Vegetation Classification and Mapping Project Report, Fossil Butte National Monument

Friesen, Beverly; Blauer, Steve; Landgraf, Kieth; Von Loh, Jim; Coles, Janet; Schulz, Keith; Tendick, Amy; Wight, Aneth; Wakefield, Gery; Evenden, Angela

The Northern Colorado Plateau Inventory and Monitoring Network worked with the support of the U.S. Geological Survey - National Park Service Vegetation Mapping Program to describe and map vegetation at Fossil Butte National Monument (FOBU). This collaborative effort involved many project partners, particularly the FOBU superintendent and natural resources staff, the Rocky Mountain Mapping Center of the U.S. Geological Survey, the Western Region office of NatureServe, engineering-environmental Management, Inc., and their cooperators.The mapping area is 6,217 ha (15,362 acres), encompassing the entire monument and an environs of adjacent public and private lands. Ecologists and photointerpreters cooperated to identify plant associations for FOBU and determine how best to map them using 1:12,000-scale, true color aerial photography and digital orthophotography. The team collected vegetation and environmental data from 158 vegetation classification plots and 97 observation points. Supplemental fuels data were collected in quaking aspen, Rocky Mountain juniper, limber pine, narrowleaf cottonwood, and Douglas-fir communities. Assessment of map accuracy entailed sampling 661 additional data points. Fieldwork and mapping were completed between 2005 and 2008.A managed burn of approximately 95 acres occurred in sagebrush communities on the western side of the monument after the aerial photography was flown and before the accuracy assessment data was gathered. Analysis of the plot data revealed 71 National Vegetation Classification plant associations, alliances, or park special vegetation types within the monument and environs. Four associations were documented from accuracy assessment data, the remainder from vegetation plots and observation points.Vegetation and land use were interpreted to as detailed a level as possible from high-resolution, 9” x 9” stereo pairs of 1:12,000-scale true color aerial photography and 1m resolution true color orthoimagery. Polygons representing common vegetation or land use map classes were delineated using computer-assisted segmentation and classification techniques, supplemented by manual digitizing of rare types. The project used the program standard minimum mapping unit of 0.5 ha (1.24 ac) with few exceptions.The FOBU vegetation mapping project area was divided into 1,709 polygons. A total of 1,687 map polygons represent 37 natural and semi-natural vegetation map classes. Two land use map classes describe 22 other polygons within the mapping area. Average polygon size across all map classes is 2.0 ha (5.0 acres). Natural and semi-natural vegetation classes cover 6,153 ha (15,205 acres; 98.7% of the project area). Land use polygons, including roads and NPS facilities, total 63.5 ha (156.9 acres; 1.3% of the project area). The most frequent vegetation mapping unit is the Low Sagebrush Shrubland (S-LOWS) with 646 polygons covering 2,161 ha (5,341 acres) or 35% of the project area. Results from a thematic accuracy assessment of 15 vegetation map classes remaining after accuracy assessment analysis indicated an estimate of 89% overall map accuracy (Kappa statistic = 85.7%).

Vegetation Classification and Mapping Project Report, Fossil Butte National Monument

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