Bacterial contributions of bio-crusts and litter crusts to nutrient cycling in the Mu Us Sandy Land

• Published in: Catena (Giessen) 2021-04, Vol.199, p.105090, Article 105090
• Main Authors: Liu, Xiaozhen, Liu, Yu, Zhang, Lei, Yin, Rui, Wu, Gao-Lin
• Format: Article
• Language: English
• Subjects: Bacterial communities; Bio-crusts; Litter crusts; Nutrient cycling; Sandy land restoration
• ISSN: 0341-8162; 1872-6887
• DOI: 10.1016/j.catena.2020.105090

[Display omitted] •Roles of litter crusts and biocrusts in sand land nutrient cycling were studied.•Litter crusts contained higher nutrients, enzyme activities, bacterial community.•These properties of litter crusts were more conductive to nutrient cycling.•Biocrusts and litter crusts promote sandy nutrient cycling through bacterial communities. Desertification has become an important issue for the sustainable development of human society at global scale and has led to the changes in soil properties and vegetation cover. Biocrusts and litter crusts play roles in improving the soil microhabitat of sandy ecosystems. Soil microbial communities mediate ecosystem functions in various ecosystems, e.g., soil biogeochemical processes. However, limited information is available about how the underlying processes of bio-crusts/litter crusts restoration are driven by soil bacterial communities in sandy land. Here, we investigated the changes in soil bacteria from three groups (sandy land, bio-crusts, and litter crusts) and three soil layers (0–2 cm, 2–5 cm, 5–10 cm) with nine replicates each collected in July 2019 utilized high-throughput pyrosequencing of the V4-V5 rRNA gene region. Most soil nutrients (SOM, AP, AK, and TN) and enzyme activities (BG and DHA) had differences among the three groups and three soil layers. OTU richness and diversity of bacteria were positively correlated with most soil variables. The constructed co-occurrence networks between soil variables and bacterial communities, and within bacterial communities showed that bacterial taxa had closer relationships with all soil variables in crusts than sandy land and varied among the three sand groups (sandy land, bio-crusts, and litter crusts). The result showed that the composition of bacterial community was regulated mainly by soil variables and crust types. Compared with sandy land, more predictors in nutrient cycling were found in crust types. They played major roles in nutrient cycling in desert ecosystem restoration on the basis of random forest modeling. Our findings indicate some bacterial taxa may played the predominant roles in connecting with soil variables and other bacterial taxa across crusts types, and litter crusts and bio-crusts drive the nutrient cycling by mediating the restoration of bacterial taxa in sandy ecosystems.