Figure legends
Fig. 1. Bipartite incidence networks of Frankia OTUs withinAlnus host individuals (a) and soils (b). Samples and detectedFrankia OTUs from each sample are represented x- and y-axes,
respectively. (b) gray area represents OTUs from riparian soils and
white area represents OTUs from host rhizosphere soils. Colors indicates
each river area (blue: BT; red: DR; green: SE; yellow: UT).
Fig. 2. (a) Non-metric multidimensional scaling of Frankiacommunity among nodules and rhizosphere of the A. hirsuta , and
riparian soils. Circles indicated Frankia communities in hosts’
root–nodules. Triangles indicated the communities in rhizosphere soils.
Squares indicated the communities in riparian soils. (b) FrankiaOTU richness in host’s root nodules and null model by random sampling.
The asterisk represents P-value of difference of OTU richness between in
nodules and null model by GLM (***: P < 0.001).
Fig. 3. (a) Correlation between genetic distance of A. hirsutaand symbiosis filtering difference. (b) Proportions of unique and shared
deviance explained on symbiosis filtering difference. GD: Nei’s genetic
distance of hosts (black); OTHER: measured predictors including spatial
distance among hosts, soil pH, amount of inorganic nitrogen in soils,
and community dissimilarity of Frankia in rhizosphere soils based
on Jaccard index (gray); BOTH: both predictors (white).