A vegetation classification and map: Capulin Volcano National Monument

Muldavin, Esteban; Chauvin, Yvonne; Neville, Teri; Paul, Arbetan; Fettes, Anthony; Neville, Paul; Bennetts, Rob

A vegetation classification and high-resolution vegetation maps were developed for Capulin Volcano National Monument, New Mexico as part of the U.S. Geological Survey (USGS) National Park Service (NPS) National Vegetation Mapping Program. The monument is located in the northeastern plains of New Mexico (southeast of Raton) and is 315.7 ha (780 ac) in size. While known for its geologic features, the park supports a relatively high diversity of habitats for wildlife and plants not found elsewhere in the surrounding grassland. Accordingly, the vegetation ranges from ponderosa pine and piñon-juniper woodlands to the montane shrubland and grasslands of the volcano, surrounding a mixture of grassland communities at the base and extending out into the prairie. We identified 24 plant associations from among nine vegetation groups following the National Vegetation Classification Standard (NVCS). These in turn were used to define a suite of vegetation map units. The vegetation map was developed using a combination of automated digital processing (supervised classifications and image segmentation) and direct image interpretation of high-resolution color aerial ortho-photography in combination with satellite imagery (DigitalGlobe QuickBird). The map was designed to facilitate ecologically based natural resources management at a 1:6,000 scale with a 0.5-ha minimum map unit size. The map legend was hierarchically structured with an upper Level 1 of 11 map units, nine of which correspond to the Group Level NVCS and two are miscellaneous land-use classes. These include: Southern Rocky Mountain Ponderosa Pine Forest and Woodland, Southern Rocky Mountain Piñon-Juniper Woodland, Southern Rocky Mountain Gambel Oak-Mixed [Mesic] Montane Shrubland, Southern Rocky Mountain Cercocarpus-Mixed [Dry] Foothill Shrubland, Southern Rocky Mountain Montane-Subalpine Grassland, Southwest Plains-Mesa Mixedgrass Prairie, Southwest Plains-Mesa Grassland, Southwest Ruderal Shrubland and Grassland, and Southwest Cliff, Scree and Rock Vegetation. Level 2 is a further refinement composed of 18 nested map units defined by specific plant associations in the vegetation classification that reflect variations in plant community structure as well as species composition within the broader Level 1units. Overall accuracy at Level 1 was estimated at 83% and 67% at Level 2. For many natural resource management applications, Level 1 units will likely be sufficient and most appropriate, while Level 2 units provide added fine-scale information within major ecological groups. To support the map as a management tool, an annotated map legend is provided along with descriptions of each plant association, a corresponding diagnostic key, field forms, and a plant species list. The map was delivered in both hard copy and digital form as part of a geographic information system (GIS) compatible with that used in the park and the USGS NPS mapping program. The GIS allows flexibility to update the map as new information becomes available or as major vegetation changes, such as fire, disease or other impacts, occur in the park.