摘要
区域尺度陆地植物有氧条件下排放甲烷及其气候效应研究不仅对甲烷收支平衡研究具有重要意义,对于全球变化研究也具有重要推动作用。通过改进Keppler提出的公式,模拟了中国区域植物有氧甲烷排放的时空分布。利用IBIS模拟的NPP数据结合相关文献统计生物量与NPP的比值,计算得到中国区域自然植物叶片生物量,以及叶片甲烷排放。结果显示,2001年至2012年中国植物生物量与植物叶片甲烷排放量在Sres A2和Sres B1两种情景下差异不明显;但是气候变化模式差异的影响会随着时间的推移而扩大。在Sres A2情景下,中国地区年均植物生物量为10803.22Tg C,叶片生物量为1156.15Tg C。如果不考虑天气对光照的影响,植物叶片甲烷排放年均2.69Tg,约是全国年甲烷排放总量7.01%,是中国稻田甲烷排放总量的29.05%。在各植被类型中,草地叶片甲烷排放量最高,达到47.53%,其次是混交林。森林(针叶林、阔叶林、混交林)是主要的植物甲烷排放源,占中国区域植物甲烷排放总量的51.28%,其次是草地,占47.47%。中国区域植物叶片甲烷排放南高北低,东高西低的分布状态主要由地表植被覆盖类型决定,光照和温度也是重要影响因素。对Sres A2和Sres B1两种气候情景下中国植物甲烷排放预测分析,中国区域植物甲烷排放不断增加,在Sres A2情景下不同时期的平均增长率为9.73%,高于Sres B1情景的5.17%,且两种情景下的增长率都在降低。21世纪Sres A2和Sres B1变化情景下,年均植物排放的甲烷CO_2当量分别为83.18Tg和77.34Tg,约占中国年均CO_2排放总量的1.39%和1.29%。
Until recently, it was commonly accepted in the scientific anaerobic conditions through microbial metabolism. However, in 2006, from plants under aerobic conditions. Subsequent experimental studies from plants, and that the emission rate of aerobic methane is constant community that methane was produced only under Keppler et al. showed that methane can be released have demonstrated that aerobic methane is released at a given temperature demonstrate biomass may bethe source of plant aerobic methane. Although the exact mechanism underlying plant aerobic methane emission has not been identified to date, these experiments suggest that it is dependent on light and temperature. Over the past 20 years, atmospheric methane content has decreased due to an unknown mechanism and there seems to be an unidentified methane source, which may be related to plant aerobic methane emissions. Thus, quantitative research on methane emissions from plants under aerobic conditions and its effects on climate are critical to calculating a global methane budget. Based on a modified Keppler＇s model and net primary productivity （NPP） simulated by the Integrated Biosphere Simulator （IBIS）, this study simulates and predicts spatial and temporal variation in methane emissions from terrestrial plants under aerobic conditions in China. It then rebuilds patterns of plant aerobic methane emission suited for China with leaf biomass, and explores the spatial and temporal characteristics of terrestrial plant aerobic methane emissions and variations in emissions among plant types. We also simulated the effect of aerobic methane emissions on climate change, especially the greenhouse effect, under different scenarios, e.g., doubled CO2. Biomass accumulation ratios, which were used to establish quantitative relationships between NPP and biomass, and ratios of leaves and intact plant biomass were collected from previous studies. Although simulated biomass and methane emissions 2001 and 2012, significant differences between them under the IPCC sce
出处
《生态学报》
CAS
CSCD
北大核心
2016年第3期580-591,共12页
Acta Ecologica Sinica
基金
博士点基金资助(20100091120017)
国家自然科学基金项目(41471343)
