Fig. 1

Peat viral community and population (vOTU) abundance patterns with depth in the SPRUCE experimental plots. A Principal coordinates analysis (PCoA) of viral community composition in 82 samples (total soil metagenomes) from peat bog soil from the Marcell Experimental Forest in northern Minnesota (USA) collected from the SPRUCE experimental plots and chambers (temperature treatments ranging from ambient to + 9 °C above ambient), based on Bray-Curtis dissimilarities derived from the table of vOTU abundances (read mapping to vOTUs, n = 2699). Each point is one sample (n = 82). B Mean relative abundances (Z transformed) of vOTUs significantly differentially abundant by depth (adjusted p < 0.05, Likelihood ratio test). Groups were identified through hierarchical clustering and are colored according to the depths in panel A. C Percentage of vOTUs classified as “aquatic-like” in each of the groups identified in panel B (Groups 1–3) and in the whole dataset of 2699 vOTUs (Total). SPRUCE vOTUs were considered “aquatic-like” if they shared a genus-level viral cluster (VC) with at least one vOTU from a marine or freshwater habitat in the PIGEON database. Note that the y-axis maximum is 10%. *** Denotes a significantly larger proportion of aquatic-like vOTUs in that group, relative to the proportion of aquatic-like vOTUs in the full SPRUCE dataset (Total) (p < 0.05, Hypergeometric test)