Zion National Park (ZION) encompasses 229 square miles in Southwest Utah, stretching across portions of the Colorado Plateau, Great Basin, and Mojave Desert regions of the United States. Between 1999 and 2003 an ambitious project was conducted to accurately classify and map ZION’s unique assemblage of plant associations. This report documents those efforts.
To complete the daunting task of mapping the diverse vegetation at ZION, a multi-year program was initiated. This consisted of two linked phases: (1) vegetation classification using the National Vegetation Classification System (NVCS) and (2) digital vegetation map production directed by NatureServe and the U.S. Bureau of Reclamation’s (BOR) Remote Sensing and GIS group, respectively. To classify the vegetation, we sampled 346 representative plots located throughout the 246,452-acre (99,738 ha) project area (park + environs) during the summers of 1999 and 2000. Analysis of the plot data using ordination and clustering techniques produced 95 distinct plant associations, 44 of which were newly described at ZION.
To produce the digital map, we used a combination of 1999 1:12,000-scale true color aerial photography, 1999 1:12,000-scale true color ortho-rectified imagery, and 3 years of ground-truthing to interpret the complex patterns of vegetation and land-use at ZION. In the end, 76 map units were developed and directly cross-walked or matched to corresponding plant associations and land-use classes. All of the interpreted and remotely sensed data were converted to Geographic Information System (GIS) databases using ArcInfo© software. Draft maps created from the vegetation classification were field-tested and revised before independent ecologists conducted an assessment of the map’s accuracy during 2001-2003. The accuracy assessment revealed an overall database accuracy of 82%.
Products developed for Zion National Park are described and presented in this report and are stored on the accompanying CD-Rom, these include:
• A Final Report that includes a vegetation key, accuracy assessment information, and a photo interpretation key
• A Spatial Database containing vegetation, plots, accuracy assessment, and flight line index layers
• Digital Photos (scanned from 35mm slides) of each vegetation type along with representative ground photos and miscellaneous Park views
• Printable Graphics of all spatial database coverages
• Federal Geographic Data Committee-compliant metadata for all spatial database coverages and field data.
