Soil organic carbon stabilization is influenced by microbial diversity and temperature

Area of Science:

• Soil Science
• Microbiology
• Environmental Science

Background:

• Soil organic carbon (SOC) stabilization is key for soil health and climate change mitigation.
• Temperature and soil microbial diversity are critical factors influencing SOC decomposition and stabilization.

Purpose of the Study:

• To investigate the effects of temperature and microbial diversity on stabilized SOC formation.
• To analyze the impact on mineral-associated organic carbon (MAOC) and water-stable aggregates.

Main Methods:

• A 75-day soil incubation experiment was conducted.
• Measurements included water-stable aggregates, microbial respiration, and SOC fractions.
• Different levels of microbial diversity (low, medium, high) and temperatures (ambient, elevated) were applied.

Main Results:

• Low microbial diversity led to significantly lower total and particulate organic carbon (POC).
• Elevated temperature reduced macroaggregate-occluded MAOC across all diversity levels.
• Medium microbial diversity soils showed highest POC and MAOC at ambient temperature, but this was disrupted by elevated temperature.

Conclusions:

• Microbial diversity is crucial for SOC stabilization, with medium diversity being optimal under ambient conditions.
• Elevated temperatures negatively impact SOC stabilization by affecting aggregate formation and POC/MAOC dynamics.
• Understanding these temperature-sensitive microbial-driven C dynamics is vital for predicting soil carbon fate under climate change.