Higher temperature sensitivity of forest soil methane oxidation in colder climates

Area of Science:

• Environmental Science
• Microbiology
• Biogeochemistry

Background:

• Forest soils are significant sinks for atmospheric methane (CH4), influencing the global CH4 budget.
• The impact of rising temperatures on microbial methane oxidation in forest soils is not fully understood, leading to uncertainties in predicting future CH4 sinks.

Purpose of the Study:

• To investigate the spatial variation in the temperature response of forest soil microbial methane oxidation across eastern China.
• To identify the key factors driving these temperature sensitivities in forest soil methane oxidation.

Main Methods:

• Conducted field studies across 84 forest sites spanning a wide latitudinal gradient in eastern China.
• Measured microbial methane oxidation rates and analyzed environmental factors, including temperature, soil resources, and microbial community composition (methanotrophs).

Main Results:

• The temperature sensitivity of soil microbial methane oxidation significantly decreases as the mean annual temperature of the site increases.
• Observed a range of temperature sensitivity from 0.03 to 0.77 μg CH4 g-1 soil d-1 °C-1 across the studied sites.
• Identified soil resources and the abundance of type II methanotrophs as critical factors influencing this temperature response.

Conclusions:

• Warming negatively affects the temperature sensitivity of methane oxidation in forest soils.
• Accurate modeling of forest soil methane sinks under climate change requires integrating climate data, soil properties, and specific methanotroph groups.