Estimation Of Soil Organic Carbon Storage In Palustrine Wetlands,China

Wetland is a complex ecosystem located in the"water-land"interaction zone.As an important place for the fixation and release of greenhouse gases,such as carbon dioxide（CO₂）and methane（CH₄）,its efficient carbon storage efficiency plays an important role in the soil-atmosphere carbon biogeochemical cycle.According to the survey,wetlands only account for 6%-8%of the world’s total land area,but carbon reserves account for about a third of the world’s organic carbon pool.At present,the environmental problem of global temperature rise is increasingly prominent.Wetland soil not only affects the global carbon balance,but also regulates global climate change.Therefore,the accurate estimation of wetland soil organic carbon storage plays an important role in the prediction of greenhouse effect.The lack of carbon accumulation data leads to the lack of reference values for the establishment of greenhouse gas emission reduction approaches and management strategies in China.Therefore,it is an urgent scientific and social problem in the field of wetland ecological environment protection,management,development and utilization to deeply study the carbon storage of marsh wetland and its response to global change.Therefore,on the basis of literature data,book data and measured data（a total of1383 sample points）,this study accurately estimated the soil organic carbon reserves of swamp wetlands in China by establishing a relationship model between the soil bulk density and organic carbon content by referring to the published relevant mathematical simulation equation.Simultaneously,the spatial-vertical differentiation law of soil organic carbon content in marshes and wetlands in China was discussed,and the main environmental factors affecting soil organic carbon content in marshes and wetlands were identified by using multivariate statistical methods such as redundancy analysis,path analysis and Structural equation models.Summarily,the main conclusions of this study are summarized as follows:（1）The total storage of organic carbon in palustrine wetlands was about 9.945 Pg,China.（2）The spatial distribution of soil organic carbon storage in China’s palustrine wetlands was uneven,mainly concentrated in the Qinghai-Tibet plateau,northeast China and northwest China,accounting for 99.11%of the total storage of soil organic carbon in China’s palustrine wetlands.The soil organic carbon density in per unit area soil was higher in the wetland area of northeast,southwest and Qinghai-Tibet plateau.（3）Except for the southeast and south wetland region,soil organic carbon content decreased with depth.（4）Within China’s terrestrial scale,the temperature and precipitation differences caused by latitude and elevation were the main environmental factors affecting the organic carbon content.For northeast and Qinghai-Tibet plateau wetland regions,pH and altitude were dominating environmental controls on SOC content,respectively.