兴安落叶松生态系统近地表CH4浓度及其影响因子

摘要

采用DLT-100FMA快速甲烷分析仪对内蒙古大兴安岭北部兴安落叶松生态系统进行定位连续观测,分析兴安落叶松生态系统甲烷(CH4)的日变化、月变化规律及其影响因子.结果表明:1)生长季不同月份兴安落叶松CH4浓度的日变化随温度的升高而降低,最大值和最小值分别出现在1:00和13:00左右.2)CH4浓度的月变化呈现先减少后增大的规律,5月平均浓度为1.350 mg· m-3,6-9月分别为1.332、1.330、1.336 mg· m-3和1.349 mg· m-3,11月为1.384mg·m-3,7月最低为1.330mg ·m-3.3)CH4浓度随气温的升高而降低,相关关系为:y=7E-07x3+1E-05x2-0.001 8x+1.358 3(R2 =0.638 5,P＜0.01);CH4浓度随着空气湿度的增加呈现先降低后升高的变化趋势,湿度低于9285.71mg·m-3时,CH4浓度随湿度增大而降低;湿度高于9 285.71 mg· m-3时,CH4浓度随湿度增大而升高.%The DLT-100FMA rapid CH4 analyzer was used to conduct continuous observation in the Larix gmelinii ecosystem in northern Daxing'anling,Inner Mongolia.The diurnal and monthly variations of CH4 and its influencing factors in L.grnelinii ecosystem were analyzed.The results indicate that 1) the diurnal variation of the CH4 concentration decreased with the increase of temperature during the growing season.The maximum and minimum values were found at 1:00 and 13:00,respectively.2) The monthly CH4 concentration decreased at first and then increased.The average concentration in May was 1.350 mg · m-3;the average concentrations from June to September were 1.332,1.330,1.336 mg · m-3 and 1.349 mg ·m-3,respectively;the average concentration in November was 1.384 mg · m-3;the minimum concentration was 1.330 mg · m-3 in July.3) CH4 concentration decreased with the increase of temperature;the correlation equation was y=7E-07x3 + 1E-05x2-0.001 8x+ 1.358 3 (R2 =0.638 5,P＜0.01).With the increase of the air humidity,the CH4 concentration decreased at first and then increased.When the humidity was lower than 9 285.71 mg · m 3,the CH4 concentration decreased with the increase of humidity;when the humidity was higher than 9 285.71 mg · m-3,the CH4 concentration increased with the increase of humidity.