Various ecologicalfunctions of biocrusts are mostly determined by their bacterial and fungalabundance and community diversity, which has not yet been fully investigated.To provide more insights into this issue, we collected samples of mossbiocrusts, fixed sand, and mobile sand from a watershed with semi-aridclimate on the Loess Plateau of China. The relative abundances and communitydiversities of soil bacteria and fungi of the samples were determined usinghigh-throughput DNA sequencing. Finally, we analyzed the characteristics of bacterialand fungal community of the moss biocrusts and their relationships to thecontent of soil nutrients. Our results showed that the moss biocrusts had 1048bacterial OTUs (operational taxonomic units) and 58 fungal OTUs, and theirShannon diversity indexes were 5.56 and 1.65, respectively. The bacterialcommunity of the moss biocrusts was dominated by Acidobacteria (24.3%),Proteobacteria (23.8%), Chloroflexi (15.8%), and Actinobacteria (14.5%),and their fungal community was dominated by Ascomycota (68.0%) andBasidiomycota (23.8%). The moss biocrusts had far more bacterial OTUs (≥56.9%) but similar number of fungal OTUs ascompared with the uncrusted soil, and their Sorenson’s similarity coefficients of bacterial and fungal communitieswere less than 0.768 and 0.596, respectively. Moreover, the contents of soilnutrients (C, N, P) were significantly correlated with the OTU numbers ofbacteria and the relative abundances of bacteria and fungi. Our resultsindicated that moss biocrusts harbor a large number and high diversity ofbacteria and fungi, and these diversified bacteria and fungi play important rolesin ecosystem functioning through improving soil fertility.

Moss-dominated biocrusts increase soil microbial abundance and community diversi.pdf