Fig. 1

A Alpha diversity of CAWS samples by sample type. The distribution of Shannon diversity indices for each sample type is consolidated for all seven sampling years (2013–2019). This box and whisker plots demonstrate the quartile range and outliers for each distribution. Statistical groupings are designated by the letters above the boxplots. Significance was assessed using paired Wilcoxon tests with Benjamini–Hochberg multiple testing corrections. B Beta diversity analysis of CAWS samples by sample type. PCoA plot based on the unweighted UniFrac distance matrix showing clustering patterns of different sample types. C Aggregated seasonal plots of beta distances as a function of month, for each sample type. The dots connected by solid black lines represent the mean beta distance between each sample community and a fixed baseline community of the same sample type and site. The blue density bands describe the distribution of beta distances to a baseline community, for each particular month. The dashed line signifies the mean beta distance value of all samples relative to its baseline community for a given sample type, and represents the null expectations given that seasonality plays no role in the community. As no collections were conducted in December, January, and February (axis labeled in red), the values of these months were interpolated using spline regression