National Park Service U.S. Department of the Interior Natural Resource Program Center Vegetation Classification and Mapping Project Report, Hovenweep National Monument Natural Resource Technical Report NPS/NCPN/NRTR—2008/092 USGS-NPS Vegetation Mapping Program Hovenweep National Monument ON THE COVER Cutthroat Castle ruin, Hovenweep National Monument (Photograph courtesy of the National Park Service) ii USGS-NPS Vegetation Mapping Program Hovenweep National Monument Vegetation Classification and Mapping Project Report, Hovenweep National Monument Natural Resource Report NPS/NCPN/NRTR—2008/092 Jim Von Loh engineering-environmental Management, Inc. Englewood, Colorado Gery Wakefield and Aneth Wight Southeast Utah Group / Northern Colorado Plateau Network National Park Service Moab, UT Angie Evenden Northern Colorado Plateau Network National Park Service Moab, Utah Janet Coles Northern Colorado Plateau Network National Park Service Moab, Utah April, 2008 U.S. Department of the Interior National Park Service Natural Resource Program Center Fort Collins, Colorado iii USGS-NPS Vegetation Mapping Program Hovenweep National Monument The Natural Resource Publication series addresses natural resource topics that are of interest and applicability to a broad readership in the National Park Service and to others in the management of natural resources, including the scientific community, the public, and the NPS conservation and environmental constituencies. 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National Park Service, Fort Collins, Colorado. NPS D-40, April 2008 iv USGS-NPS Vegetation Mapping Program Hovenweep National Monument Contents SUMMARY ................................................................................................................................. xi ACKNOWLEDGEMENTS ..................................................................................................... xiii INTRODUCTION.........................................................................................................................1 Vegetation Classification and Mapping Project, Hovenweep National Monument............................................1 The USGS-NPS Vegetation Mapping Program...................................................................................................1 Northern Colorado Plateau Network Inventory and Monitoring Program ........................................................1 Vegetation Mapping Program Standards ...........................................................................................................2 National Vegetation Classification Standard......................................................................................................2 Other Standards ..................................................................................................................................................4 PROJECT AREA DESCRIPTION.............................................................................................5 Location and Setting ...........................................................................................................................................5 Topography.........................................................................................................................................................7 Climate................................................................................................................................................................8 Geology and Vegetation......................................................................................................................................8 Vegetation Change............................................................................................................................................12 Soils...................................................................................................................................................................13 Biological Soil Crusts .......................................................................................................................................13 Hydrology and Water Resources.......................................................................................................................14 Land Use ...........................................................................................................................................................14 Previous Vegetation Studies..............................................................................................................................15 PROJECT OVERVIEW ............................................................................................................16 General Approach and Timeline.......................................................................................................................16 Primary Partners and Project Roles.................................................................................................................17 Aerial Photography...........................................................................................................................................18 Scoping Meeting................................................................................................................................................18 Project Boundary and Map Extent....................................................................................................................18 Minimum Mapping Unit....................................................................................................................................20 Ecological System Classification ......................................................................................................................20 VEGETATION CLASSIFICATION AND DESCRIPTION .................................................21 Pre-Field Methods ............................................................................................................................................21 Preliminary Classification List ................................................................................................................21 Legacy Data Review................................................................................................................................21 Field Methods ...................................................................................................................................................21 Field Sampling Approach........................................................................................................................21 v USGS-NPS Vegetation Mapping Program Hovenweep National Monument Plot Data Collection ................................................................................................................................22 Data Processing and Analysis..................................................................................................................25 Observation Points...................................................................................................................................25 Classification Data Analysis.............................................................................................................................26 Shadscale / Herbaceous Group ................................................................................................................28 Sagebrush Group .....................................................................................................................................29 Dwarf-shrub or Herbaceous Group .........................................................................................................30