黔中喀斯特石漠化地区土壤温室气体浓度的时空分布特征

2006~2007年对喀斯特石漠化地区土壤剖面中CO2、N2O和CH4的浓度分布进行观测.结果表明,土壤剖面中CO2、N2O和CH4浓度分别介于530.2~31512.6、0.27~0.67和0.1~3.5μL.L-1.总体上,自地表向下,CO2和N2O浓度逐渐增大,CH4浓度则为逐渐减小,但在阴冷潮湿的10、11月和1月,15cm以下土层中CO2和N2O浓度随着深度的增加逐渐减小,CH4浓度则明显增加.土壤温度、水分同时影响剖面中CO2、N2O和CH4的时空分布,但影响效应以及作用的土层深度有所不同.相关分析结果表明,土壤中CO2和N2O浓度的时空分布显著正相关(r为0.780~0.894,p0.05~0.01),相关关系受环境因子的影响;CO2和CH4的时空分布则呈显著负相关关系(r=330,p0.01);N2O和CH4的空间分布为互逆关系,但只在土壤水分较大月份达到显著水平(r为-0.829~-0.956,p0.05~0.01).

Temporal and Spatial Variations of Greenhouse Gases Concentrations in Soils in Karst Stone Desertification Areas in Central Part of Guizhou Province

Concentrations of CO_2, N_2O and CH_4 of soil profile; n Karst Stone Desertification Areas were measured monthly from June of 2006 to May of 2007. The results indicated that the concentrations of CO_2,N_2O and CH_4 varied from 530.2 to 31512.6, 0.27 to 0.67 and 0.1 to 3.5 μL·L~(-1) .On the whole, with the increase of soil depth, the concentrations of CO_2 and N_2O increased, while CH_4 decreased. However, in the cold and wet October, November and January, the concentrations of CO_2 and N_2O decreased with the depth below 15 cm. In contrast, CH_4 had the inverse trend. Soil temperature and moisture were the main factors which had impacts on the temporal and spatial variations of CO_2 , N_2O and CH_4 concentrations in soil profile, but the influence impacts were different. The correlation analysis showed that there was positive correlation between CO_2 and N_2O(r 0.780-0.894, p < 0.05-0.01), while correlation degree was controlled by environmental factors in different months.CH_4 concentrations in soil had significantly negative correlation with CO_2 concentrations( r = 330, p < 0.01) , but correlated with N_2O concentrations just in moisture months( r - 0.829- - 0.956, p < 0.05-0.01) .