Fungal phylogenies and plant functional traits structure root associated
fungal networks in a subtropical forest
Abstract
Rhizosphere fungi are essential for plant survival and ecosystem
functioning, but the processes structuring plant-fungal interactions
remain largely unknown. We constructed association networks between 43
plant species and two groups of root-associated fungi (mycorrhizal and
pathogenic) using sequence data. We revealed modularity within the
association networks using network analysis, and correlated this modular
structure with functional traits and phylogenetic history driving
plant-fungal interactions. We observed strong modularity in both
plant-mycorrhizal fungal and plant-pathogenic fungal association
networks. Plant functional traits and fungal phylogeny clustered within
modules. Host plants of mycorrhizal fungi differed significantly between
modules in terms of their leaf dry matter content, photosynthetic traits
and root tissue density. Host plants of pathogenic fungi differed
significantly between modules in terms of their dark respiration rate,
light compensation point and root morphology. Modularity within fungi
was a product of fungal phylogeny, whereas host plant modularity was a
product of functional traits (leaf morphology, photosynthetic rate and
root morphology). Our study illustrates the link between plant
functional traits and fungal assembly, and highlights the importance of
niche-based processes in shaping plant-fungus association networks. Our
results suggest that plant traits may be instrumental in managing the
composition of belowground fungal communities.