中文摘要：

以长白山针叶林和阔叶林2种林型的2个土壤层次（A层与O层）为供试土样,分别于30℃恒温（恒高）、10℃恒温（恒低）、1030℃循环变温条件下的变温低温（变低）和变温高温（变高）进行4个月室内培养,测定不同时期土壤呼吸速率（RS）,并藉此计算恒、变温模式Q10值。研究表明,不同处理RS一致呈现变低〈恒低,变高〉恒高（P〈0.001）,且变温模式Q10（均值2.23）明显高于恒温处理Q10（均值1.51）（P〈0.001）。不同林型或土层RS对温度变化敏感程度不同,呈现针叶林变幅略大于阔叶林,A层比O层变化更为强烈。上述差异可能与恒、变温培养模式下土壤微生物群落结构和底物可用性变异有关。因此,在测算土壤呼吸Q10时应考虑温度变化所带来的影响。

英文摘要：

Soil samples were collected from 2 horizons（horizon O and A） separately in broad-leafed deciduous forest and coniferous forest. A four-month microcosm study was conducted under continuously varying vs. constant temperature regimes： constant low at 10 ℃, constant high at 30 ℃, and under a regularly-varying temperature regime：stage 1（varying low）, 10 ℃ for 6 h; stage 2, increasing smoothly from 10 to 30 ℃ for 6 h; stage 3, 30 ℃ for 6 h（varying high）; stage 4, decreasing smoothly from 30 to 10 ℃ for 6 h. During the incubation course, soil respiration rates（RS） and their Q10 values were measured separately under constant and varying temperature regimes. The results showed that RSin different treatments generally ranked as varying low 〈 constant low, and varying high 〉 constant high（P 〈 0.001）. In addition, Q10 values were significantly greater under varying temperature regimes（averaging at2.23） than constant ones（averaging at 1.51）（P 〈 0.001）. Forest types and soil horizons varied in temperature sensitivity and generally ordered as broad-leafed deciduous forest 〈 coniferous forest and horizon A 〉 horizon O,respectively. The distinct variation of soil microorganism community and substrate availability might cause the differences of RSand their Q10 values between varying and constant temperature regimes. Therefore, the estimation on Q10 values of soil respiration should consider the effects of temperature variation.