Research Progress on the Mechanisms of Wetland Greenhouse Gas Emissions and Their Environmental Driving Factors

Wetland ecosystems play a vital role in the global carbon and nitrogen cycles as well as climate regulation.They serve not only as important carbon sinks in terrestrial ecosystems but also as one of the major natural sources of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).The processes of greenhouse gas emissions from wetlands are co-regulated by multiple environmental factors and biological processes, exhibiting complex mechanisms and significant spatial and temporal heterogeneity, which introduce considerable uncertainty in the context of global change.Systematically reviewing the mechanisms of wetland greenhouse gas emissions and their key driving factors is of great importance for scientifically assessing the comprehensive climate effects of wetland ecosystems and optimizing wetland conservation and restoration management.Based on a synthesis of relevant domestic and international research, this paper systematically reviews the mechanisms of production, transformation, and emission of CO2, CH4, and N2O in wetlands, with a focus on the regulatory roles of key environmental factors such as soil organic carbon, water conditions, temperature, pH, redox status, and microbial processes.Additionally, this paper discusses the major challenges and uncertainties in the study of wetland greenhouse gas emissions, and suggests that future research should strengthen integrated multi-greenhouse gas observations, quantitative characterization of microbial process rates, and mechanistic analysis of interactions among environmental factors, in order to enhance the capacity for comprehensive assessment of the net climate effects of wetlands.This review provides a theoretical reference for the science-based management and functional enhancement of wetland ecosystems in the context of climate change.