兴安落叶松林碳平衡及管理活动影响研究

摘要

在利用大兴安岭地区根河落叶松(Larix gmelini)林生态系统定位研究站的实际观测资料验证CENTURY模型的基础上,探讨了林业经营管理方式对兴安落叶松林碳循环的影响,指出:1)目前兴安落叶松林是一个碳汇,每年净吸收碳2.65 t*hm-2.2)砍伐将使兴安落叶松林生物量和生产力下降,土壤碳含量则有所增加.干扰强度越大则其植物总生物量、生产力和土壤碳含量变化幅度越大,伐后恢复时间也越长.3)连年去除枯枝落叶处理使兴安落叶松林土壤碳含量下降,土壤越来越贫瘠.植物总生物量在前30年迅速增加,之后则趋于稳定.生产力在去除枯枝落叶的前10年增加,之后则逐渐下降,到100年时与不去除枯枝落叶的森林生产力相近.不同枯枝落叶去除强度影响之间没有显著差异.%We applied CENTURY model (version 4.0) to simulate the impacts of forestry management practices on the carbon (C) balance of L. gmelini (Dahurian larch) forest. The model was validated using the observed data of L. gmelini forest ecosystem. The results indicated that L. gmelini forest served as a net C sink of about 2.65 t*hm-2*a-1 at present. Forest felling decreased the gross plant biomass and NPP while increased soil C content. When the harvesting rate was increased, the magnitude of the change (increase or decrease) of the forest gross plant biomass, NPP and soil C content increased and more time was required for its restoration. Annually removal of litter decreased the soil C content and increased the gross plant biomass of L. gmelini forest. NPP increased in the first 10 years and then decreased gradually. After 100 years, it was close to the NPP of the forest without litter removal. There were no significant differences among the impacts of different removal intensities.