Vegetation Classification and Mapping Report: Aztec Ruins National Monument [and associated files]

Salas, David; Wegner, Dave; Floyd-Hanna, Lisa

Aztec Ruins National Monument (AZRU) encompasses approximately 130 ha in northwest New Mexico. Terrain varies from a low of approximately 1,716 m (5,630 ft) at the Animas River to an elevation of approximately 1,774 m (5,820 ft). AZRU is located within San Juan County, New Mexico, and lies at the lower end of the Animas River valley, south of the La Plata Mountains of southwest Colorado. This mapping effort is part of the National Park Service’s National Inventory and Monitoring (I&M) Program, and will provide core, or “baseline” information that park managers need to eff ectively manage and protect park resources. The AZRU vegetation inventory was conducted in accordance with the following protocols and standards specified by the U.S. Geological Survey/National Park Service Vegetation Mapping Program. This work is a natural extension of earlier work that reported 100 species of plants in communities representing uplands, riparian zones, and urban interfaces. In 2005, this project began to develop classification and mapping of the plant communities in the study area. This report documents those eff orts and includes an updated list of plant species. This project was directed by the U.S. Bureau of Reclamation’s Remote Sensing and Geographic Information Group, based in Denver, Colorado. The goals of the project were twofold: one, to describe the current vegetation, and two, to provide a digital vegetation map. To classify the vegetation, 18 representative plots were located throughout the approximately 130-ha project area. These plots were sampled during the summer and fall of 2006. Analysis of the plot data showed 14 distinct National Vegetation Classification (NVC) plant associations. The 14 plant-association descriptions are included in this report. A total of 28 map units were used to describe the project area. Fourteen map units represent the NVC associations. Of the remaining 14 map units, 4 are vegetated but represent either park picnic-area, agricultural, or weedy map units/land-cover types that do not fit into the NVC. The remaining 10 are non-vegetated land-cover types such as industrial, commercial, or urban areas. To produce the digital map, we used existing 0.3-m-pixel imagery (color, color infrared, and panchromatic) acquired in 2003. This imagery did not cover the entire project area completely; therefore, we filled in the missing area with a 1998 U.S. Geological Survey 1-m-pixel, digital orthophoto quadrangle map. These images, in addition to ground-truthing, were used to interpret patterns of vegetation and land use. All of the interpreted and remotely sensed data were converted to geodatabases using ARCGIS© software. Draft maps were printed, fi eld-verified, reviewed, and revised as necessary. Due to the small size of AZRU, each point collected was revisited, resulting in a 100%-accuracy assessment of the evaluated area.

Vegetation Classification and Mapping Report: Aztec Ruins National Monument [and associated files]

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