Soil pH determines the alpha diversity but not beta diversity
of soil fungal community along altitude in a typical Tibetan
forest ecosystem
Abstract
Purpose Despite their symbiotic relationship with trees and
the vital role as decomposer in forest, soil fungi received limited
attention regarding their changes with altitude in forest
ecosystems. This study aimed to determine the diversity patterns
of soil fungi along an altitudinal gradient on Mt. Shegyla,
a typical forest ecosystem on the Tibetan Plateau.
Materials and methods High-throughput barcoded pyrosequencing
and quantitative PCR approaches were employed
to measure the community composition, diversity, and abundance
patterns of soil fungal 18S ribosomal RNA (rRNA)
gene in 20 samples collected along the altitudinal gradient of
Mt. Shegyla.
Results and discussion Abundant taxa in the fungal community
were Agaricomycetes and Leotiomyceta on Mt. Shegyla.
Fungal abundance decreased significantly with increasing altitude.
Beta diversity of the fungal community, as measured
using weighted UniFrac distance, was significantly related to
altitude. Significant correlation was observed between altitude
and alpha diversity including richness and phylodiversity, but
not with evenness. Network analysis revealed that
Ceramothyrium and Clavulina were two important hubs in
the community, and an uncultured fungal taxon that previously
detected in glacier forefront dominated this network.
Distance-based linear model identified soil pH as the dominant
driver which significantly related with fungal alpha diversity
including richness, phylodiversity, and evenness.
However, fungal abundance and the first component of PCoA
on weighted UniFrac matrix (beta diversity) did not change
significantly with pH.
Conclusions These results provided strong evidence that soil
pH was the dominant driver for structuring altitudinal alpha
diversity pattern but not beta diversity pattern or community
abundance of soil fungi in this typical forest on the Tibetan
Plateau.