Research On Greenhouse Gas Emission Fluxs And Their Influencing Factors In Oasis Soil Of Ebinur Lake

The front plain oasis of Ebinur Lake is an important part of the core area of the Silk Road Economic Belt.The ecological balance directly affects the economic sustainable development of the northern slope of the Tianshan Mountains in Xinjiang Province.However,there are few reports on the“source”and“sink”of greenhouse gases in the study area.The study used static box-gas chromatography to determine the daily variation of soil greenhouse gases(4 times per day)and months in the pre-mountain oasis,urban oasis,and Oasis-desert wetland transition in January,June and August of 2016 to 2017,while analyzing spatial changes.Combined with hydrothermal factors,soil physical and chemical factors and soil enzymes,the influencing factors of soil greenhouse gas emissions in the study area were discussed.The results show:(1)From the perspective of daily changes,except for the phenomenon of soil CO₂ carbon sink in the morning and evening of 9:00 in January and June,the rest of the time period is a carbon source phenomenon.Overall,the daily variation of soil CH₄emission flux is a phenomenon of carbon sink.The daily variation of soil N₂O emission flux is a phenomenon of carbon source except for the phenomenon of carbon sink in the morning and evening of 9:00.The daily variation of soil greenhouse gases in January was less than that in June and August.(2)From the change of the month,the mountain oasis area and the urban oasis area are the“source”of soil CO₂ emission in June and August,and the soil CO₂absorption“sink”in January;the Oasis-desert wetland transition is soil every month.The“source”of CO₂ emissions.The pre-mountain oasis area is the absorption“sink”of soil CH₄ in each month;the urban oasis area is the absorption“sink”of soil CH₄ in January and August,and the“source”of soil CH₄ emission in June;the Oasis-desert wetland transition is in 1 June is the“source”of soil CH₄ emissions,and August is the absorption“sink”of CH₄.Each month of the study area is the“source”of soil N₂O emissions.(3)From the perspective of spatial change,the soil greenhouse gas flux in January showed a strip-like distribution,and plaque-like distribution appearing in June and August.The urban oasis and the piedmont oasis are the“sinks”of CO₂ and CH₄ in January and June,and the“source”of soil CO₂ and N₂O in August.Desert wet areas are the“source”of soil greenhouse gasesevery month.(4)The semivariogram analysis shows that the spatial change of the oasis area in the foothills of the Aibi Lake in January is mainly due to structural factors.In June and August,the space between the mountain front oasis area and the oasis-desert wetland transition area is mainly influenced by structural factors,and the urban oasis area isaffected by both structural and random factors.Correlation and regression analysis found that the daily variation of soil greenhouse gas is mainly affected by soil temperature and moisture and air temperature and humidity.The monthly changes of soil greenhouse gases in different regions are mainly affected by soil enzymes and soil salinity,nutrient.(5)By comparing the CO₂,CH₄ and N₂O emission fluxes with other ecosystems at home and abroad,it is found that the CO₂,CH₄ and N₂O emission fluxes in the oasis of the Aibi Lake plain are relatively small,and the warming effect is low.