Rising global temperatures reduce soil microbial diversity over the long term

Area of Science:

• Environmental Science
• Microbiology
• Climate Science

Background:

• Soil microbial diversity underpins ecosystem productivity and carbon sequestration.
• The impact of rising global temperatures on soil microbes and their carbon sequestration capacity is not fully understood.

Purpose of the Study:

• To investigate the effects of climate warming on soil microbial diversity and soil organic carbon (SOC) sequestration.
• To quantify the relationship between warming magnitude, duration, nitrogen availability, and microbial responses.

Main Methods:

• A global meta-analysis synthesizing data from 102 studies with 251 paired observations.
• Analysis of bacterial and fungal diversity using richness and Shannon index.
• Assessment of soil organic carbon (SOC) changes under warming conditions.

Main Results:

• Warming reduced bacterial and fungal diversity by 16.0% and 19.7%, respectively.
• Soil organic carbon (SOC) decreased by 18.1% on average due to warming.
• Negative impacts intensified with greater warming, longer experimental durations, and lower soil nitrogen.

Conclusions:

• Projected significant declines in microbial diversity and SOC sequestration under future warming scenarios.
• Warming-induced microbial diversity loss contributes to reduced SOC sequestration, creating a feedback loop.
• Urgent climate change mitigation is necessary to preserve soil health and carbon storage.