Research Of Soil Respiration Under Different Surface Conditions Of The North Shore Of Bosten Lake In Xinjiang

Soil Respiration is the process of producing and releasing carbon dioxide from the soil. Soil respiration is the important way of carbon cycling. The soil respiration promotes the exchange of CO2 between soil and atmosphere.Soil respiration is the largest flux in the carbon budget of terrestrial ecosystem, so it is a great factor to predict the carbon exchange between land and atmosphere.This study using LI-8100 automated soil CO2 flux measurement system, and in 2014 in April, July and October in North of Bosten Lake, Xinjiang, Shore exposed shoal, bare transition zone, Phragmites communis community, Tamarix chinensis community of soil respiration was measured and the effect of main environmental factors of soil respiration rate were observed.Summed up all kinds of soil respiration rate diurnal variation characteristics and different periods of soil respiration rate of transformation rules, analyzes the main environmental factors affecting soil respiration rate, to explore the mechanism of various factors on the impact of soil respiration rate. Research shows:1.Comparison of the diurnal variation of four plots of soil respiration rate.It is found that the diurnal variation in April,July,and October of bare beach to respectively for unimodal,bimodal and unimodal curve,the peak time were in 12:00-16:00;bare transition zone showed single peak type,the peak time was in 12:00-16:00.Phragmites communis community showed unimodal,bimodal and unimodal curve,the peak time was in 12:00-16:00;Tamarix community showed unimodal,bimodal and unimodal curve, the peak time was in 12:00-16:00.Thus it can be seen that four plots of peak time period is consistent with the bare shallows,Phragmites communis community, Tamarix group sunset changes of peak type the same.2.Different periods not similarly characteristics of soil respiration rate:exposed shoal soil respiration rate of mean value appeared in April,and others appeared in July, the order of magnitude for July > October > April.In to do comparative analysis on near surface temperature and 5cm depth of soil temperature and soil respiration rate, temperature index and the maximum value appeared in July,and respiratory rate maximum value appeared at the same time,three months minimum in the lowest temperature.3. The temperature and soil respiration rate were significantly correlated,but there were no obvious correlations of the individual months.Exposed shoal,bare transition zone,Phragmites communis community,Tamarix chinensis community in April,July,October the soil respiration rate and the near surface temperature and 5cm soil depth temperature showed significant correlation,and 10 cm depth soil temperature and 25 cm depth of soil temperature does not exist significant relationship.4. The relationship between soil respiration rate and relative humidity of air was analyzed, and the bare and bare transitional zone was found.April soil respiration rate and air relative humidity no correlation, bare beach to July soil respiration rate with air relative humidity changes present opposite trends, October soil respiration rate and air relative humidity no correlation; bare transition zone in July and October of soil respiration rate with air relative humidity changes showed significant negative correlation. The soil respiration rate of the reed community in April was significantly correlated with the relative humidity of the air, and the soil respiration rate in July and October was significantly negative correlated with the changes of the air relative humidity.There is no correlation between Tamarix chinensis community in April of soil respiration rate and relative air humidity, July, October soil respiration rate and the air relative humidity significantly negative correlation.5. The soil respiration rate and surface water content, 10 cm depth moisture content, 25 cm depth moisture content not have significant correlation, except bare transition zone of soil respiration rate and surface water had significant correlation, soil layers containing content and soil respiration rate showed a better quadratic equation.6. Take reed community in April, in July, October data as an example, carries on the correlation analysis to the soil breath speed and the wind speed, finally discovered each month of soil breath speed and the wind speed correlation coefficient respectively is 0.275,-0.164, 0.393, indicated soil breath speed and wind speed when April, in July, October the relevance is low.Cubic equation fitting discovery in April and in October soil breath speed and the wind speed relevance is weak,but July relevance is high is 0.85.