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Vegetation Community Classification and Mapping of the INL Site

The INL Site vegetation map is a dynamic dataset that may be updated periodically. It is the user's responsibility to insure the most recent dataset is being used. Please contact Jeremy Shive (jeremy.shive@inl.gov) to inquire about any recent updates to the dataset. Note: The INL Site vegetation map was completed before the Sheep Fire burned in 2019. This region of the map will need to be updated when appropriate field data and recent imagery are available.

Over the past decade, the vegetation map has become one of ESER’s most important datasets and is used to support nearly every other ecologically based task.

  • Support inventory and monitoring of ecological resources on the INL Site.
  • Identify and prioritize potential habitat for sensitive species.
  • Identify restoration and/or weed control opportunities.
  • Characterize affected environments for NEPA analyses

Because the vegetation map is integral to the ESER Program, it is important to update the map periodically to ensure that both the vegetation classes identified on the INL Site and the mapped boundaries of those classes remain accurate. In 2017, the process of creating an updated map of the INL began. The goal of this project is to develop an updated vegetation classification and map of the current distribution of plant communities on the INL Site. Our specific objectives included: 1) characterize the vegetation community types present on the INL Site; 2) define the spatial distribution of those community types; and 3) conduct a quantitative accuracy assessment of the resulting map.

Objective 1 – Plant Community Classification

The primary objective of the plant community classification was to sample a representative range of plant communities across the INL Site and organize them into meaningful vegetation classes.

The vegetation class list is organized and interpreted within the context of the National Vegetation Classification (NVC). Of the 16 vegetation classes identified in the INL Site classification:

  • Twelve are natural vegetation classes:
    • One woodland class
    • Six shrubland class
    • Two shrub glasslands
    • Two grasslands
  • Four are ruderal classes (dominated by non-native species):
    • One shrubland
    • Two grasslands
    • One characterized by mixed weedy forbs that tend to dominate areas with a specific hydrologic regime, namely playas.

Objective 2 - Vegetation Class Delineations and Mapping

The updated INL Site vegetation map contains 7,637 polygons, of which 7,265 (95.1%) represent vegetation classes. The remaining 372 (4.9%) polygons were assigned to nonvegetation special classes that accounted for only 30.3 km2 (7,478.8 acres) of the total mapped area.

  • Big Sagebrush – Green Rabbitbrush (Threetip Sagebrush) Shrubland class contained the largest amount of total area mapped with 851.2 km2 (210,330.9 acres).
  • The second largest class mapped was the Green Rabbitbrush / Thickspike Wheatgrass Shrub Grassland and Needle and Thread Grassland class with 570.8 km2 (141,035 acres).

The three largest map classes cover 73.2% of the vegetated area on the INL Site, suggesting the majority of vegetation communities are dominated by big sagebrush (Artemisia tridentata) or species most commonly associated with post-fire communities where big sagebrush was previously present.

Objective 3 - Vegetation Map Accuracy Assessment

During the summer of 2018, a total of 453 independent validation plots were collected and used to support the accuracy assessment of the final vegetation map.

The accuracy assessment results showed an overall map accuracy of 77.3%.

  • Juniper Woodland had the highest user’s and producer’s accuracy at 100%.
  • Big Sagebrush – Green Rabbitbrush (Threetip Sagebrush) Shrubland and Big Sagebrush Shrubland class had 93.9% accuracy.
  • Five other classes had a user’s accuracy above 80%.

Vegetation and Community Classification and Mapping Reports

Juniper Woodlands: Class 11

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