Vegetation Classification and Mapping Project Report, Capitol Reef National Park [and associated files]

Coles, Janet; Clark, Debi; Dela Cruz, Michelle; Clark, Tom; Topp, Sarah; Evenden, Angie; Wight, Aneth; Wakefield, Gery; Von Loh, Jim

With the support of the U.S. Geological Survey - National Park Service Vegetation Mapping Program, the Northern Colorado Plateau Network Inventory and Monitoring Program described and mapped existing vegetation at Capitol Reef National Park (CARE). This collaborative effort involved many project partners, particularly the Natural Resources staff of Capitol Reef National Park, the Western Region office of NatureServe, engineering-environmental Management, Inc., and their cooperators. The mapping area is 146,754 hectares (362,637 acres), encompassing the entire park as well as an environs of adjacent public and private lands. Ecologists and photointerpreters worked together to identify plant associations for CARE 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 243 vegetation classification plots and 17 observation points to supplement a vegetation data set of 305 plots sampled in 1986-1988. Assessment of map accuracy entailed sampling another 1313 plots. Fieldwork and mapping were completed between 2002 and 2005. Analysis of the classification plot data revealed 175 National Vegetation Classification plant associations, alliances, or park special vegetation types within the Park and environs. Thirteen associations were documented from accuracy assessment data, the remainder from vegetation plots, observation points, or field notes. 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. Polygons representing vegetation or land use map classes were delineated on-screen in an ArcView environment. The project used the program standard minimum mapping unit of 0.5 ha with few exceptions. The 18,633 map polygons representing 70 natural and semi-natural vegetation map classes cover 134,377 ha (332,053 acres, 91.6% of the project area). Map classes representing 1,720 polygons of unvegetated bedrock, talus, wash channels or sand sheets total 11,515 ha (28,454 acres; 7.8% of the project area). Nine map classes describing 634 polygons of land use categories, including roads, ranch developments and NPS facilities, total 862 ha (2,130 acres; 0.6% of the project area). Average polygon size across all map classes is 7.0 ha (17.3 acres). The most frequent vegetation map class is the Pinyon-Juniper / Mesic Shrubs Woodland Complex (Map Class 16 / W-PJME) with 5,122 polygons covering 42,197 ha (104,271) acres or 28.7% of the project area. Map accuracy was assessed within the CARE boundary only. Results from a thematic accuracy assessment of 44 vegetation map classes remaining after accuracy assessment analysis indicated an estimate of 77% overall map accuracy (Kappa statistic = 70%). Eleven map classes did not meet the 80% standard for either producer’s or user’s accuracy, but were retained because of their relative rarity and/or value to park managers. These map classes are described in detail in the Accuracy Assessment section of this report, along with the justification for retaining them.

Vegetation Classification and Mapping Project Report, Capitol Reef National Park [and associated files]

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