Vegetation Classification and Mapping Project Report, Washita Battlefield National Historic Site

Cogan, Dan

Washita Battlefield National Historic Park (WABA) encompasses approximately 315 acres in the Osage and High Plains section of western Oklahoma, approximately 2 miles west of Cheyenne, OK and 20 miles east of the Texas border (halfway between Amarillo, Texas and Oklahoma City, Oklahoma). This unique site preserves the location of a tragic battle between the Southern Cheyenne Tribe and the U.S. Calvary occurring in 1868. The vegetation at this site is in flux due to past agricultural and cultural activities such as clearing for farming, grazing, a railroad right-of-way and past homestead sites. Although non-native plants are present, the park is actively controlling them through removal and native prairie restoration. Intermixed with these types are stable, remnant native plant populations occurring in the riparian corridors and on the rocky hilltops. To better understand the distribution of these plant assemblages the NPS Southern Plains Inventory and Monitoring Network (SOPN) started a vegetation mapping and classification effort at WABA in 2005.A three-year program was initiated to complete the task of mapping and classifying the vegetation at WABA. Phase one, directed by the Botanical Research Institute of Texas (BRIT) in conjunction with NatureServe developed a vegetation classification using the National Vegetation Classification System (NVCS). Phase two, directed by the U.S. Bureau of Reclamation’s (BOR) Remote Sensing and Geographic Information Group in conjunction with Cogan Technology, Inc (CTI) produced a digital vegetation map. To classify the vegetation, 31 representative plots located throughout the approximately 924 acre project area (park + environs) were sampled during the summer of 2005. Analysis of the plot data by NatureServe in the winter of 2005-2006 produced 11 distinct plant associations and alliances. One of which was newly described in the National Vegetation Classification (NVC). In addition, CTI described 4 more alliances, 1 more association and 4 distinctive stands of vegetation (i.e. Park Specials) that primarily occurred as small stands in the park or were located outside of the park in the environs. Descriptions and a field key for all 20 unique plant assemblages for WABA are included in this report.To produce the digital map, a combination of 1:12,000-scale true color digital ortho-imagery acquired in 2003, 1:12,000-scale true color ortho-rectified imagery acquired in 2005, and all of the GPS referenced ground data were used to interpret the complex patterns of vegetation and land-use. In the end, 27 map units were developed and directly cross-walked or matched to corresponding plant associations/alliances and land-use classes. All of the interpreted and remotely sensed data were converted to Geographic Information System (GIS) databases using ArcGIS© software. One hundred and five accuracy assessment (AA) data points were collected in 2006 and used to determine the map’s accuracy.

Vegetation Classification and Mapping Project Report, Washita Battlefield National Historic Site

Series