小兴安岭原始阔叶红松林和枫桦次生林土壤有机碳库比较研究

土壤有机碳含量是全球生态系统碳储量变化的重要指标之一，本研究以空间替代时间序列的方法，分别选取了小兴安岭地区原始阔叶红松林和枫桦次生林并测定土壤有机碳库、土壤全氮含量、土壤微生物量碳及土壤相关理化性质，结果表明，土壤有机碳含量(SOC)、土壤全氮含量(TN)、土壤微生物量碳(MBC)、土壤含水率等指标随着土壤层的深度增加而逐渐减少最后趋于稳定，而土壤容重随着土壤层的加深而增大。在原始林中0~10和10~20cm层的SOC、TN含量差异不显著，而次生林则差异显著。原始阔叶红松林和枫桦次生林的土壤有机碳密度(SOCD)分别为21.46和21.3 kg·m^-2，差异不显著。原始林和次生林的平均有机碳含量分别为35.79，28.6 g·kg^-1，土壤全氮含量分别为2.86，1.83 g·kg^-1，枫桦次生林MBC与SOC的线性相关性高于原始林。结果表明原始林土壤肥力高于次生林，在今后次生林的管理中应适当混栽针叶树种，原始林中应适当间伐使地下碳储量增加。

Comparison of Soil Organic Carbon Stock of Betula costata Secondary Forest and Mixed Broadleaved Korean Pine Original Forest in Xiaoxing’an Mountains.

Soil organic carbon content plays an important role in the global ecosystem carbon stock revolution. By space replacing time series method, we chose two types of forests of mixed broadleaved Korean pine original forest and Betula costata secondary forest to measure the soil organic carbon(SOC) stock, soil nitrogen(TN) content, microbial biomass carbon(MBC) and other soil chemistry and physical properties. The SOC, TN, MBC contents are gradually decreased with the increase of the depth of soil layer, and finally to a stable value. On the contrary, the soil bulk density increases with the increase of depth of the soil layer. There is no significant difference in 0-10 cm soil layer’s SOC,TN content and 10-20 cm soil layer at original forest, but there are significant relations in e two soil layers at secondary forest. The soil organic carbon densities(SOCD) of original forest and secondary forest are 21.46 and 21.3 kg·m^-2, respectively. There is no significant difference between two forest types. The mean soil organic carbon contents of original forest and secondary forest are 35.79 and 28.6 g·kg^-1, respectively. Soil total nitrogen contents of original forest and secondary forest are 2.86 and 1.83 g·kg^-1, respectively. The liner correlation of microbial biomass carbon and soil organic carbon in secondary forest is higher than original forest. The soil fertility of original forest is more than secondary forest. It is better to plant mixed coniferous with pine species in the secondary forest, and have appropriate thinning in original forest to balance the underground carbon system.