Stability of soil microbial structure and activity depends on microbial diversity

Area of Science:

• Soil microbiology
• Ecology
• Environmental science

Background:

• Microbial communities are crucial for soil functions, but their diversity's impact on soil stability is debated.
• The ecological insurance hypothesis suggests higher biodiversity enhances ecosystem stability.

Purpose of the Study:

• To investigate the relationship between soil microbial diversity and community stability under mercury pollution and heat stress.
• To test the ecological insurance hypothesis in soil microbial ecosystems.

Main Methods:

• Manipulated microbial diversity using the dilution extinction approach.
• Assessed structural and functional stability via genetic structure and soil respiration.
• Utilized 454 sequencing of ribosomal genes to confirm diversity gradients.

Main Results:

• A clear diversity gradient was established across treatments.
• Species-rich communities showed enhanced structural stability regardless of stress.
• Functional stability improved with diversity after heat stress but not mercury pollution.
• The effect of diversity on functional stability was modulated by soil resources.

Conclusions:

• The ecological insurance effect on soil microbial communities is stress-dependent.
• Microbial diversity is critical for functional stability, especially with higher soil resources.
• Global change factors may exacerbate the negative impacts of microbial diversity loss on soil functions.