Vegetation classification and mapping at Saint-Gaudens National Historic Site, New Hampshire.

Gawler, Susan; Bowman, Peter

Vegetation mapping of Saint-Gaudens National Historic Site follows established National Park Service (NPS) protocols under its umbrella agreement with NatureServe and its component network of natural heritage programs. After a scoping session with park staff and field reconnaissance, we developed an initial vegetation classification for Saint-Gaudens NHS based on NatureServe's U.S. National Vegetation Classification (USNVC) and the New Hampshire Natural Heritage Inventory's state types. Twenty-five vegetation plots were sampled in the summer of 2004, covering the range of variation in the vegetation. Plot sampling included information on vegetation structure, composition and individual species cover by vegetation stratum, and environmental setting. Analysis of the plot data and field notes allowed us to finalize the vegetation classification for the park and to map these classes onto an orthorectified composite aerial photo background using on-screen digitizing. Seventeen accuracy assessment points were collected to verify the accuracy of the vegetation map. The overall map accuracy and Kappa index from the accuracy assessment is 86.5%. Twelve USNVC vegetation associations are described for Saint-Gaudens National Historic Site. Four upland forests are described. The most common forest type within the park is Hemlock - Beech - Oak - Pine Forest, with smaller areas of Semi-rich Northern Hardwood Forest, Hemlock - White Pine Forest, and Successional White Pine Forest. Small Enriched Hardwood Forest Seeps occur as small patches within some of the upland forest associations. Riparian and herbaceous wetland associations are concentrated on the western periphery of the park in association with Blow-Me-Down Pond and Blow-Me-Down Brook. Successional Old Fields occur to the west and northeast of the Saint-Gaudens house. Managed or built-up areas around the home and grounds were classified according to the Anderson Level II (modified) land use classification. Nonnative plant species that occurred in or near the plots were noted. Detailed descriptions of the local and global expressions of each vegetation association, a field key to vegetation types, a plant species list derived from the plots and accuracy assessment points, metadata for the vegetation map and the plot data, and an index to photographic documentation are included as appendices to this report. Shapefiles of the digital vegetation map, the spatial locations of plot and accuracy assessment points, and the digital orthophoto developed for Saint-Gaudens National Historic Site are also deliverables of this project.

Vegetation classification and mapping at Saint-Gaudens National Historic Site, New Hampshire.

Series

Collections