The Temporal And Spatial Of CO₂, CH₄Emissions In Riverine Wetland And With Relations Of Soil Environment

On the surface of the earth, wetland is the most vital ecological service function of the ecological system, contains a lot of species and energy, maintains the normal operation of life activity, with water conservation and purification, flood storage effect of drought, but also has the adjusting air temperature, controlling ecological balance, and maintaining biodiversity and many kinds of important ecological functions.In July2011to October2011, this paper for a total of six times QiXingHe wetland nature reserve of four sample points’s wetland soil and gas sample collection. Among them, the sample point No.1and No.4wetland vegetation is lobular chapter, the No.2and No.3is reed marshes. Analysis the average emissions flux of CO2and CH4,with the same time and the same place of wetland soil samples, including the wetland soil organic carbon content, soil bulk density, soil moisture, soil temperature and pH, etc.Through laboratory experiments and calculation, it is known that the four sample points of CH4emissions average flux were0.472mg·m-2hr-1,23.340mg· m-2hr-1,0.120mg· m-2hr-1and0.019mg· m-2hr-1; CO2emissions average flux were736.156mg· m-2hr-1,948.741mg· m-2hr-1,1320.901mg·m-2hr-1and953.827mg-2hr-1.In the six times of the collecting samples, CO2in the four periods of sample point presented emissions, on a kind of spatial and temporal variation regularity. On the whole, with the temperature droping, the CO2gas emission is decreasing. In four sample points, CH4emissions were different from periods of flux, regular performance is not strong. In general, the sample point2CH4emissions flux was significantly higher than other three, the highest average was57.944mg·m-2hr-1. In comparison,the highest of No.1,3,4sample pointswere respectively0.307mg· m-2hr-1on September17,2,0.389mg· m-2hr-1on September,0.072mg· m-2hr-1on August17. The result shows that for every point of the overall significant difference CH4flux. No.2CH4emissions fluxes were significantly higher than others.In general, the change of the flux CO2and CH4relationship is not obvious. Sample points1and2, CH4and CO2flux on a positive correlation, but sample point3and4has not certain regularity.CH4and CO2emissions of soil were on a kind of positive correlation with soil humidity and flux of soil temperature. CH4and CO2emissions process of soil is a very complicated.Sometimes, the process of influential on emissions spatial variation regularity, and sometimes appears irregular phenomenon.A variety of reasons showed that the process of emissions was impacted by many factors, including soil moisture content critical value in soil and microbial activity and etc.