The USGS Earth Resources Observation and Science (EROS) Center National Land Cover Database team in collaboration with the Bureau of Land Management (BLM) is producing the most comprehensive remote sensing based quantification of western United States shrublands to date. Nine individual products are being developed that represent the primary shrubland components: percent shrub, percent sagebrush, percent big sagebrush, percent herbaceous, percent annual herbaceous, percent litter, percent bare ground, shrub height, and sagebrush height. This approach relies on three major steps: creating training datasets using field measurements and high-resolution satellite imagery at selected sites, extrapolating these training datasets to the landscape level using Landsat 8, and validating the final products with independent field measurements. Product creation has been prioritized to focus on sagebrush ecosystems. Image nominal date 2013 products were developed in 2013 for southwestern Idaho, southeastern Oregon, northwestern Nevada, and northeastern California. Products from 2014 images were developed for the Mojave Desert, the Great Basin, western Utah, and southern Idaho in 2016. In addition, field sampling was completed for future products focused on the Sonoran Desert, Wyoming, and Montana. For sagebrush ecosystems, research has shown this approach enables more successful monitoring of gradual change and offers opportunities to develop historical 30-year trends of gradual habitat change from climate that can be projected into the future.
Status of USGS shrub and grass mapping by region. Dates listed in each region represent the nominal year of Landsat 8 imagery used for mapping the region.