Vegetation inventory, mapping and characterization report, Montezuma Castle National Monument: Castle and Well units

Studd, Sarah; Galvin, Jeff; Buckley, Steve

From 2009 to 2014, the Sonoran Desert Network conducted a vegetation mapping and characterization effort at Montezuma Castle National Monument (NM), in collaboration with researchers from the University of Arizona’s Office of Arid Lands Studies. This effort was completed under the National Park Service (NPS) Vegetation Mapping Inventory, which aims to complete baseline mapping inventories at over 270 NPS units. The goal of the project was to provide park managers with a digital map product that meets national standards of spatial and thematic accuracy, while also placing park vegetation into a regional and national context. The data standard was designed to facilitate the production of uniform statistics about vegetation across the nation, enable the translation of data collected at various scales, and allow data sharing, aggregation, and comparison across regions. Vegetation mapping and characterization comprised three major field phases: (1) concur-rent, field-based data collection and mapping from aerial imagery (map unit delineation), (2) development of vegetation community types at the National Vegetation Classification (NVC) association level, and (3) map accuracy assessment. Phase 1 was completed in late 2008 and early 2009. Community-type descriptions were drafted to meet the NVC standard and ap-plied to each mapped area. This classification was developed concurrently from plot data and field-censused polygon data (map units). Network staff conducted a thematic accuracy check in spring 2014. This check provided useful information that improved both the detail of the association descriptions and the accuracy of the mapped polygons. Staff conducted a thematic validation check in Spiring 2014. In the accuracy assessment, plots were distributed proportionally within each vegetation type and sampled by a separate team in an unbiased manner. Following accuracy assessment, final products were developed. Those products include this report, a digital map, and full vegetation descriptions. Montezuma Castle NM covers only 1,000 acres, but its landscape, topography, and geology are relatively complex. A total of 12 distinct communities (10 at the Castle unit and 9 at the Well unit) were described and mapped at the park. These ranged from lush riparian wood-lands of Arizona sycamore (Platanus wrightii) and velvet ash (Fraxinus velutina) along Beaver Creek to velvet mesquite (Prosopis velutina) bosques and drier upland sites of crucifixion thorn (Canotia holocantha). These communities boast a diverse mixture of shrubs, succu-lents, and perennial grasses, with influences of the both the Colorado Plateau and the Basin and Range provinces. A total of 226 different plant species were recorded during the project. Overall accuracy for all map classes was 89.7% (90% CI: 86.2, 93.3) with a Kappa (a measure of overall accuracy minus chance agreement) of 88.4% (90% CI: 84.3, 92.4). Individual ac-curacies ranged from 46.9% to 100%. Only two of the 12 vegetation types were “accepted” types within the NVC. The others, described here as specific to the park, are currently proposed for formal status within the NVC. The map was designed to facilitate ecologically based natural-resource management and research. The vector (polygon) map is in digital format within a geodatabase structure that allows for complex relationships to be established between spatial and tabular data, and makes accessing the product easy and seamless. The GIS format allows user flexibility and will also enable updates to be made as new information becomes available (such as revised NVC codes or vegetation type names), or in the event of major disturbance events that could impact the vegetation.

Vegetation inventory, mapping and characterization report, Montezuma Castle National Monument: Castle and Well units

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