Data from: Soil organic matter quantity and quality shape microbial community compositions of subtropical broadleaved forests

As two major forest types in the subtropics, broadleaved evergreen and
broadleaved deciduous forests have long interested ecologists. However,
little is known about their belowground ecosystems despite their
ecological importance in driving biogeochemical cycling. Here, we used
Illumina MiSeq sequencing targeting 16S rRNA gene and a microarray named
GeoChip targeting functional genes to analyse microbial communities in
broadleaved evergreen and deciduous forest soils of Shennongjia Mountain
of Central China, a region known as ‘The Oriental Botanic Garden’ for its
extraordinarily rich biodiversity. We observed higher plant diversity and
relatively richer nutrients in the broadleaved evergreen forest than the
deciduous forest. In odds to our expectation that plant communities shaped
soil microbial communities, we found that soil organic matter quantity and
quality, but not plant community parameters, were the best predictors of
microbial communities. Actinobacteria, a copiotrophic phylum, was more
abundant in the broadleaved evergreen forest, while Verrucomicrobia, an
oligotrophic phylum, was more abundant in the broadleaved deciduous
forest. The density of the correlation network of microbial OTUs was
higher in the broadleaved deciduous forest but its modularity was smaller,
reflecting lower resistance to environment changes. In addition, keystone
OTUs of the broadleaved deciduous forest were mainly oligotrophic.
Microbial functional genes associated with recalcitrant carbon degradation
were also more abundant in the broadleaved deciduous forests, resulting in
low accumulation of organic matters. Collectively, these findings revealed
the important role of soil organic matter in shaping microbial taxonomic
and functional traits.