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火作为森林生态系统重要的自然干扰因子之一,对森林的碳动态有着不可忽视的影响.本研究使用CENTURY模型模拟了大兴安岭呼中林区兴安落叶松林的碳收支对不同强度火烧的响应.结果表明:在不同强度火烧后,土壤总碳库呈先升后降再逐渐恢复的变化趋势,而林分生物碳库则先降后升,其中,林分细小组分碳库的恢复速度明显快于大组分,各碳库的波动程度随火烧强度的增大而增大.森林植被的净初级生产力(NPP)和土壤异养呼吸在火后均先降后升,但NPP的恢复快于土壤异养呼吸,二者的动态变化改变了林分的碳源/汇作用.轻微火烧后,兴安落叶松林仍表现为弱碳汇,并很快恢复到火前水平;其他强度的火烧使兴安落叶松林在短期内(9“12年)表现为碳源,随后逐渐转为碳汇.较低强度的林火不仅可以促进落叶松林的更新、减少死可燃物,也不会对林分的碳汇功能造成太大影响;高强度的严重林火对土壤和林木碳库造成严重损失,延缓森林的恢复,并可使林分表现为较长时间的碳源.
As an important natural disturbance factor of forest ecosystem, fire has a significant impact on forest carbon dynamics.This study uses the CENTURY model to simulate the carbon budget of Larix gmelinii forest in Huzhong forest area of Daxinganling in response to different intensity of fire. The results showed that the soil total carbon stocks increased at first, then decreased gradually and then recovered gradually after burning at different intensities, while the stand bio-carbon pool first decreased and then rose, and the recovery speed of the sub-component carbon stocks was significantly higher Faster than the major components, the volatility of carbon pools increased with the increase of fire intensity.The net primary productivity (NPP) and soil heterotrophic respiration of forest vegetation firstly decreased and then increased after the fire, but the recovery of NPP In the heterotrophic respiration of soil, the dynamic changes of the two changed the carbon source / sink effect of the stand.After slight fire, the Larix gmelinii forest still showed weak carbon sink, and quickly returned to the pre-fire level. Other intensities of fire Larix gmelinii forest in the short term (9 ”12 years) as a carbon source, and then gradually converted to carbon sinks.Lower intensity of forest fires can not only promote the regeneration of larch forests, reduce dead combustibles, nor will the stand Carbon sink function caused too much impact; Severe forest fires with high intensity have caused serious losses to soil and forest carbon stocks, slowing the recovery of forests and making the stand a carbon source for a longer period of time.