Ethiopia has undergone significant land use change during the past
centuries, particularly deforestation. These changes have resulted in
the loss of topsoil as well as the associated soil ecosystem functions.
Grazing exclusion and planting of eucalyptus are measures used to
recover degraded lands and reduce deforestation, respectively. Using a
gradient of the intensity of land use from natural forest to croplands,
we investigated whether these measures also result in restoration of the
soil microbial community. We identified the soil bacterial and fungal
communities using paired-end amplicon sequencing. A total of 12,765
fungal and 12,325 bacterial OTUs were detected in the five land use
types, and only ca. 2% and 17% were shared among the land uses,
respectively. Total fungal and bacterial OTU richness was not
significantly affected by land use change, but the conversion of forest
to cropland resulted in the loss of approximately 40% and 11% of the
total native fungal and bacterial OTUs, respectively. Soil pH, C, N, and
aggregate stability were key factors corresponding to the overall
bacterial and fungal community compositions. We also showed
relationships between the microbial functional group and enzyme
activities. The exclusion of grazing led to an enrichment of soil
microbial communities that overlapped with the communities of the
natural forest. Our results suggest that remnant native forests act as
refugia for microbial communities and that restoration of microbial
communities and concomitant recovery of ecosystem function via
deintensification of land use is possible. Keywords: ectomycorrhiza,
ericoid mycorrhiza, exclosure, microbial diversity, soil enzymes
Land use change alters functional gene diversity, composition and abundance in Amazon forest soil microbial communities