Vegetation Classification and Mapping Project Report, Dinosaur National Monument

Coles, Janet; Cogan, Dan; Salas, David; Wight, Aneth; Wakefield, Gery; Von Loh, Jim; 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 Dinosaur National Monument (DINO). This collaborative effort involved many project partners, particularly the Remote Sensing and Geographic Information Group of the U.S. Bureau of Reclamation, the Western Region office of NatureServe, engineeringenvironmental Management, Inc., and their cooperators.The mapping area is 161,169 hectares (398,258 acres), encompassing the entire monument as well as an environs of adjacent public and private lands. Ecologists and photointerpreters worked together to identify plant associations for DINO 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 727 vegetation classification plots and 217 observation points. Supplemental fuels data were collected during the project in sagebrush, pinyon-juniper, ponderosa pine, and Douglas-fir communities. Assessment of map accuracy entailed sampling of another 1,543 data points. Fieldwork and mapping were completed between 2002 and 2005.Analysis of the plot data revealed 174 National Vegetation Classification plant associations, alliances, or park special vegetation types within the monument and environs. Eighteen associations were documented from accuracy assessment data, the remainder from vegetation plots, observation points, and 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 Mylar overlays on paper plots of the orthophotographs and transferred to a spatial database. The project used the program standard minimum mapping unit of 0.5 ha with few exceptions.The DINO vegetation mapping project area was 161,169 ha (398,258 acres) divided into 31,384 polygons. A total of 28,915 map polygons represent 37 natural and semi-natural vegetation map classes. Nine land use map classes describe 372 other polygons within the mapping area. An additional 2,097 polygons represent exposures of unvegetated geological formations. Average polygon size across all map classes is 5.1 ha (12.7 acres). Natural and semi-natural vegetation classes cover 153,963 ha (380,449 acres; 95.5% of the project area). Map classes representing unvegetated bedrock, talus or washes total 5,672 ha (14,015 acres; 3.5% of the project area). Land use/land cover polygons, including roads, ranch developments and NPS facilities, total 1,536 ha (3,794 acres; 1% of the project area). The most frequent vegetation mapping unit is the Sagebrush - Rabbitbrush Shrubland (S-SAGE, #31) with 5,368 polygons covering 31,695 ha (78,320 acres) or 19.7% of the project area.Map accuracy was assessed within the DINO boundary only. Results from a thematic accuracy assessment of 37 vegetation map classes remaining after accuracy assessment analysis indicated an estimate of 81% overall map accuracy (Kappa statistic = 79%). Seven 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 monument managers. These map classes are described in the Accuracy Assessment section of this report, along with the justification for retaining them.

Vegetation Classification and Mapping Project Report, Dinosaur National Monument

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