Identification of the shrub polygons from UAV imagery is described in detail in Herzog, Molly M., Andrew T. Hudak, David R. Weise, Ashley M. Bradley, Russell G. Tonkyn, Catherine A. Banach, Tanya L. Myers, et al. 2022. “Point Cloud Based Mapping of Understory Shrub Fuel Distribution, Estimation of Fuel Consumption and Relationship to Pyrolysis Gas Emissions on Experimental Prescribed Burns.” Fire 5 (4): 118. https://doi.org/10.3390/fire5040118.
Also available at URL https://www.fs.usda.gov/research/treesearch/64747 .