Gradual CO(2) Increase More Strongly Boosts Nitrification and Ammonia Oxidizers in Paddy Soils Than Abrupt Increase.

Gradual CO2 increase more than doubles nitrification potential and significantly boosts ammonia-oxidizing bacteria and complete ammonia oxidizers in paddy soils.

• Why it matters: Understanding how different patterns of atmospheric CO2 rise affect soil nitrogen processes is crucial for predicting future ecosystem responses under climate change.
• What they did: The study used an automated system to compare three CO2 treatments—ambient, gradual (+40 ppm/year), and abrupt (+200 ppm)—and measured their effects on nitrification and ammonia oxidizer communities.
• The result: Gradual CO2 increase notably enhanced nitrification and the abundance of AOB and Comammox, highlighting its stronger influence on soil nitrogen cycling and community structure than abrupt increases.