气候变化、林火和采伐对大兴安岭森林碳储量的影响

大兴安岭林区林火发生的频率受气候变化的影响将会增加,可能会增加该地区森林生态系统碳损失.本研究通过耦合森林生态系统模型和森林景观模型以模拟未来百年大兴安岭森林碳储量动态变化,量化气候变化、林火和采伐对森林碳储量的影响.结果表明: 虽然采伐和林火会抵消相当一部分由气候变化增加的碳储量,但气候变化仍然能够增加大兴安岭森林碳储量.未来100年该地区森林地上和土壤有机碳储量将会分别增加9%～22%和6%～9%.短期(0～20年)气候变化对大兴安岭森林碳储量的影响大于同期林火的影响,中期(30～50年)和长期(60～100年)气候变化对森林碳储量的影响小于林火和采伐的影响.由于未来大兴安岭地区气候变化及其林火干扰存在不确定性,导致未来该地区森林碳储量存在较大的不确定性.未来100年大兴安岭森林地上碳储量和土壤有机碳储量不确定性分别为12.4%～16.2%和6.6%～10.4%.为准确估算我国北方森林生态系统碳储量,需要考虑种子传播、林火和采伐的影响.

Effects of climate change,fire and harvest on carbon storage of boreal forests in the Great Xing’an Mountains,China.

Climate change will increase the frequency of fire disturbances, which may further exa-cerbate carbon loss from boreal forests in the Great Xing’an Mountains, China. In this study, we coupled forest ecosystem and forest landscape models to simulate the dynamics of boreal forest carbon storage in the next 100 years. We quantified the effects of climate change, fire and harvest on carbon storage of boreal forests. The results showed that climate change would increase carbon storage of boreal forests in the Great Xing’an Mountains, even if fire and harvest could partially offset such changes. Aboveground and soil organic carbon storage would increase by 9%-22% and 6%-9% in the next 100 years. In the short-term (0-20 years), the effects of climate change on carbon storage was stronger than fire. The effects of climate change on boreal forest carbon storage were less than fire and harvest in medium (30-50 years) and long-term (60-100 years). The variability of climate change and fire disturbance in the Great Xing’an Mountains caused high uncertainty of the future boreal forest carbon storage. The uncertainties of aboveground and soil organic carbon of boreal forests in the Great Xing’an Mountains were 12.4%-16.2% and 6.6%-10.4% in the next 100 years. The effects of seed dispersal, fire and harvest should be taken account for accurate estimation of carbon storage in Chinese boreal forests.