沙漠人工植被区土壤呼吸初探

Primary Discussion on Soil Respiration in Artificially Re-vegetated Desert Area

2003年9月底,在沙坡头铁路北面的1956年、1964年、1981年和1987年始植的人工植被区和流动沙丘的迎风坡,分别在阴天、晴天和雨后用CI301SR测定土壤呼吸速率,结果表明:土壤呼吸速率在各样地间、日期间和互作均达到极显著水平;尤其是雨后样地间的差异非常明显。1956年始植、1964年始植、1981年始植、1987年始植样地和流沙不同天气状况下的平均土壤呼吸速率分别为-0.1537μmol·s-1·m-2、-0.0995μmol·s-1·m-2、-0.0583μmol·s-1·m-2、-0.0754μmol·s-1·m-2和-0.0336μmol·s-1·m-2;阴天、晴天和雨后不同样地的平均土壤呼吸速率分别为-0.0342μmol·s-1·m-2、-0.0778μmol·s-1·m-2和-0.1403μmol·s-1·m-2。在沙漠人工植被区,影响土壤呼吸的主要因子是水分,其次是温度与植物群落类型和发育阶段。

The experiment based on CI-301SR aims to determine the soil respiration in windward of moving sand dune and in vegetation lands which were re-vegetated in 1956, 1964, 1981 and 1987. The observations were conducted on cloudy day (September18th), sunshine day (September 20th) and post-precipitation day (October 1st) in September 2003. The results showed that soil respirations among plots, among dates and interactions are very significantly variant (P<0.01), especially on post-precipitation day. The average soil respiration rates of plots which were re-vegetated in 1956, 1964, 1981 and 1987, and of bare desert are (-0.1537) mol\5s^(-1)\5m^(-2), (-0.0995) mol\5s^(-1)\5m^(-2), (-0.0583) mol\5s^(-1)\5m^(-2), (-0.0754) mol\5s^(-1)\5m^(-2) and (-0.0336) mol\5s^(-1)\5m^(-2), respectively. The average soil respiration rates on cloudy, sunshine and post-precipitation day are (-0.0342) mol\5s^(-1)\5m^(-2), (-0.0778) mol\5s^(-1)\5m^(-2) and (-0.1403) mol.s^(-1)\5m^(-2) in order. Soil water plays the dominant role on soil respiration in re-vegetated desert area, while temperature and the type and phrase of plant community are secondary.