Exotic plants share putative fungal pathogens with natives
We found asymmetric sharing of pathogens between native and exotic
plants along the exotic gradient (Fig. 3). The relationship between
shared pathogens and exotic dominance in mixed communities (Fig. 3A)
deviated significantly from null expectations (Fig. 3B). Exotic plants
shared a greater proportion of pathogen OTUs than would be expected by
chance, compared with native plants, which shared fewer pathogen OTUs
than our null model predicted (Fig. 3) Plants shared 4% more pathogens
in home compared with away soils (χ2=6.37, p=0.01,
Table 1). The observed proportion of shared pathogens appeared to reach
a peak when the community contained approximately 60% exotic plants,
while it was lowest in communities with 25% exotic plants (when both
native and exotic plants were present; Fig. 3). Further, the efficiency
at which plants shared pathogens with other plants increased with the
proportion of exotic plants in the community, as indicated by increasing
values of closeness centrality with increasing exotic dominance
(χ2=15.68, p<0.001, Table 1, Fig. 1D).