO map units may help in this regard.  For certain areas, the underlying geology may be useful in sorting out soils in given GIS polygons.  Continued research into Cochise County may set an example for the rest of Arizona.

Acknowledgements  NASA Space Grant  Anthony Pitucco, Pima Community College  Philip Heilman, USDA-ARS, SWRC  Chandra Holifield Collins, USDA-ARS, SWRC  Jesse Wood, NRCS  Emilio Carrillo, NRCS  Phil Pearthree, AZ Geological Survey  Donald Pool, USGS  Jared Buono, USDA-ARS, SWRC  Tobias Finke, USDA-ARS, SWRC ppies_closeup.jpg

Make sure you’re on the correct side of the fence before closing the gate!

Questions? Photo by Philip Heilman, USDA-ARS

Thank you!