Table 2. Topological statistics for networks of bacteria at each depth (Figure 1), and for a network of OTUs at all depths (Figure 2).
| 5 m | DCM | 150 m | 500 m | 890 m | AllvAll | |
|---|---|---|---|---|---|---|
| Eligible nodes | 110 | 102 | 113 | 106 | 106 | 537 |
| Nodes (N) | 73 | 77 | 83 | 82 | 57 | 463 |
| Edges (E) | 112 | 112 | 141 | 124 | 154 | 2301 |
| Cl | 0.34 | 0.33 | 0.23 | 0.21 | 0.34 | 0.17 |
| L | 2.37 | 2.02 | 2.33 | 2.37 | 2.14 | 3.46 |
| ClR | 0.04 | 0.04 | 0.04 | 0.04 | 0.09 | 0.02 |
| LR | 3.73 | 3.92 | 3.61 | 3.88 | 2.54 | 2.91 |
| Cl/ClR | 8.33 | 8.78 | 5.75 | 6.02 | 3.59 | 8.10 |
| L/LR | 0.63 | 0.51 | 0.65 | 0.61 | 0.84 | 1.19 |
| Intra-depth density | 4.3% | 3.8% | 4.1% | 3.7% | 9.6% | 2.2% |
| Inter-depth density | 1.6% | 2.1% | 1.7% | 1.8% | 2.8% | NA |
| Density ratio | 2.71 | 1.82 | 2.47 | 2.12 | 3.43 | NA |
Abbreviation: DCM, deep chlorophyll maximum. This table complements Supplementary Figure S1 which visually depicts the network described here. These networks include only nodes for bacteria that are present at >0.01% abundance greater than 25 times (eligible nodes) and edges that have a possibly time-lagged, global, absolute Spearman ρ value of greater than 0.5 or less than −0.5. Nodes are the bacterial OTUs that are connected by at least one edge to another node. Edges are the number of correlations between bacterial OTUs. Density is the number of edges (E) divided by the number of possible edges {N*(N-1)/2} such that {Density=E/(N*(N-1)/2)}. Cl is the clustering coefficient for the network. L is the mean path length for the network. ClR and LR are the median clustering coefficients and path lengths of 1000 equivalently sized (same number of nodes and edges) randomly distributed networks. Cl/ClR is the ratio of the clustering coefficient to the median random network's clustering coefficient. Permutation tests suggest that clustering and path length coefficients are statistically significantly different than those for random (P<0.001). It is apparent that 890 m has higher density than the other depths. Clustering coefficient relative to random networks (Cl/ClR) is highest in the DCM. Like the DCM, 890 m has a high level of absolute clustering, which reflects as several highly connected groups in Supplementary Figure S1E.