Bacterial association networks
The connectance and betweenness centrality of habitat patch networks varied with habitat patch effects, but modularity did not. Network connectance was significantly lower in REGUA patches than in networks constructed for sites outside of REGUA (Figure 5B; Wilcoxon Rank Sum test, p-value=0.012). Betweenness centrality was higher in networks for patch F4, F2, and F1 (i.e., smallest patches), corresponding with their band-like network structure (Figure 4), and centrality was significantly different between networks from large and small patches (Figure 5c; Kruskal-Wallis chi-squared statistic = 300.23, p-value < 2.2 x 10-16). Raw and Z-score modularity of habitat patch networks did not significantly differ between REGUA and non-REGUA sites, but tended to be lower in patches outside REGUA (Figure S8). Z-score modularity using the measured networks for standardization did not control for network size and shape, and mimicked the pattern exhibited by raw modularity. Modularity measures standardized by null distributions did not support patterns of decreasing modularity with decreasing patch area (Figure S8).