1462 / 2024-09-27 14:55:16

Distribution and Variation of Greenhouse Gases along China's Coastal Wetlands

China coastal wetlands, Methane, Carbon dioxide, Nitrous oxide, Spatial distribution

As a major maritime country, China has a long coastline and abundant coastal resources. These areas are not only the concentration of human activities but also play an essential role in global climate change and the carbon cycle. Due to the uniqueness of the wetland environment, the characteristics of greenhouse gas emissions in these areas are significantly different from those of other ecosystems. In this study, a total of 36 monitoring stations were set up along the coastline of China from Fangchenggang to Dandong. Through field sampling, the spatial and temporal distribution characteristics of methane, carbon dioxide and nitrous oxide and their relationship with environmental factors were analyzed.

The results show that the distribution of methane, carbon dioxide and nitrous oxide shows obvious regional changes and specific dimensional changes. The content of methane showed a wave-like change with latitude, and a few sites ( such as Ningde, Wenzhou, Guangzhou, Zhanjiang ) showed significant high values, especially Ningde, which may be related to local estuary effects and human activities. In contrast, other high values appeared near mangrove areas and areas with abundant human activities. The distribution of carbon dioxide is relatively more uniform. The average value of carbon dioxide in the Bohai Sea is higher than that in other sea areas, which may be related to climatic conditions and lower temperatures. It is speculated that the carbon cycle process in this area is relatively slow, which limits the exchange of carbon dioxide. The concentration of nitrous oxide fluctuated between stations, and the concentration of Yingkou and Zhanjiang stations was significantly higher than that of other regions, which may be related to the influence factors of coastal agricultural runoff and mangroves. On the whole, the high-concentration areas are primarily concentrated in the vicinity of ecosystems such as estuaries, silt sediments, and mangroves, reflecting the interaction and common influence of regional natural factors ( such as climate and ecosystem types ) and human disturbances ( such as industrial and agricultural activities ).

Through this study, the distribution patterns of greenhouse gases in coastal wetlands in China were revealed, especially the differences in the effects of different regions and wetland types on methane, carbon dioxide, and nitrous oxide emissions. This provides critical data support for further understanding the sources and emission mechanisms of greenhouse gases in China's coastal wetlands and formulating relevant emission reduction policies.