Figure 6. Principle components analysis (PCA) of transformed compositions of arthropod genera detected with repeated environmental DNA (eDNA) sampling in five watersheds.

Circles represent 2019 samples and squares represent 2020 samples. Filled green points represent PRWI1 samples and filled blue points represent CATO2 samples (see text for details). The same genus detected at both loci was treated as two independent variables. The proportion of the total variation explained by each axis is given in parentheses. A scree plot comparing the variation explained by each axis (eigenvalue percentage) relative to a null ‘broken stick’ model is shown in the inset, indicating that the plotted axes explain more variation than expected by chance.