Key microorganisms mediate soil carbon-climate feedbacks in forest ecosystems.

Area of Science:

• Microbiology
• Ecology
• Climate Science

Background:

• Soil microorganisms play a critical role in regulating terrestrial carbon (C) cycling and its feedback to climate change.
• Predicting future C cycling is challenging due to the high diversity of soil microbes and their varied responses to environmental factors.

Purpose of the Study:

• To investigate the relationship between soil microbial community composition and the microbial community-level thermal response (MCTR).
• To understand how MCTR influences ecosystem-scale soil C-climate feedbacks across various forest biomes.

Main Methods:

• Analysis of bacterial community composition from 169 forest sites spanning tropical to boreal gradients.
• Correlation of microbial community data with environmental factors (temperature, pH) to determine MCTR drivers.

Main Results:

• Dominant bacterial phyla across sites were Actinobacteria and Acidobacteria.
• MCTR in warm, acidic soils was primarily driven by bacteria.
• MCTR in cold, alkaline soils was predominantly associated with fungi.

Conclusions:

• Soil microbial community composition is a strong indicator of MCTR.
• Specific microbial groups (bacteria and fungi) play distinct roles in regulating soil C-climate feedbacks in different environments.
• Findings highlight the importance of microbial diversity in climate change predictions.