Elevated carbon dioxide accelerates the spatial turnover of soil microbial communities

Area of Science:

• Environmental microbiology
• Ecology
• Geochemistry

Background:

• Elevated CO2 (eCO2) impacts soil microbial communities locally, affecting diversity, composition, and function.
• However, the effects of eCO2 on the regional and global geographic distribution of microorganisms remain largely unknown.

Purpose of the Study:

• To investigate the impact of eCO2 on the spatial turnover (β-diversity) of soil microbial communities across multiple geographic sites.
• To determine the influence of geographic distance and soil properties on microbial β-diversity under ambient and elevated CO2 conditions.

Main Methods:

• Analysis of 110 soil microbial communities from six Free Air CO2 Enrichment (FACE) experimental sites.
• Utilized a high-throughput functional gene array to assess microbial β-diversity.
• Statistical analysis to correlate β-diversity with geographic distance and soil properties.

Main Results:

• Soil microbial β-diversity was significantly correlated with geographic distance under both ambient CO2 (aCO2) and eCO2.
• The rate of β-diversity decline with distance was significantly faster under eCO2 (-0.0250) compared to aCO2 (-0.0231).
• Both geographic distance and soil properties were significant contributors to microbial β-diversity.

Conclusions:

• Elevated CO2 accelerates the spatial turnover rate of soil microbial communities at a regional scale.
• Findings suggest that eCO2 influences microbial community assembly mechanisms across broader geographic areas.
• These insights are critical for predicting microbial community responses in the context of increasing global CO2 concentrations.