Vegetation Community Classification and Mapping at the INL Site

INL Vegetation MapObjectives: The goal of the vegetation community classification and mapping project is to develop an updated vegetation map detailing the distribution of plant communities on the INL Site. Specific objectives are to:

  • Characterize the vegetation community types present on the INL Site
  • Define the spatial distribution of those community types
  • Conduct a quantitative accuracy assessment of the resulting map.


The approach is based on a process developed by the U.S. Geological Survey and National Park Service for use in land management planning and includes two parallel tasks, plant community classification and map unit delineation. Plant community classification entails multivariate analysis of applicable historical vegetation data sets and a current project-specific vegetation data set, resulting in a statistically definable list of vegetation classes that can be reconciled with U.S. National Vegetation Classifi cation System-defi ned vegetation associations. The map unit delineation process consists of generating polygons using current digital colorinfrared aerial imagery, several ancillary data layers, and image processing techniques to define areas of similarity or dissimilarity across the INL Site. Products of these efforts then are reconciled by assigning vegetation classes to map units, resulting in a map that will be assessed for accuracy.

 

Summary: The fi nal classifi cation combined with the subsequent iterations of classification refinement resulted in 26 vegetation classes for the INL Site. Of the 26 vegetation classes identified, two are wooded or woodland types, seven are shrubland types, four are shrub herbaceous types, five are dwarf shrubland or dwarf-shrub herbaceous types, five are herbaceous types, and three are semi-natural herbaceous types. Semi-natural types are generally defined as being dominated by non-native species. Upon completion of the final classifi cation, the resulting plant community class list was used to identify polygons delineated through the mapping process. A dichotomous key to the vegetation classes was also developed.

 

The final vegetation map contains a total of 2,038 polygons, of which 1,964 (96.4 percent) represent vegetation communities. The remaining 74 polygons (3.6 percent) represent nonvegetation or agriculture classes we included in the map. The smallest mapped polygon is 0.0021 km2 (0.52 acres). The largest polygon mapped is 236.3 km2 (58,399.6 acres) located in the undisturbed interior portion of the INL Site. The accuracy assessment found highly accurate results for the overall map and also individual class accuracies for most vegetation classes. Although there has never been a quantitative evaluation of previous INL Site vegetation maps, the new map is the most detailed and likely the most accurate vegetation map ever produced for the INL Site.

 

The final project report includes a detailed description of statistical and image processing methods and results, field sampling protocols, the statistical community classification report, a dichotomous field key to the INL Site vegetation classes, vegetation class Fact Sheets that provide summary statistics and descriptions for each class identified during the plant community classification process, and a vegetation map book intended for field use or for individuals without GIS capabilities.

 

Vegetation Community Classification and Mapping of the INL Site (Final Report)