Microbial network properties and functional gene diversity drive soil multifunctionality during biocrust succession

Area of Science:

• Ecology
• Microbiology
• Environmental Science

Background:

• Biological soil crusts (biocrusts) are vital for desert ecosystem functions, including soil stabilization and nutrient cycling.
• Understanding the microbial mechanisms behind biocrust-mediated soil multifunctionality (SMF) is crucial for arid land management.

Purpose of the Study:

• To investigate the microbial mechanisms driving SMF in different biocrust types (algal, lichen, moss) in the Mu Us Desert.
• To compare the influence of microbial community structure, network complexity, and functional gene diversity on SMF.

Main Methods:

• Systematic sampling of biocrusts and subcrust soils.
• Metagenomic sequencing to analyze microbial communities and functional genes.
• Co-occurrence network analysis to assess microbial interactions.
• Quantification of SMF using an integrative index based on C, N, and P cycling parameters.

Main Results:

• Moss-dominated biocrusts exhibited the highest SMF, followed by lichen and algal crusts.
• Microbial network density, not taxonomic diversity, significantly correlated with SMF.
• Diversity of carbon degradation and nitrogen cycling genes showed a positive correlation with SMF.

Conclusions:

• Biocrusts enhance SMF through direct and indirect effects on nitrogen cycling functional gene diversity and microbial network complexity.
• Functional gene diversity is a key driver of biocrust-mediated ecological functions in desert ecosystems.
• Findings provide a framework for sustainable land management and ecological restoration in drylands.