Principal component analysis of read counts for amplicon sequence variants belonging to one of nine key plant families in unspiked (baseline) soil samples collected from Colorado (CO; circles), North Carolina (NC; squares) and Pennsylvania (PA; diamonds) determined by ITS2 DNA metabarcoding. The outline color of the shape denotes the kit (blue = PS [PowerSoil]; or orange = PSP [PowerSoil Pro]) and the color intensity denotes incubation temperature (light, 65 °C; dark, 90 °C). Axes represent the first and second principal components with percent variance explained in parentheses.