The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. All classification plot information sampled in 2009 was documented, summarized, and geo-processed into a GIS shapefile that could be overlain on the NAIP ortho-imagery. CTI created preliminary map classes (also known as map units) based largely on whether the vegetation surrounding the plot locations could be readily identified and delineated on the NAIP imagery (i.e. photo signature development). Once the photo signatures were inventoried they were matched or cross-walked back to the preliminary list of plant associations prepared in the project work plan. Supplemental land-use and land-cover classes (Anderson 1976, amended 2002) were added to classify non-vegetated areas such as developments, roads, streams, ponds, bare ground, and active agricultural areas. All obvious land-use features were manually digitized and incorporated with the project boundary into a draft GIS layer. Initial interpretation and mapping focused only on delineating obvious landforms (e.g., geologic exposures and land use) and physiognomic features (e.g., grasslands versus shrublands versus woodlands).

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. October 29, 1996: Aerial photography for Rock Creek Park is flown February 25, 1997: Initial meeting at Rock Creek Park headquarters - acquisition of aerial photography and ancillary data including existing vegetation maps March - April 1997: First cut delineations onto aerial photography of the photo signatures (see Figure 3 - Rock Creek Park Photo Index). May 12 - 16, 1997: Photointerpretation field reconnaissance trip, TNC training of park biologists in field sampling methodology May - June 1997: Develop initial list of photo signature types, Revise initial delineations based on field reconnaissance findings, Label existing polygons with photo signature types, Deliver copies of overlays to park biologists for plot selection and feedback June - September 1997: Park vegetation sampling effort February 19, 1998: Received draft TNC report of the vegetation classification for Rock Creek March 1998: Received final TNC report on the vegetation classification for Rock Creek, Received plot data and locations for vegetation sampling effort, Received TNC key for communities, Development of PI signature / TNC community lookup table, Polygons attributized with initial communities April 1998: Received DOQQ files (April 1989) May 11-12, 1998: Photointerpretation field verification trip May 1998: Revise photo signature / TNC community lookup table, Update and correct PI community calls and PI linework June - October 1998: Data rectification and conversion, Interim files and plots delivered to NPS-ROCR, Final documentation

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. October 29, 1996: Aerial photography for Rock Creek Park is flown February 25, 1997: Initial meeting at Rock Creek Park headquarters - acquisition of aerial photography and ancillary data including existing vegetation maps March - April 1997: First cut delineations onto aerial photography of the photo signatures (see Figure 3 - Rock Creek Park Photo Index). May 12 - 16, 1997: Photointerpretation field reconnaissance trip, TNC training of park biologists in field sampling methodology May - June 1997: Develop initial list of photo signature types, Revise initial delineations based on field reconnaissance findings, Label existing polygons with photo signature types, Deliver copies of overlays to park biologists for plot selection and feedback June - September 1997: Park vegetation sampling effort February 19, 1998: Received draft TNC report of the vegetation classification for Rock Creek March 1998: Received final TNC report on the vegetation classification for Rock Creek, Received plot data and locations for vegetation sampling effort, Received TNC key for communities, Development of PI signature / TNC community lookup table, Polygons attributized with initial communities April 1998: Received DOQQ files (April 1989) May 11-12, 1998: Photointerpretation field verification trip May 1998: Revise photo signature / TNC community lookup table, Update and correct PI community calls and PI linework June - October 1998: Data rectification and conversion, Interim files and plots delivered to NPS-ROCR, Final documentation

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. The map was designed to facilitate ecologically- based natural resources management at a 1:24,000 scale with 0.5-ha minimum map unit size. Based on a provisional assessment, overall accuracy was 82.5% for Level 1 and 66.8% for Level 2. Level 1 units will likely be sufficient and most appropriate for many natural resource planning and evaluations, while Level 2 units provide added fine-scale information within major ecological groups. To support the map as a management tool, we provide an annotated map legend along with descriptions of each plant association, a corresponding diagnostic key, field forms, and a plant species list. The map was delivered in both printed form and as digital Geographic Information System (GIS) map files. The GIS format 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.

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. The map was designed to facilitate ecologically- based natural resources management at a 1:24,000 scale with 0.5-ha minimum map unit size. Based on a provisional assessment, overall accuracy was 82.5% for Level 1 and 66.8% for Level 2. Level 1 units will likely be sufficient and most appropriate for many natural resource planning and evaluations, while Level 2 units provide added fine-scale information within major ecological groups. To support the map as a management tool, we provide an annotated map legend along with descriptions of each plant association, a corresponding diagnostic key, field forms, and a plant species list. The map was delivered in both printed form and as digital Geographic Information System (GIS) map files. The GIS format 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.

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. GRBA’s spatial database and map layer was produced from high-resolution 2007 Digital Map, Inc. imagery provided to CTI by the NPS. By comparing the signatures on the imagery to field and ground data, 64 map units (48 vegetated, four barren geology and snow, and 12 land-use / land-cover) were developed and the vegetation map units were directly cross-walked or matched to their corresponding rUSNVC plant associations. The interpreted and remotely sensed data were converted to Geographic Information System (GIS) spatial geodatabases and maps were printed, field tested, reviewed, and revised.

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. GRBA’s spatial database and map layer was produced from high-resolution 2007 Digital Map, Inc. imagery provided to CTI by the NPS. By comparing the signatures on the imagery to field and ground data, 64 map units (48 vegetated, four barren geology and snow, and 12 land-use / land-cover) were developed and the vegetation map units were directly cross-walked or matched to their corresponding rUSNVC plant associations. The interpreted and remotely sensed data were converted to Geographic Information System (GIS) spatial geodatabases and maps were printed, field tested, reviewed, and revised.

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. Just over 698 acres, including 214 acres in the authorized boundary of HOME and an additional 484 acres in the environs, were mapped using ten map classes (Figure 5). This included four land cover classes and six vegetation classes. Of all the map units, the most frequent was Fraxinus pennsylvanica / Ulmus spp. / Celtis occidentalis Forest with 21 polygons. Fraxinus pennsylvanica / Ulmus spp. / Celtis occidentalis Forest was also the most abundant map unit in terms of area other than cropfields in the environs, covering 219 acres (89 hectares) or about 13% of the project area. All of the frequencies for each map unit (i.e., number of polygons) along with acreage per map unit are listed in Table 3. Normally the standard minimum mapping unit for NPS vegetation mapping projects is defined as 0.5 hectare. However this is a nominal unit and due to the small size of HOME and the resolution of the imagery it was reduced to allow for more detail in the mapping. Therefore, 13 of the total 60 polygons were under 0.5 hectare. The average area of polygons for this project was 28.8 acres (11.6 hectares).

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. Just over 698 acres, including 214 acres in the authorized boundary of HOME and an additional 484 acres in the environs, were mapped using ten map classes (Figure 5). This included four land cover classes and six vegetation classes. Of all the map units, the most frequent was Fraxinus pennsylvanica / Ulmus spp. / Celtis occidentalis Forest with 21 polygons. Fraxinus pennsylvanica / Ulmus spp. / Celtis occidentalis Forest was also the most abundant map unit in terms of area other than cropfields in the environs, covering 219 acres (89 hectares) or about 13% of the project area. All of the frequencies for each map unit (i.e., number of polygons) along with acreage per map unit are listed in Table 3. Normally the standard minimum mapping unit for NPS vegetation mapping projects is defined as 0.5 hectare. However this is a nominal unit and due to the small size of HOME and the resolution of the imagery it was reduced to allow for more detail in the mapping. Therefore, 13 of the total 60 polygons were under 0.5 hectare. The average area of polygons for this project was 28.8 acres (11.6 hectares).

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. The mapping component of the BRCA project used a combination of methods to interpret and delineate vegetation and land use polygons. The USGS applied an electronic segmentation method (e-Cognition software) to create preliminary linework on features with high-contrast photo-signatures. Using the preliminary linework as a baseline starting point, the primary photointerpreter drew polygons directly on screen through heads-up digitizing using ArcGIS editing tools. Additionally, trained photointerpreters assisting the primary photointerpreter drew polygons on Mylar overlays covering 1m resolution, 1:12,000-scale, 9 x 9-inch true-color aerial photographs. This process enabled the photointerpreters to view the landscape in stereo in order to identify finer details. The linework drawn on Mylar overlays was then transferred into digital media by heads-up digitizing using ArcGIS software. The park and environs were interpreted and mapped to the same level of detail.