Abstract
Understanding how the network
structure of plant and microbiota interactions differ along ecological
gradients is of great interest. We studied network patterns at 60 sites
across the Tibetan Plateau, representing a gradient in both
precipitation and plant species richness.
The number of fungal OTUs that were
uniquely connected to each plant species in the plant-fungi network was
most strongly positively related to plant species richness. By contrast,
the number of unique bacterial OTUs linked to each plant species
decreased with increasing plant species richness. The number of fungal
OTUs specifically linked to each plant species was positively related to
plant species richness, and to productivity. We suggest that
in a more extreme high-stress
environment that decreases plant species richness, plants and fungi have
fewer excess resources to invest in specific relationships, showing up
as lower associated microbiome richness, with bacteria may partially
replacing this role in high stress/low productivity environments.