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采用动态密闭气室法测定分析了科尔沁沙地典型玉米(Zea mays)农田垄上和垄间土壤呼吸速率的差异及自养和异养呼吸特征,并估算了生态系统碳平衡。结果表明:(1)垄上和垄间土壤呼吸速率存在极显著差异(p<0.001),且存在线性关系(p<0.05);季节水平上垄上土壤呼吸可解释垄间土壤呼吸98.4%的变异。(2)季节水平上土壤总呼吸(RS)、异养呼吸(RH)和自养呼吸(RA)的温度敏感性指数Q10大小顺序为:RA(4.35)>RS(3.10)>RH(2.08)。(3)RS和RH之间存在显著差异,RA与RS和RH之间不存在显著差异;RA占RS比例的季节变化范围为28.1%~71.1%,生长季RH和RA占RS的比例均值分别为44.4%和55.6%。(4)科尔沁沙地典型农田生态系统在生长季为碳汇,可净固存大气CO2-C的量为659.1g·m-2。
Dynamic confined gas chamber method was used to analyze the difference of soil respiration rate and autotrophic and heterotrophic respiration characteristics of ridge and ridge in farmland of typical corn (Zea mays) in Horqin sandy land, and to estimate the ecosystem carbon balance. The results showed that: (1) there was a significant difference (p <0.001) in soil respiration rate between the ridge and the ridge, and there was a linear relationship (p <0.05); on the seasonal level, the soil respiration in the ridge explained 98.4% variation. (2) The order of temperature sensitivity index Q10 of total soil respiration (RS), heterotrophic respiration (RH) and autotrophic respiration (RA) at the seasonal level was: RA 4.35 RS> 3.10 RH 2.08 . (3) there is a significant difference between RS and RH, there is no significant difference between RA and RS and RH; the seasonal variation range of RA to RS ratio ranges from 28.1% to 71.1%, the average ratio of RH and RA to RS in growing season 44.4% and 55.6%. (4) The typical farmland ecosystem in Horqin sandy land is carbon sink during the growing season, and the net CO2-C content of the net solidified land is 659.1 g · m-2.