Higher temperature sensitivity of forest soil methane oxidation in colder climates

Abstract

Forest soils, serving as an important sink for atmospheric methane (CH₄), modulate the global CH₄ budget. However, the direction and magnitude of the forest soil CH₄ sink under warming remain uncertain, partly because the temperature response of microbial CH₄ oxidation varies substantially across geographical scales. Here, we reveal the spatial variation in the response of forest soil microbial CH₄ oxidation to warming, along with the driving factors, across 84 sites spanning a broad latitudinal gradient in eastern China. Our results show that the temperature sensitivity of soil microbial CH₄ oxidation significantly declines with increasing site mean annual temperature, with a range of 0.03 to 0.77 μg CH₄ g^–1 soil d^–1 °C^–1. Moreover, soil resources and type II methanotrophs play crucial roles in shaping the temperature sensitivity of soil microbial CH₄ oxidation. Our findings highlight the importance of incorporating climate, soil resources, and methanotroph groups into biogeochemical models to more realistically predict forest soil CH₄ sink under warming.