| Soil respiration is an important way of CO2 emissions from ecosystems to the atmospheric. It is the main flux of carbon cycle between ecosystems and atmosphere. As an important component of boreal forest ecosystems, high intensity forest fires often occur in XiaoXing’an Mountain, and cause uncertainty in the global carbon balance. Whereas, there is on in-depth studies about short-term soil respiration after fire disturbance in this area. This study was conducted in burned areas of L. gmelinii and B. platyphylla forests in Xiao Xing’an Mountain, the unburned nearby areas served as the control. The rate of soil respiration was examined in burned and control areas. We also explored the differences of short-term soil respiration between the burned and control areas. What we tried to explain were as follows:(1) to quantify soil respiration rate from June to December in L. gmelinii and B. platyphylla forests; (2) to explore the differences of short-term Rs and Rh between the burned and control areas, and study the effects of fire disturbances on short-term soil respiration; (3) analyzing the relationship between Rs/Rh and soil temperature/soil moisture content, and also Rs/Rh and soil organic carbon, and building the models. The purpose of this study is to find out the change of fire disturbance on soil respiration. This study would provide a scientific basic data for researches on effects of fire disturbance on short-term soil respiration, and serves as an excellent reference for soil respiration on the response of fire disturbance in more depth study.The results were as follows:1) The control sample of B. platyphylla forests:Rs ranged from 0.881 to 9.683μmol·m-2·s-1, Rh ranged from 0.854 to 6.967μmol·m-2·s-1; The burned sample of B. platyphylla forests: Rs ranged from 0.973 to 6.976μmol·m-2·s-1, Rh ranged from 0.722 to 5.943μmol·m-2·s-1; The control sample of L. gmelinii forests:Rs ranged from 0.796 to 7.221μmol·m-2·s-1, Rh ranged from 0.681 to 5.508μmol·m-2·s-1; The burned sample of L. gmelinii forests:Rs ranged from 0.678 to 7.889μmol·m-2·s-1, Rh ranged from 0.684 to 5.923μmol·m-2·s-1.2) The ranges of variation of soil temperature and Q10 of the two forest types were as follows:The control sample of B. platyphylla forests:soil temperature of total soil respiration for 0.9～17.8℃, Q10 for 4.48, soil temperature of heterotrophic respiration for 0.9～18.2 ℃, Qio for 3.67; The burned sample of B. platyphylla forests:soil temperature of total soil respiration for 0.7～18.7℃, Q10 for 3.53, soil temperature of heterotrophic respiration for 0.4 ～17.7 ℃, Q10 for 4.39; The control sample of L. gmelinii forests:soil temperature of total soil respiration for 0～18.0 ℃, Q10 for 3.74, soil temperature of heterotrophic respiration for 0.1～ 17.3 ℃, Q10 for 4.09; The burned sample of L. gmelinii forests:soil temperature of total soil respiration for 0.4～16.7 ℃, Qio for 3.94, soil temperature of heterotrophic respiration for 0.2 ～16.8 ℃,Q10 for 4.18.3) In this study, the prediction model of soil respiration taking into account soil temperature and humidity and their interaction effect, explained 82.9% and 93.6% of Rs and Rh changes of the control sample of B. platyphylla forests, explained 88.8% and 91.6% of Rs and Rh changes of the burned sample of B. platyphylla forests, explained 88.6% and 76.8% of Rs and Rh changes of the control sample of L. gmelinii forests, explained 72.9% and 84.1% of Rs and Rh changes of the burned sample of L. gmelinii forests. Also we take soil temperature and humidity and their interaction effect and soil organic carbon into the prediction model of soil respiration. The models explained 83.9% and 88.9% of Rs and Rh changes of the control sample of B. platyphylla forests, explained 90.3% and 93.3% of Rs and Rh changes of the burned sample of B. platyphylla forests, explained 72.9% and 86.2% of Rs and Rh changes of the control sample of L. gmelinii forests, explained 90.1% and 83.8% of Rs and Rh changes of the burned sample of L. gmelinii forests. |
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