Forest conversion changed the structure and functional process of
tropical forest soil microbiome
Abstract
The effects of forest conversion from natural forest to agricultural
system on soil microbial composition still need further study.
Especially, impact on soil function after forest conversion is not yet
known. In this study, by using metagenomic sequencing as well as 16S and
ITS sequencing technology, we evaluated the soil microbial composition,
diversity and functions based on a large number of soil samples of
tropical rainforest and rubber plantation across the whole island of
Hainan, south China. The results showed that (1) forest conversion
changed microbial composition from bacterial groups of Proteobacteria to
Chloroflexi, and fungal groups from Basidiomycota to Ascomycota. (2) The
bacterial alpha diversity, beta diversity as well as the total diversity
did not decrease after forest conversion. However, beta diversity of
fungal community reduced resulting a net loss of total OTU richness. (3)
There was no difference in soil functional compositions and diversity
between rubber plantations and rainforest, however, the relative gene
abundance of most COG functions, KEGG functions, CAZy functions as well
as Antibiotic gene were significantly different between rubber
plantation and tropical rainforest. (4) Soil pH and environmental
heterogeneity were the main driver for microbial taxonomic composition
and gene functional composition. Land use did not result in changes of
functional gene composition, but the relative abundance of functional
gene. The changed relative abundance gene would alter the ecosystem
processes. In conclusion, our results confirmed that land use changes
alter the soil microbial community structure and can have profound
effects on ecosystem functions and processes.