Early Estimates of Exotic Annual Grass (EAG) in the Sagebrush Biome, USA, 2022, May 18th, 2022

These datasets provide early estimates of 2022 fractional cover for exotic annual grass (EAG) species and one native perennial grass species on a bi-weekly basis from May to early July. The EAG estimates are developed within one week of the latest satellite observation used for that version. Each bi-weekly release contains four fractional cover maps along with their corresponding confidence maps for: 1) a group of 16 species of EAGs, 2) cheatgrass (Bromus tectorum); 3) medusahead (Taeniatherum caput-medusae); and 4) 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); HLS-based Normalized Difference Water Index (NDWI); other relevant environmental, vegetation, remotely sensed, and geophysical drivers; and artificial intelligence/machine learning techniques. A total of 19,415 AIM plots from years 2016 – 2021 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) that developed all the fractional cover maps. The geographic coverage includes arid and semi-arid rangelands in the western U.S at or below 2350-m elevation. Note: Maps of May 6th, 2022 were developed using satellite observation data no later than April 29. Maps of May 18th, 2022 were developed using satellite observation data no later than May 13.