Abstract: Wetland ecosystem plays an important role in global carbon cycle. Its unique soil, hydrology, and vegetation make the wetland able to constantly accumulate carbon in the hypoxic environment, and also, release large amount of greenhouse gases CH₄ and CO₂. Wetland carbon emission has become a hotspot in the study of global climate change. The differences in the soil status, hydrological condition, and vegetation type in wetland result in a strong spatiotemporal variability of CH₄ and CO₂ emission from wetland. It’s observed that the  CH₄ and CO₂ emission is positively correlated with soil temperature, and affected by water level to a certain extent. Within a certain range, soil anaerobic condition leads to the increase of CH₄ emission and the decrease of CO₂ emission. Vegetation affects all aspects of the greenhouse gases production, oxidation, and emission, and the affecting degree varies with plant species.

Key words: Plutella xylostella, Pesticide, Life table