Patterns in Plant-Microbiota Networks Along a Vegetation Diversity
Gradient in Alpine Grasslands
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.