Vegetation classification and distribution mapping report: El Morro National Monument

Salas, David; Bolen, Cory

El Morro National Monument (ELMO) encompasses approximately 419.4 ha (1,036 acres) in westcentral New Mexico. The park is bounded by a variety of public and privately owned lands, and protected from grazing. The vegetation is represented by roughly 400 species of vascular plants (Rink et al. 2009) in a limited set of communities representing pinyon-juniper woodlands, ponderosa-pine woodlands, blue-grama grasslands, four-winged saltbush shrublands, and some Gambel-oak shrublands. In 2005, this project was initiated to map the vegetation and develop a classification for the plant communities in the study area. The ELMO vegetation inventory was conducted in accordance with the following protocols and standards specified by the USGS-NPS Vegetation Mapping Program: Nationally defined standards 1. National Vegetation Classification Standard 2. Spatial Data Transfer Standard 3. Metadata Standard 4. Positional Accuracy 5. Taxonomy Additional program-defined standards 6. Classification Accuracy 7. Minimum Mapping Unit This report documents those efforts. A multi-year program was initiated to complete vegetation mapping at ELMO, consisting of two major tasks. Phase I was the development of a classification system. Phase II was the production of a digital vegetation map. Prior work by Dr. Anne Cully was used as base information for the classification. Additional data was collected to expand upon the vegetation types at ELMO. The described types are based on the floristic alliance and association units maintained by NatureServe (U.S. National Vegetation Classification; NVC). To classify vegetation, we used 32 plots collected by Anne Cully in 2001, in addition to 47 observation points collected in 2005. These plots were compared to existing vegetation types within the NVC and assigned an appropriate type. A total of 22 plant-association descriptions are detailed in this report. From these 22 plant associations, we derived 18 vegetation map units. An additional two map units show bare rock and other unvegetated surfaces, such as roads and buildings, and one is a “Weedy Forbs/Prairie Dog Colony” map unit. To produce the digital map, we used 1:12,000-scale, true-color aerial photography acquired on September 1, 2004, in addition to the field plots. Both avenues were used to interpret the vegetation. All 21 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 ArcGIS© software. Draft maps were printed, reviewed, and revised.

Vegetation classification and distribution mapping report: El Morro National Monument

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