Early Estimates of Exotic Annual Grass (EAG) in the Sagebrush Biome, USA, 2025 (ver. 1.0, April 2025)

These datasets provide early estimates of 2025 fractional cover for exotic annual grass (EAG) species and one native perennial grass species on a weekly basis from mid April to late June. Typically, the EAG estimates are publicly released within 7-13 days of the latest satellite observation used for that version. Each weekly release contains five fractional cover maps along with their corresponding confidence maps for: 1) a group of 16 species of EAGs, 2) Cheatgrass (Bromus tectorum); 3) Field brome (Bromus arvensis); 4) Medusahead (Taeniatherum caput-medusae); and 5) Sandberg bluegrass (Poa secunda). These datasets were generated leveraging field observations from Bureau of Land Management (BLM) Assessment, Inventory, and Monitoring (AIM) data plots; Harmonized Landsat and Sentinel-2 (HLS) based Normalized Difference Vegetation Index (NDVI); other relevant environmental, vegetation, remotely sensed, and geophysical drivers; and artificial intelligence/machine learning techniques. A total of 40,154 AIM plots from years 2016–2024 were used to train an ensemble of five-fold regression-tree models using a cross-validation approach (each observation was used as test data once and as training data four times) that developed all the fractional cover maps. The geographic coverage includes arid and semi-arid rangelands in the western U.S classified as shrubs or grassland/herbaceous by the 2023 Land Cover product from Annual National Land Cover Database (NLCD) CONUS Collection 1.0 at or below 2350-m elevation.
Note:
Maps of April 18th, 2025, were developed using satellite observation data no later than April 12.
Releases:
First Release: April 18, 2025 (ver. 1.0)