Vegetation Classification and Mapping at Gettysburg National Military Park and Eisenhower National Historic Site

Perles, Stephanie; Podniesinski, Gregory; Millinor, William; Sneddon, Lesley

Vegetation classification and mapping was conducted at Gettysburg National Military Park and Eisenhower National Historic Site, creating a current digital geospatial vegetation database for the parks. Classification and mapping was completed jointly for these two parks because the parks are geographically contiguous and are managed by the same natural and cultural resource personnel. Fifteen vegetation associations, Chestnut Oak Forest, Dry Oak – Mixed Hardwood Forest, Tuliptree Forest, Modified Successional Forest, Conifer Plantation, Virginia Pine Successional Forest, Sycamore – Mixed Hardwood Floodplain Forest, Bottomland Mixed Hardwood Forest, Palustrine Shrub Thicket, Successional Old Field, Agricultural Field, Pasture, Orchard, Wet Meadow, and Reed Canary Grass Riverine Grassland, that occur within the parks were identified and described in detail. These vegetation types are strongly influenced by the varied environmental settings of the parks and the mandate to preserve the topographic, landscape, and cultural features as they were in 1863, such that visitors and historians can fully understand and appreciate the Battle of Gettysburg. A map showing the locations of vegetation associations in the parks was created following the USGS/NPS Vegetation Mapping Program protocols (The Nature Conservancy and Environmental Systems Research Institute 1994a, b, c). These vegetation associations were also crosswalked to the Terrestrial and Palustrine Plant Communities of Pennsylvania (Fike 1999) and to the National Vegetation Classification System in order to provide a regional and global context for the parks’ vegetation. A dichotomous field key was developed for these vegetation associations to assist with field recognition and classification. This project documents the vegetation associations of Gettysburg National Military Park and Eisenhower National Historic Site based on 2003 aerial photography and 2004 field sampling, and completes one of 12 basic inventory data sets for the parks. However, battlefield rehabilitation in Gettysburg National Military Park has significantly altered the vegetation in many sections of the park; so much so, that the vegetation map was significantly out of date even before this report was published. Therefore, once the battlefield rehabilitation is completed, a new map of the vegetation associations should be completed based on the classification work presented in this report.