Effects of global change on methane uptake in forest soils and its mechanisms: A revie

Abstract

Elevated atmospheric CO2 concentration, altered precipitation regime, increased nitrogen deposition, and land cover change have not only changed the physical and chemical properties of forest soils, but also affected plant growth and microbial activity, with concequences on soil carbon and nitrogen cycles, including soil CH4 uptake. In this study, we summarized the important role of soil CH4 uptake in forests under global change scenarios. The differences of responses as well as the underlying mechanisms of soil CH4 uptake in forests to global change were reviewed. Elevated atmospheric CO2 concentration inhibits soil CH4 uptake. Reduced precipitation tends to promote soil CH4 uptake. Increased nitrogen input inhibits soil CH4 uptake in nitrogen-rich forests, but promotes or has no effects on soil CH4 uptake in nitrogen-poor forests. Conversion of forests to grassland, farmland, or plantations would reduce soil CH4 uptake, while afforestation increases soil CH4 uptake. The future research should explore the long-term and multiple effects of global changes on forest soil CH4 uptake. In addition, molecular biology methods should be developed to explore the microbial mechanism of soil CH4 uptake.