Key bacterial, fungal, and protist taxa regulate nutrient availability
during vegetation restoration under different climate conditions in
karst soil
Abstract
To determine the mechanisms underlying the response of microbial
interactions to vegetation restoration under different climate
conditions, we examined the changes occurring at two temperature levels
in soil bacterial, fungal, and protist microbiomes under a reference
cropland and a plantation forest and a shrubland. Bacterial and protist
diversity levels in the high-temperature region of Guangxi (20.9 °C)
were higher in cropland than in shrubland or plantation forest. By
contrast, fungal richness was lower under cropland than shrubland. The
bacterial phyla Cyanobacteria, Gemmatimonadetes, and Nitrospirae, the
fungal taxa Ascomycota and Mucoromycota, and the protist groups
Ciliophora, Lobosa, and Ochrophyta had lower abundance under vegetation
restoration than cropland. There were no significant differences between
shrubland and plantation forest in terms of bacterial, fungal, or
protist diversity or community composition. A co-occurrence network
revealed higher numbers of correlated links among bacterial, fungal, and
protist taxa in the low-temperature region of Guizhou (14.6 °C) than
Guangxi. Stronger interactions were observed among microbial taxa under
cropland than under vegetation restoration. Protist groups Cercozoa and
Lobosa showed the highest numbers of links with bacterial phyla
Acidobacteria and Proteobacteria and with fungal phylum Ascomycota.
Hence, a strong food web existed among these microbiomes.
Proteobacteria, Acidobacteria, Ascomycota, and Cercozoa were correlated
with soil nutrient levels. Therefore, these dominant taxa determined
nutrient availability. The predation of bacteria and fungi by protists
was more intense at low temperature than high temperature. Key
bacterial, fungal, and protist groups, their co-occurrence networks, and
environmental temperature influence soil nutrient accumulation during
vegetation restoration.