This geospatial dataset contains North Coast and Cascades Network (NCCN) prairie vegetation monitoring spatial data collected during 2007-2017 at in San Juan Island National Historical Park (SAJH). The protocol, publications, and all other associated links can be found in the project reference NCCN Monitoring Prairie Vegetation: https://irma.nps.gov/DataStore/Reference/Profile/2193720 Geodatabase feature classes include the original Generalized Random Tessellation Stratified (GRTS) transects, modified active transects selected from the GRTS feature class, and annual segments with associated vegetation data 2007-2009, 2012-2015, and 2017. The goal of the NCCN prairie monitoring program is to detect and describe changes in the extent and quality of prairie communities in San Juan Island National Historical Park (SAJH). SAJH protects some of the last remaining prairies in Washington state. Over 60% of the American Camp unit is dominated by grasslands that have persisted since the end of the Pleistocene. In 2007, the National Park Service initiated monitoring to document status and trends in cover and ecological condition of vegetation communities using repeatable, rapid assessment of physiognomic class and vegetation quality along line-intercept belt transects. Transect-based sampling was designed to address a hierarchy of monitoring questions linked to management objectives, including the maintenance of broad landscape structure (e.g., forest versus herbaceous) associated with the cultural landscape and the continued ecological integrity of plant communities. While physiognomic cover is similar today to the historic time period (36% forest:61% non-forest), the ecological condition of grasslands or prairies is threatened by persistent, introduced grasses and exotic shrubs. Monitoring objectives included: 1) detect change in the extent of physiognomic cover types, 2) detect change in the proportion of areas dominated by exotic plant species, 3) detect change in the quality of herbaceous cover types, and 4) detect changes in composition and diversity of herbaceous cover types. Monitoring was implemented at the American Camp unit of SAJH, since 90% of all prairies are located within this section of the park.

This data package contains North Coast and Cascades Network (NCCN) Inventory and Monitoring Program prairie vegetation monitoring tabular data collected during 2007-2017 at the American Camp Unit of San Juan Island National Historical Park (SAJH). The protocol, publications, and all other associated links can be found in the NCCN Monitoring Prairie Vegetation project reference at: https://irma.nps.gov/DataStore/Reference/Profile/2193720 San Juan Island National Historical Park protects some of the last remaining prairies in Washington state. Over 60% of the American Camp unit is dominated by grasslands that have persisted since the end of the Pleistocene. In 2007, the National Park Service initiated monitoring to document status and trends in cover and ecological condition of vegetation communities using repeatable, rapid assessment of physiognomic class and vegetation quality along line-intercept belt transects. Transect-based sampling was designed to address a hierarchy of monitoring questions linked to management objectives, including the maintenance of the vegetation structure (e.g., forest versus herbaceous) associated with the cultural landscape and the continued ecological integrity of plant communities. The ecological condition of prairies is threatened by persistent, introduced grasses and exotic shrubs. Monitoring objectives included: 1) detect change in the extent of physiognomic cover types, 2) detect change in the proportion of areas dominated by exotic plant species, 3) detect change in the quality of herbaceous cover types, and 4) detect changes in composition and diversity of herbaceous cover types. Monitoring was implemented at the American Camp unit of SAJH, since 90% of all prairies are located within this section of the park. Transects proved to be an economical and reliable method for monitoring long-term trends in landscape cover with transient crews, but detailed vegetation monitoring (i.e., species frequency and relative abundance) is needed to better assess prairie condition over time. Data within this package include point sampling locations, sampling effort and conditions, transect vegetation structure data, and phenological observations. The associated spatial transect lines and segments can be found at https://irma.nps.gov/DataStore/Reference/Profile/2305031.

Vascular plant inventory tabular data for San Juan Island National Historical Park, 2001-2006. The objectives of the vascular plant inventories were: 1) to compile a vascular plant list for the park, 2) to verify the occurrence of at least 90% of the species through written records or voucher specimens, and 3) to describe prairie communities of American Camp. Vascular plant inventories were conducted within San Juan Island National Historical Park between 2001 and 2005. The objectives of the vascular plant inventories were: 1) to compile a vascular plant list for the park, 2) to verify the occurrence of at least 90% of the species through written records or voucher specimens, and 3) to describe prairie communities of American Camp. Native species comprised 67% (268 species) of the total (400) and 70% of all species are perennial. The ratio of annual/biennial to perennial species varies greatly between native species and exotics. Approximately 17% of all native species are annuals or biennials while 57% of exotics are in this category. Three species, Symphotrichum hallii, Crassula connata, and Ranunculus californicus, documented within SAJH are listed as threatened by the Washington Natural Heritage Program. Prairie plant communities at American Camp were inventoried using 1 m2 plots distributed randomly within five herbaceous communities described by Peterson (2002) and polygons that were delineated during the inventory as areas dominated by native species. Surveys were also conducted of soil seed banks to inform development of prescriptions for future restoration programs. Twelve plant communities were described including five that were dominated by native plant species: the Festuca roemeri (Roemer’s fescue) community, the Leymus mollis-Holcus lanatus (dune grass-velvet grass), Juncus balticus-Schedonorus pratensis-Juncus effuses (Baltic rush-meadow fescue-lamp rush), Lupinus littoralis-Bromus rigidus (seashore lupine-ripgut brome), Bromus sitchensis-Bromus hordeaceus-Poa pratensis (Sitka brome-ripgut brome-Kentucky bluegrass), and the Abronia latifolia (coastal sand verbena) communities. Five exotic species dominated the seedlings that emerged from soil samples in the greenhouse: Rumex acestosella, Holcus lanatus, Myosotis discolor, Aira caryophylla, and A. praecox. These species were found in all communities and did not reflect species that dominated the above-ground community.

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. Polygons were assigned map class number and name. The vegetation community polygons and other related and supporting data were then incorporated into a geodatabase format. The data recorded on the field forms were subsequently entered into the PLOTS database and reviewed for data entry errors by Kansas Natural Heritage Inventory staff. The results were imported from the database into a GIS layer where they were visually compared in two stages to the vegetation map coverage.

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. Polygons were assigned map class number and name. The vegetation community polygons and other related and supporting data were then incorporated into a geodatabase format. The data recorded on the field forms were subsequently entered into the PLOTS database and reviewed for data entry errors by Kansas Natural Heritage Inventory staff. The results were imported from the database into a GIS layer where they were visually compared in two stages to the vegetation map coverage.

This reference contains the imagery data used in the completion of the baseline vegetation inventory project for the NPS park unit. Orthophotos, raw imagery, and scanned aerial photos are common files held here. The mapping component was initiated by photo interpretation and digitization of 4-band 2005 IKONOS imagery for the vegetation and land use classes determined through the field visit and expert knowledge of project team members. The heads-up digitization was performed at a display scale of 1:1500 to 1:2000. The digitization, evaluation, and modifications comprised an iterative and collaborative process involving the GIS analysts and the rest of the team. Preliminary maps were checked, corrected, and rechecked for boundary delineations. These image sources included 2003, 2004, 2005, 2006 (3-band, Red, Green, Blue), and 2008 (4-band, Red, Green, Blue, Near Infrared) USDA FSA NAIP, 2002 and 1991 USGS DOQQs, and 1938 panchromatic imagery. Two additional 4-band (Red, Green, Blue, Near Infrared) IKONOS scenes were acquired in June and September of 2008 specifically for this project. These IKONOS image acquisitions targeted specific phenological windows that were generally not covered by other imagery.