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对重要干扰过程导致森林植被向大气中的碳排放量进行评估,对于合理评估森林碳汇功能及其在应对全球气候变化中的作用是有重要意义的。本文基于有关森林干扰发生情况的林业统计资料和有关干扰引起生物量C转移过程与比例的假设条件,估算了近20年来采伐、火灾与病虫鼠害三种主要干扰每年从森林植被直接排放到大气中的C量。结果表明,近20年来,中国森林遭受了比较强烈的采伐、火灾与病虫鼠害干扰,并且这三种干扰在进入21世纪后有着比较明显的增加趋势。相应地,在1990-2009年间,采伐、火灾与病虫鼠害的C排放量年均分别为3425.16万tC、161.29万tC、428.80万tC,合计为4015.24万t。三种干扰的总C排放量在1990-1999年间年均为3079.40万t,在2000-2009年间年均为4951.09万t。从不同森林类型分布区的排放来看,中国森林主要干扰的年均C排放量及其年代际变化呈现比较明显的区域特征。干扰对中国森林碳平衡有着重大影响,针对干扰的森林管理可能具有较大的增汇潜力,并且在未来有关森林与陆地生态系统碳收支的模型研究中需考虑主要干扰的影响。
The assessment of carbon emissions from forest vegetation to the atmosphere by important disturbing processes is of great importance for the proper assessment of forest carbon sequestration and its role in addressing global climate change. Based on the forestry statistical data on the occurrence of forest disturbance and the assumptions about the process and proportion of the biomass C transfer caused by disturbance, this paper estimates that the three major disturbances of harvesting, fire and pest and rodent pests in the recent 20 years are directly discharged from the forest vegetation to C in the atmosphere. The results show that in the past two decades, the forests of China suffered relatively strong felling, fire and pest, pest and rodent disturbances, and these three kinds of disturbances have a clear trend of increasing after they entered the 21st century. Correspondingly, C emissions from harvesting, fires and pest, rodent pests were 34,251,600 tC, 1,612,900 tC and 42,880,000 tC, respectively, for a total of 40,152,400 t between 1990 and 2009. The total C emissions of the three types of interference averaged 30,740,400 t between 1990 and 1999 and 49,510,900 t between 2000 and 2009 respectively. According to the emission of different types of forests, the annual average C emissions and their interdecadal variations of the major disturbances in forests in China show obvious regional characteristics. Interference has a significant impact on China’s forest carbon balance. Interference-prone forest management may have greater potential for increasing sinks, and the impact of major disturbances should be considered in future model studies on carbon budget for forest and terrestrial ecosystems.