The structure of natural microbial enemy-victim networks

Ecological Processes

Table 1 Structural metrics for the five networks studied

Network	Connectance	Nestedness	Generality	Vulnerability	Q _bip	m	Q _R
1	0.80	82.03	0.80 ± 0.25	0.80 ± 0.12	0.05	2	0.58
2	0.85	82.31	0.85 ± 0.11	0.85 ± 0.15	0.06	2	0.54
3	0.59	77.28	0.58 ± 0.28	0.58 ± 0.16	0.15	2	0.64
4	0.81	79.76	0.81 ± 0.29	0.81 ± 0.12	–	–	–
5	0.75	80.56	0.75 ± 0.30	0.75 ± 0.13	0.08	2	0.48

Values for species-level metrics are mean ± standard deviation. Nestednesses (as measured by NODF) were higher than expected when tested against four null models (see Additional file 1). Generality (infection) and vulnerability (1 - resistance) are given as the proportions of the total number of bacteria exploited and associated exploiting phages respectively. Q_bip and m are respectively Barber’s bipartite modularity score and the number of identified modules using LP-BRIM (see the ‘Methods’ section). Q_R is ‘realised’ modularity (Poisot 2013), i.e. the proportion of links occurring between species sharing a module (values close to 0.5 indicate that half of the links are established by isolates from different modules).