Vegetation classification and mapping project report, Cedar Breaks National Monument [and associated files]

Tendick, Amy; Friesen, Beverly; Kittel, Gwen; Williams, Peter; Coles, Janet; Wight, Aneth; Wakefield, Gery; Evenden, Angie

The Northern Colorado Plateau Inventory and Monitoring Network cooperated with the U.S. Geological Survey - National Park Service Vegetation Mapping Program to describe and map vegetation at Cedar Breaks National Monument (CEBR). This collaborative effort involved many project partners, particularly the Rocky Mountain Geographic Science Center of the U.S. Geological Survey, the Western Region office of NatureServe, engineering-environmental Management, Inc., and their cooperators. The mapping area includes approximately 4,840 hectares (11,960 acres), encompassing the entire monument as well as an environs of adjacent public and private lands. Ecologists and photo interpreters identified plant associations within CEBR and determined an effective mapping approach using 1:12,000-scale, true color aerial photography and digital orthophotography. Field crews collected vegetation and environmental data from 172 vegetation classification plots and 110 observation points in 2006 to prepare the initial classification and vegetation map. During July 24-27, 2007, the primary photo interpreter conducted a vegetation map verification trip and updated the draft map using the resultant recommendations prior to full-scale accuracy assessment. Assessment of CEBR vegetation map accuracy entailed random selection and sampling an additional 303 data plots in the late summer of 2007. Analysis of the classification plot and accuracy assessment plot data revealed 71 National Vegetation Classification plant associations, vegetation alliances, or park special vegetation types within CEBR and environs. Sixteen plant associations were documented exclusively from accuracy assessment data, the remainder from vegetation classification plots and observation points. Vegetation and land use mapping units 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. A combination of methods was used to delineate and interpret vegetation polygons for the mapping component of the CEBR project area, including the use of ERDAS Imagine software facilitated by heads-up (on-screen) digitizing. The project used the program standard minimum mapping unit of 0.5 ha (1.24 acres) with few exceptions. Twenty-six map classes were developed and interpreted for CEBR, resulting in 1,253 polygons. A total of 1,195 polygons represent 20 natural or semi-natural vegetation map classes covering 82% of the mapping project area. Six land use/land cover and geologic map classes describe 58 polygons (5% of polygons and 18% of the area). Average polygon size across all map classes is 4.7 ha (11.6 acres). Lands within CEBR make up 2,481 ha (6,130 acres) or 51% of the total project area. The most common map class is Subalpine fir - Engelmann Spruce Forest Complex with 240 polygons covering 25.6% of the mapping area. Map accuracy was assessed within the CEBR boundary only. Primary analyses of the field data were presented and evaluated at an accuracy assessment meeting held from December 4-5, 2007. Results from a thematic accuracy assessment of 20 vegetation map classes remaining after accuracy assessment analysis indicated an estimate of 88.1% overall map accuracy (Kappa statistic = 87.1%). Six 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 the Accuracy Assessment section of this report, as is the justification for retaining them.

Vegetation classification and mapping project report, Cedar Breaks National Monument [and associated files]

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