Red alder trees distribution in the United States Pacific Northwest for 2002 summarized for NHDPlus v2 catchments

This spatial data set was created by the U.S. Geological Survey (USGS) to represent the basal area of red alder trees within each incremental watershed delineated in the NHDPlus v2 dataset in the Pacific Northwest region of the United States (Hydro Region 17; Major River Basin 7 (MRB7)) in 2001.

本空间数据集由美国地质调查局（U.S. Geological Survey，USGS）编制，旨在表征美国太平洋西北地区（水文区域17；主要流域7（MRB7））2001年NHDPlus v2数据集中各增量划定汇水区内的红桤木胸高断面积。