生态环境学报
生態環境學報
생태배경학보
ECOLOGY AND ENVIRONMENT
2009年
5期
1938-1943
,共6页
土壤呼吸%温度%水分%Q_(10)%羊草草原
土壤呼吸%溫度%水分%Q_(10)%羊草草原
토양호흡%온도%수분%Q_(10)%양초초원
soil respiration%temperature%moisture%Q_(10)%Leymus chinensis steppe
采用静态暗箱-气相色谱法对内蒙古锡林河流域羊草(Leymus chinensis)草原土壤呼吸进行测定,研究了温度和水分条件对土壤呼吸温度敏感性系数Q_(10)值的影响.结果表明羊草草原土壤呼吸与5cm地温具有很好的指数关系(r~2=0.338～0.858,P<0.001～0.08),Q_(10)介于1.15～2.25之间,均值为1.72.Q_(10)值与5 cm地温呈负相关关系(r~2=0.407),而与0～10 cm土壤水分含量呈显著的二次函数关系(r~2=0.872,P<0.05).在较低含水量时Q_(10)值随着水分含量的上升而增大,当土壤水分含量较高时转而减小.以往大多数研究认为Q_(10)值与土壤水分含量呈正相关关系,这可能是土壤水分跨度不足造成的,极端的水分条件对Q_(10)值具有重要影响.
採用靜態暗箱-氣相色譜法對內矇古錫林河流域羊草(Leymus chinensis)草原土壤呼吸進行測定,研究瞭溫度和水分條件對土壤呼吸溫度敏感性繫數Q_(10)值的影響.結果錶明羊草草原土壤呼吸與5cm地溫具有很好的指數關繫(r~2=0.338～0.858,P<0.001～0.08),Q_(10)介于1.15～2.25之間,均值為1.72.Q_(10)值與5 cm地溫呈負相關關繫(r~2=0.407),而與0～10 cm土壤水分含量呈顯著的二次函數關繫(r~2=0.872,P<0.05).在較低含水量時Q_(10)值隨著水分含量的上升而增大,噹土壤水分含量較高時轉而減小.以往大多數研究認為Q_(10)值與土壤水分含量呈正相關關繫,這可能是土壤水分跨度不足造成的,極耑的水分條件對Q_(10)值具有重要影響.
채용정태암상-기상색보법대내몽고석림하류역양초(Leymus chinensis)초원토양호흡진행측정,연구료온도화수분조건대토양호흡온도민감성계수Q_(10)치적영향.결과표명양초초원토양호흡여5cm지온구유흔호적지수관계(r~2=0.338～0.858,P<0.001～0.08),Q_(10)개우1.15～2.25지간,균치위1.72.Q_(10)치여5 cm지온정부상관관계(r~2=0.407),이여0～10 cm토양수분함량정현저적이차함수관계(r~2=0.872,P<0.05).재교저함수량시Q_(10)치수착수분함량적상승이증대,당토양수분함량교고시전이감소.이왕대다수연구인위Q_(10)치여토양수분함량정정상관관계,저가능시토양수분과도불족조성적,겁단적수분조건대Q_(10)치구유중요영향.
Soil respiration rates were measured with static opaque chamber-chromatographic technique in an experimental plot of IMGERS (Inner Mongolia Grassland Ecosystem Research Station). The effect of soil temperature and moisture on temperature sensi-tivity of soil respiration was studied. Soil respiration increased exponentially with soil temperature at 5 cm depth (r~2=0.338～0.858, P<0.001～0.08). The temperature sensitivity of soil respiration (Q_<10>) has been widely used in estimating soil respiration rate. A small change in Q_<10> could cause a significant variation in the modeled soil respiration flux. Therefore, accurately quantifying Q_<10> and its variability is crucial for estimating ecosystem carbon budget. Our research showed that the Q_<10> values ranged from 1.15 to 2,25 with an average of 1.72. The Q_<10> value was negatively correlated with soil temperature at 5 cm depth, however, it related to soil moisture (0～10 cm) with a significant quadratic function (r~2=0.872, P<0.05). In contrast to other reports that Q_<10> value was positively corre-lated with soil moisture, our result showed that this positive correlation existed only when soil moisture was relatively low and Q_<10> decreased when soil moisture nearly reached the field moisture capacity. Extreme soil water conditions will significantly affect the estimate of Q_<10>.
