Characteristics Of Wetland Soil Greenhouse Gas Emission In Regions With Different Degrees Of Permafrost Degradation

Global warming leads to the degradation of permafrost in the xingan mountains,which causes changes in soil habitat and physical and chemical properties,and then affects various microbial processes to cause differences in the emission fluxes of various greenhouse gases.CH₄,CO₂and N₂O are three important greenhouse gases,which have a significant impact on global climate change.In the frozen CH₄,CO₂and N₂O emissions flux differences are the result of comprehensive effect of various environmental factors are complicated,in different parts of the hinggan mountains forest wetland soil,for example,in different types of regions,by studying the flux difference,thus,wetland soil greenhouse gas emissions of global warming temperatures cause hinggan mountains region of permafrost degradation in greenhouse gas emissions characteristics of wetland research,help to clarify permafrost degradation mechanism of response to global warming,to assess the impact of climate change on regional evaluation plays an important role.This research takes yichun xiao xing yong qing forest farm in seasonal frozen?D1?,the greater hinggan mountains JGD south urn river island permafrost regions?D2?and the big xingan mountain mohe North Pole village continuous permafrost regions?D3?forest wetland soil as the research object,using static field in-situ experiment box-gas chromatography to determination of the greenhouse gas emission flux,determination of soil physical and chemical properties and environmental factors at the same time,the analysis under the condition of different types of permafrost greenhouse gases and the relationship between soil physical and chemical properties and environmental factors.The experimental results show that:1.During the growing season,the wetland soil of the three types of permafrost areas is the source of CO₂and N₂O,while D1 and D3 are the source of CH₄,but D2 is the source of CH₄sink.The greenhouse gas emission flux of soil presents an increasing trend with the aggravation of permafrost degradation.2.In terms of the main influence factors of CH₄emission fluxes,the CH₄emission fluxes of D1 are positively correlated with soil moisture content and fine root biomass of 0?10cm and 10?20cm,while the CH₄emission fluxes of D₂are positively correlated with soil temperature of 5cm,10cm,15cm,20cm and 25cm,but negatively correlated with soil moisture content of 10?20cm.The CH₄emission flux of D3 was positively correlated with the content of 10?20cm DOC,the soil moisture content of 0?10cm,10?20cm and the soil temperature of 5cm,10cm and 15cm.3.In terms of main factors that influence the CO₂emission flux,D1 CO₂emission flux and soil temperature of 5 cm and litter biomass showed positive correlations,D2 of CO₂emission flux and soil temperature of 0 cm,0?10 cmdoc content and root biomass has significant positive correlation,D3 CO₂emission flux and soil temperature and 0 cm 0?10cmdoc content present a positive correlation.4.In terms of the main influencing factors of N₂O emission flux,the N₂O emission flux of D1 has a significant positive correlation with the soil bulk density of 10?20cm,while the N₂O emission flux of D2 has a positive correlation with the soil bulk density of 0?10cm,10?20cm,0?10cm TC,0?10cm TN,10?20cm DOC,and 0?10cm,10?20cm TDN.The N₂O emission flux of D3 was positively correlated with soil bulk density of 0?10cm,0?10cm,10?20cm TC,0?10cm,10?20cm TN and soil temperature of 25cm.This study conclude that the greenhouse gas emission flux in different types of permafrost regions have different characteristics,the fine root biomass and soil moisture content is the main influence factors of CH₄emission flux D1,D2 of CH₄emission flux is mainly affected by water content and temperature,D3 CH₄emission flux is mainly affected by soil moisture content,soil,the influence of the lower temperature and the content of DOC.The CO₂emission flux of D1 is mainly affected by the soil temperature of 5cm and litter biomass,the CO₂emission flux of D2 is mainly affected by the soil temperature of 0cm,the DOC content of 0-10cm and the root biomass,and the CO₂emission flux of D3 is mainly affected by the soil temperature of 0cm and the content of 0-10cmdoc.Main factors influencing the D1 N₂O emission flux is lower bulk density,soil N₂O emission flux and 10?20 cm soil bulk density has a significant positive correlation,similarly N₂O emission flux of D2 and D3 also has significant positive correlation with the soil bulk density,D3 N₂O emissions and deep soil temperature has significant correlation,soil carbon and nitrogen content is mainly to D2 and D3 N₂O emissions have influence,is one of the main factors promoting the N₂O emissions.