These layers represent estimates of imputed tree density calculated as part of the ecological assessment of upland hardwood systems. The GCPO Integrated Science Agenda targets tree densities of around 40 trees/acre for upland hardwood woodland systems and around 80 trees/acre for upland hardwood forest systems. These metrics should be correlates with target endpoints of basal area and canopy cover, though not entirely synonymous. We again used plot-level FIA data imputed across the GCPO LCC to assess tree density. However, it was challenging to identify and map the very limited acreage amounts meeting exactly this target in upland hardwood woodlands and forest. We therefore assessed the mean tree density within each forest type, and acres meeting the target endpoint, ±10 trees/acre from the target endpoint. We first extracted the imputed FIA live tree density data, provided courtesy of the U.S. Forest Service Remote Sensing Applications Center, through the upland hardwood woodland and forest masks. We then reclassified each to extract woodlands with exactly 40 trees/ac as well as within a range of 30-50 trees/acre, and forests with exactly 80 trees/ac, as well as within a range of 70-90 trees/acre. We did explore the potential of using standard deviations from the mean to density conditions, but the wide range of density resulted in standard deviation metrics that were too broad for use in this dataset. We summarized the data spatially as a binary reclassification of the target range (0,1), by summing acres within each GCPO subgeography, and by calculating the proportional area of a HUC12 watershed falling into the target tree density range for woodlands and forest.
