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Early Estimates of Exotic Annual Grass (EAG) in the Sagebrush Biome, USA, 2022 (ver 4.0, June 2022)

June 17, 2022

These datasets provide early estimates of 2022 fractional cover for exotic annual grass (EAG) species and a native perennial grass predicted on May 6th using satellite observation data available no later than April 29th. Four fractional cover maps comprise this release, along with the 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); 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.