摘要
采用动态密闭气室法(IRGA)和碱液吸收法(AA)对科尔沁沙地不同生境(固定、半固定和流动沙丘)土壤呼吸的日动态、季节动态及其影响因子进行了测定分析,并对两种方法进行了比较。结果表明:(1)从固定到半固定沙丘、半固定到流动沙丘,随着植物群落盖度及土壤有机质含量的降低,土壤呼吸速率呈现递减的趋势。整个测定期用IRGA法和AA法测定的平均土壤呼吸速率,固定沙丘分别为2.348和0.878μmolCO_2·m^(-2)·s^(-1),半固定沙丘分别为1.666和0.812μmolCO_2·m^(-2)·s^(-1),流动沙丘分别为1.061和0.573μmolCO_2·m^(-2)·s^(-1)。(2)各生境土壤呼吸速率的昼夜变化与气温和土壤温度的变化趋势一致,与近地表空气湿度的变化趋势相反。(3)各生境土壤呼吸速率的季节变化与温度不完全同步,但其对温度的依赖程度显著高于土壤水分。(4)AA法测定的结果明显低于IRGA法,平均为IRGA法的48%;两种方法具有很好的相关性(R^2 =0.649 5,p<0.001)。
The daily and seasonal variations of soil respiration were mensurated by dynamic closed-chamber infra red gas analysis （IRGA） method and alkali absorption （AA） method in different habitats （fixed, semi-fixed and mobile dunes） in Horqin Sandy Land. The effecting factors of soil respiration and the differences between two methods were also analyzed in this paper. The major results were as follows ： （ 1 ） soil respiration rate was weakened from fixed to semi-fixed dune and semi-fixed to mobile dune, decreasing with plant communities＇ coverage and soil organic matter content. The mean soil respiration rates during the study period determined by IRGA and AA method are 2.348 and 0. 878 μmolCO2·m^-2·s^-1 in fixed dune,respectively,1. 666 and 0. 812 μmolCO2·m^-2·s^-1 in semi-fixed dune,1. 061 and 0.573 μmolCO2·m^-2·s^-1 in mobile dune; （2） the daily variations of soil respiration presented same trend with that of air and soil temperature, and reverse of surface air relative humidity; （3） the seasonal variations of soil respiration were similar to those of temperature, but were not completely consistent with each other. The effect of temperature on soil respiration was more significant than that of soil water content ; （4） the average soil respiration rate in three habitats measured by AA method was 48% of that by IRGA method, and the correlation between them was highly significant （R^2 = 0. 6495 ,p 〈 0. 001 ）.
出处
《干旱区地理》
CSCD
北大核心
2008年第5期680-686,共7页
Arid Land Geography
基金
中国科学院西部之光西部博士项目(0828881002)
国家自然科学基金(40601008
40471004)
中科院野外台站基金(1731690200015)资助
关键词
土壤呼吸
动态密闭气室法
碱液吸收法
科尔沁沙地
soil respiration
closed-chamber IRGA method
alkali absorption method
Horqin Sandy Land
