Figure 1.

(A). Sites across the Pacific Northwest (USA), where ectomycorrhizal fungal (EMF) communities associated with Populus trichocarpa were sampled. (B) EMF colonized root length was inversely correlated with mean annual precipitation (MAP; P = .04; R² = 0.21). (C) Significant taxonomic and functional coupling for EMF communities, as measured using counts of Pfam annotated genes (Bray–Curtis distances). Taxonomic dissimilarity is measured using fungal amplicon sequence variants (ASV). For (B and C), Lines represent linear splines with 95% confidence intervals.