Soil bacterial diversity mediated by microscale aqueous-phase processes across biomes

Area of Science:

• Soil Science
• Microbiology
• Ecology

Background:

• Soil bacterial diversity is crucial for ecosystem functioning and varies significantly across different biomes.
• Understanding the factors driving soil bacterial abundance and diversity is essential for predicting ecological responses to environmental changes.

Purpose of the Study:

• To develop a mechanistic modeling framework to predict soil bacterial diversity and abundance.
• To identify key factors influencing soil bacterial communities across spatial scales.
• To delineate global hotspots of soil bacterial diversity.

Main Methods:

• Incorporated soil type, carbon inputs (from net primary productivity), and climate into a modeling framework.
• Investigated the influence of soil aqueous-phase content and connectivity on bacterial diversity.
• Validated the heuristic model against an individual-based mechanistic model and observed global trends.

Main Results:

• Soil aqueous-phase content and connectivity strongly influence bacterial diversity across soil types and rainfall patterns.
• Intermediate water content, creating disconnected habitats, supports the highest bacterial diversity.
• Carbon inputs constrain bacterial abundance independently of diversity.

Conclusions:

• The developed model accurately captures global trends in soil bacterial diversity.
• Hotspots of soil bacterial diversity are primarily located in climatic transition zones vulnerable to change.
• Findings highlight the sensitivity of soil bacterial communities to climate and land use changes.