Effects of mixed biocrusts on soil nutrients and bacterial community structure：A case study from Hilly Loess Plateau, China

Abstract

In this paper, 16S rRNA sequencing analysis was carried out on the mixed crust and the surface layer of bare soil and soil under the crust in this area, and combined with the soil physical and chemical factors, the influence of the mixed crust on the bacterial community structure in the loess hilly area was explained. The results show that mixed crusts can significantly increase the conventional nutrient content of the soil in terms of fast acting phosphorus, total nitrogen and organic matter. In addition, the mixed crust layer develops its own specific bacterial community structure, with Rubrobacteria and Cyanobacteriia specifically enriched in the mixed crust layer. Redundancy analysis (RDA) showed that these particularly enriched species could be involved in the process of photosynthesis and nitrogen fixation, thereby increasing the levels of organic matter and organic nitrogen in the soil. The results of the study provide an important theoretical basis for the microbiology of ecological restoration in the hilly and gully areas of the Loess Plateau.