The Soil Respiration And Total Belowground Carbon Allocation Of Betula Costata Secondary Forest And Mixed Broadleaved Korean Pine Forest In Xiaoxing’an Mountains,China

Controlling mechanisms of soil respiration and total belowground carbon allocation,the two most improtant carbon fluxes of forest ecosysterns,are of much significance in understanding the forest carbon source/sink,reginal forest budget and forest carbon management. We chose mixed broadleaved Korean pine forest and Betula costata secondary forest in Xiaoxing’an Mountains.The results indicated that soil temperation at 10 cm significantly influenced the seasonal dynamics of soil respiration and its components, it could explain 65% and 64% of the viriation of soil respiration in two forest types,with maximum values in summer and minimum values in the early and late growing season. It was found that the soil respiration、soil hetetrophic respiration and soil autotrophic respiration increase exponentially with soil temperature in the mixed broadleaved Korean pine forest and Betula costata secondary forest, Q10 value of soil respiration for two forest types was 2.28 and 2.38 respectively; Q10 value of soil hetetrophic respiration was 2.28 and 2.38 respectively; Q10 value of soil autotrophic respiration was 2.28 and 2.38 respectively.The mean soil respiration rate of mixed broadleaved Korean pine forest and Betula costata secondary forest was 4.26μmol·m-2·s-1 and 4.36μmol·m-2·s-1 respectively; the mean soil hetetrophic respiration rate was 3.26μmol·m-2·s-1 and 3.05μmol·m-2·s-1 respectively; the mean soil autotrophic respiration rate was 1.07μmol·m-2·s-1 and 1.43μmol·m-2·s-1 respectively.Contribution of soil hetetrophic respiration rate to soil respiration rate was 74% and 69% in two forest types, respectively.The annual flux of soil respiration in Mixed broadleaved Korean pine forest and Betula costata secondary forest was 8.36t·hm-2 and 8.52t·hm-2 respectively;the annual flux of soil hetetrophic respiration was 5.62t·hm-2 and 4.97t·hm-2 respectively;the annual flux of soil autotrophic respiration was 2.73t·hm-2 and 3.55t·hm-2 respectively. The total belowground carbon allocation in Mixed broadleaved Korean pine forest and Betula costata secondary forest was 6.53 t·hm-2·a-1 and 6.63 t·hm-2·a-1 respectively.