This paper provides a systematic evaluation of the ability of 12 Earth System Models(ESMs)participating in the Coupled Model Intercomparison Project Phase 6(CMIP6)to simulate the spatial inhomogeneity of the atmospher...This paper provides a systematic evaluation of the ability of 12 Earth System Models(ESMs)participating in the Coupled Model Intercomparison Project Phase 6(CMIP6)to simulate the spatial inhomogeneity of the atmospheric carbon dioxide(CO_(2))concentration.The multi-model ensemble mean(MME)can reasonably simulate the increasing trend of CO_(2) concentration from 1850 to 2014,compared with the observation data from the Scripps CO_(2) Program and CMIP6 prescribed data,and improves upon the CMIP5 MME CO_(2) concentration(which is overestimated after 1950).The growth rate of CO_(2) concentration in the northern hemisphere(NH)is higher than that in the southern hemisphere(SH),with the highest growth rate in the mid-latitudes of the NH.The MME can also reasonably simulate the seasonal amplitude of CO_(2) concentration,which is larger in the NH than in the SH and grows in amplitude after the 1950s(especially in the NH).Although the results of the MME are reasonable,there is a large spread among ESMs,and the difference between the ESMs increases with time.The MME results show that regions with relatively large CO_(2) concentrations(such as northern Russia,eastern China,Southeast Asia,the eastern United States,northern South America,and southern Africa)have greater seasonal variability and also exhibit a larger inter-model spread.Compared with CMIP5,the CMIP6 MME simulates an average spatial distribution of CO_(2) concentration that is much closer to the site observations,but the CMIP6-inter-model spread is larger.The inter-model differences of the annual means and seasonal cycles of atmospheric CO_(2) concentration are both attributed to the differences in natural sources and sinks of CO_(2) between the simulations.展开更多
Pinus Syvestfiformis is an important species as an indicator of global climate changes in Changbai Mountain, China. The water use efficiency (WUE) of this species (11 -year old ) was studied on response to elevated Co...Pinus Syvestfiformis is an important species as an indicator of global climate changes in Changbai Mountain, China. The water use efficiency (WUE) of this species (11 -year old ) was studied on response to elevated Co, concentration at 500±μLL' L-1 by directly injecting CO2 into the canopy under natural condition in 1998-1999. The results showed that the elevated Co, concentration reduced averagely stomatal opening, stomatal conductance and stomatal density to 78%, 80% and 87% respectively, as compared to normal ambient. The elevated Co, reduced the transpiration and enhances the water use efficiency (WUE) of plant.展开更多
The impacts of elevated temperature and COon young silver birch(Betula pendula Roth) saplings after 0,25, 50 or 75% artificial defoliation were assessed by measuring plant height and dry mass of aboveground compartmen...The impacts of elevated temperature and COon young silver birch(Betula pendula Roth) saplings after 0,25, 50 or 75% artificial defoliation were assessed by measuring plant height and dry mass of aboveground compartments and roots and various morphological and physiological variables. Defoliation either increased or decreased plant growth depending on the severity of damage and the climatic treatment. At 21 °C and400 mg LCO, defoliated plants were not able to compensate for the lost foliage, but growth compensation and adaptation to the changed conditions were greater; growth of young defoliated silver birch saplings increased, which led to increased height and a tendency to enhance final aboveground and root biomass and leaf nitrogen and carbon content compared to the nondefoliated controls. Nevertheless, the short-term effect of the different climatic conditions did not result in a significant overgrowth of defoliated plants. A slight increase in temperature and COwere the most acceptable conditions for defoliated plants;however, a 4 °C increase with correspondingly higher COwas more stressful as shown by less growth in height and biomass allocation to leaves, stems and roots. The findings from the pilot experiment are more applicable to young birch trees, but stress on young trees may be reflected in future tree growth.展开更多
地球系统模式结果表明大气CO_(2)浓度的快速增加是气候变化重要的原因之一。卫星资料分析结果表明,大气CO_(2)浓度并非均一的,而是有明显的区域差异,以人类活动为主的碳排放会影响这一区域差异。这种空间差异如何影响区域地表气温对CO_...地球系统模式结果表明大气CO_(2)浓度的快速增加是气候变化重要的原因之一。卫星资料分析结果表明,大气CO_(2)浓度并非均一的,而是有明显的区域差异,以人类活动为主的碳排放会影响这一区域差异。这种空间差异如何影响区域地表气温对CO_(2)的敏感度,需要进一步深入系统的研究,利用地球系统模式BNU-ESM(Earth System Model of Beijing Normal University)进行数值模拟,并与观测数据进行比较,结果表明:在试验模拟结果2°C阈值内,非均匀CO_(2)浓度试验的CO_(2)浓度增加阈值范围小于均匀CO_(2)浓度试验结果,偏少约为4.3 ppm(106)。在区域尺度上,中国地表气温对CO_(2)敏感度普遍低于美国、欧洲以及北半球平均水平,这表明CO_(2)浓度空间差异对地表气温的敏感度的影响存在明显区域差异,很可能是CO_(2)浓度辐射效应与气候系统反馈过程的共同作用结果,这需要进一步研究。非均匀CO_(2)浓度对地表气温敏感度影响将会对碳中和目标下未来碳汇潜力精准估算提供科学支持。展开更多
为揭示未来气候变化趋势对稻谷Fe、Zn含量和积累量的影响,本研究利用开顶式气室(Open Top Chamber,OTC)系统模拟大气CO_(2)浓度上升(EC处理,+100μL·L^(-1))和增温(ET处理,+1.5℃)以及二者相互作用(ETEC处理,+1.5℃,+100μL·L...为揭示未来气候变化趋势对稻谷Fe、Zn含量和积累量的影响,本研究利用开顶式气室(Open Top Chamber,OTC)系统模拟大气CO_(2)浓度上升(EC处理,+100μL·L^(-1))和增温(ET处理,+1.5℃)以及二者相互作用(ETEC处理,+1.5℃,+100μL·L^(-1))的气候变化情景,对江汉平原2017—2019年双季稻籽粒Fe、Zn以及植酸含量进行持续3 a的大田试验观测。结果表明:双季稻籽粒Fe和Zn含量对大气CO_(2)浓度上升与增温的响应存在较大的年际间差异,其中对大气CO_(2)浓度上升的响应较增温更为敏感。与对照(CK)相比,EC处理显著降低2018年晚稻籽粒Fe含量(-13.41%,P<0.05),显著增加2019年早稻和晚稻籽粒Fe含量(+29.70%和+27.95%,P<0.05);ET处理显著降低2018年早稻籽粒Zn含量(-13.49%,P<0.05)。就3 a观测平均值而言,EC处理显著降低早稻籽粒Zn含量(-8.28%,P<0.05),而ETEC处理显著降低晚稻籽粒Zn含量(-10.91%,P<0.05)。本研究发现CO_(2)浓度上升与增温叠加作用效果有别于各单因子影响,尤其对高温干旱年份晚稻籽粒Zn含量的降低具有显著的正协同效应。本研究预测未来气候变化可能增加稻米食用人口出现“隐性饥饿”的风险。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42230608)the UK-China Research&Innovation Partnership Fund through the Met Office Climate Science for Service Partnership(CSSP)China as part of the Newton Fund.
文摘This paper provides a systematic evaluation of the ability of 12 Earth System Models(ESMs)participating in the Coupled Model Intercomparison Project Phase 6(CMIP6)to simulate the spatial inhomogeneity of the atmospheric carbon dioxide(CO_(2))concentration.The multi-model ensemble mean(MME)can reasonably simulate the increasing trend of CO_(2) concentration from 1850 to 2014,compared with the observation data from the Scripps CO_(2) Program and CMIP6 prescribed data,and improves upon the CMIP5 MME CO_(2) concentration(which is overestimated after 1950).The growth rate of CO_(2) concentration in the northern hemisphere(NH)is higher than that in the southern hemisphere(SH),with the highest growth rate in the mid-latitudes of the NH.The MME can also reasonably simulate the seasonal amplitude of CO_(2) concentration,which is larger in the NH than in the SH and grows in amplitude after the 1950s(especially in the NH).Although the results of the MME are reasonable,there is a large spread among ESMs,and the difference between the ESMs increases with time.The MME results show that regions with relatively large CO_(2) concentrations(such as northern Russia,eastern China,Southeast Asia,the eastern United States,northern South America,and southern Africa)have greater seasonal variability and also exhibit a larger inter-model spread.Compared with CMIP5,the CMIP6 MME simulates an average spatial distribution of CO_(2) concentration that is much closer to the site observations,but the CMIP6-inter-model spread is larger.The inter-model differences of the annual means and seasonal cycles of atmospheric CO_(2) concentration are both attributed to the differences in natural sources and sinks of CO_(2) between the simulations.
文摘Pinus Syvestfiformis is an important species as an indicator of global climate changes in Changbai Mountain, China. The water use efficiency (WUE) of this species (11 -year old ) was studied on response to elevated Co, concentration at 500±μLL' L-1 by directly injecting CO2 into the canopy under natural condition in 1998-1999. The results showed that the elevated Co, concentration reduced averagely stomatal opening, stomatal conductance and stomatal density to 78%, 80% and 87% respectively, as compared to normal ambient. The elevated Co, reduced the transpiration and enhances the water use efficiency (WUE) of plant.
基金financially supported by the Longterm Research Programme ‘‘Sustainable Forestry and Global Changes’’ implemented by the Lithuanian Research Centre for Agriculture and Forestry
文摘The impacts of elevated temperature and COon young silver birch(Betula pendula Roth) saplings after 0,25, 50 or 75% artificial defoliation were assessed by measuring plant height and dry mass of aboveground compartments and roots and various morphological and physiological variables. Defoliation either increased or decreased plant growth depending on the severity of damage and the climatic treatment. At 21 °C and400 mg LCO, defoliated plants were not able to compensate for the lost foliage, but growth compensation and adaptation to the changed conditions were greater; growth of young defoliated silver birch saplings increased, which led to increased height and a tendency to enhance final aboveground and root biomass and leaf nitrogen and carbon content compared to the nondefoliated controls. Nevertheless, the short-term effect of the different climatic conditions did not result in a significant overgrowth of defoliated plants. A slight increase in temperature and COwere the most acceptable conditions for defoliated plants;however, a 4 °C increase with correspondingly higher COwas more stressful as shown by less growth in height and biomass allocation to leaves, stems and roots. The findings from the pilot experiment are more applicable to young birch trees, but stress on young trees may be reflected in future tree growth.
文摘地球系统模式结果表明大气CO_(2)浓度的快速增加是气候变化重要的原因之一。卫星资料分析结果表明,大气CO_(2)浓度并非均一的,而是有明显的区域差异,以人类活动为主的碳排放会影响这一区域差异。这种空间差异如何影响区域地表气温对CO_(2)的敏感度,需要进一步深入系统的研究,利用地球系统模式BNU-ESM(Earth System Model of Beijing Normal University)进行数值模拟,并与观测数据进行比较,结果表明:在试验模拟结果2°C阈值内,非均匀CO_(2)浓度试验的CO_(2)浓度增加阈值范围小于均匀CO_(2)浓度试验结果,偏少约为4.3 ppm(106)。在区域尺度上,中国地表气温对CO_(2)敏感度普遍低于美国、欧洲以及北半球平均水平,这表明CO_(2)浓度空间差异对地表气温的敏感度的影响存在明显区域差异,很可能是CO_(2)浓度辐射效应与气候系统反馈过程的共同作用结果,这需要进一步研究。非均匀CO_(2)浓度对地表气温敏感度影响将会对碳中和目标下未来碳汇潜力精准估算提供科学支持。
文摘为揭示未来气候变化趋势对稻谷Fe、Zn含量和积累量的影响,本研究利用开顶式气室(Open Top Chamber,OTC)系统模拟大气CO_(2)浓度上升(EC处理,+100μL·L^(-1))和增温(ET处理,+1.5℃)以及二者相互作用(ETEC处理,+1.5℃,+100μL·L^(-1))的气候变化情景,对江汉平原2017—2019年双季稻籽粒Fe、Zn以及植酸含量进行持续3 a的大田试验观测。结果表明:双季稻籽粒Fe和Zn含量对大气CO_(2)浓度上升与增温的响应存在较大的年际间差异,其中对大气CO_(2)浓度上升的响应较增温更为敏感。与对照(CK)相比,EC处理显著降低2018年晚稻籽粒Fe含量(-13.41%,P<0.05),显著增加2019年早稻和晚稻籽粒Fe含量(+29.70%和+27.95%,P<0.05);ET处理显著降低2018年早稻籽粒Zn含量(-13.49%,P<0.05)。就3 a观测平均值而言,EC处理显著降低早稻籽粒Zn含量(-8.28%,P<0.05),而ETEC处理显著降低晚稻籽粒Zn含量(-10.91%,P<0.05)。本研究发现CO_(2)浓度上升与增温叠加作用效果有别于各单因子影响,尤其对高温干旱年份晚稻籽粒Zn含量的降低具有显著的正协同效应。本研究预测未来气候变化可能增加稻米食用人口出现“隐性饥饿”的风险。
文摘选择造林树种大叶相思(Acacia auriculiformis)和樟树(Cinnamomum camphora)为对象,采用开顶生长箱(open-top chamber,OTC)构建实验林,探讨镉(Cd)胁迫及其与大气CO_(2)浓度升高、氮(N)添加的复合作用对2种树木叶片N、P养分利用策略和Cd积累特征的影响。试验设5个处理:对照(CK)、加Cd[10 kg Cd/(hm^(2)·a)](Cd)、加Cd与加CO_(2)(700μmol/mol)(CdC)、加Cd与加N[100 kg N/(hm^(2)·a)](CdN)、加Cd加CO_(2)加N(CdCN)。处理约2.5 a后,测定两树种的成熟叶和衰老叶中N、磷(P)和Cd含量。结果表明,不同处理对两树种叶片P含量及P回收率均无显著影响,但显著影响叶片N含量及N回收率;CdN处理下两树种叶片N含量升高;Cd和CdN处理下樟树叶N回收率显著降低。Cd、CdC、CdN和CdCN处理下两树种叶片Cd积累浓度及樟树成熟叶中的Cd/N和Cd/P升高。大叶相思叶片N、P回收率显著高于樟树,Cd积累浓度显著低于樟树。速生豆科固氮树种大叶相思比普通非固氮树种樟树具有更好的N、P养分利用策略和抵御叶片积累Cd的能力,表明大叶相思可以作为Cd污染林地土壤生态修复的适宜树种。
