FIG 4.

Variation partitioning by principal coordinates of neighbor matrices (PCNM)-based analysis for the phylogenetic structure of bacterial communities into an environmental component (top left), a linear trend (top right), and a broad-scale spatial pattern (bottom). A forward selection procedure was used to select the best PCNM variables (no spatial correlation) important to the bacterial community structure. Sediment environmental variables included dissolved inorganic nitrogen (DIN) and sea depth, which constrained 5.8% and 5.4% of the variation, respectively.