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Effect of Root-Induced Chemical changes on Dynamics and Plant Uptake of Heavy Metals in Rhizosphere Soils

Pedosphere 2010年第4期20卷 494-504页

作者： K.R.KIM G.OWENS R.NAIDU climate change & Agroecology Division Department of Agricultural EnvironmentNational Academy of Agricultural Science centre for Environmental Risk Assessment and Remediation University of South Australia Cooperative research centre for Contamination Assessment and Remediation of the Environment

It is increasingly recognized that metal bioavailability is a better indicator of the potential for phytoremediation than the total metal concentration in soils; therefore, an understanding of the influence of phytoremediation plants on metal dynamics at the soil-root interface is increasingly vital for the successful implementation of this remediation technique. In this study, we investigated the heavy metal and soil solution chemical changes at field moisture, after growth of either Indian mustard （Brassica juncea） or sunflower （Helianthus annuus L.）, in long-term contaminated soils and the subsequent metal uptake by the selected plants. In addition, the fractions of free metal ions in soil solution were determined using the Donnan membrane technique. After plant growth soil solution pH increased by 0.2-1.4 units and dissolved organic carbon （DOC） increased by 1-99 mg L^-1 in all soils examined. Soluble Cd and Zn decreased after Indian mustard growth in all soils examined, and this was attributed to increases in soil solution pH （by 0.9 units） after plant growth. Concentrations of soluble Cu and Pb decreased in acidic soils but increased in alkaline soils. This discrepancy was likely due to a competitive effect between plant-induced pH and DOC changes on the magnitude of metal solubility. The fractions of free Cd and Zn ranged from 7.2% to 32% and 6.4% to 73%, respectively, and they generally decreased as pH and DOC increased after plant growth. Metal uptake by plants was dependant on the soil solution metal concentration, which was governed by changes in pH and DOC induced by plant exudates, rather than on the total metal concentrations. Although plant uptake also varied with metal and soil types, overall soluble metal concentrations in the rhizosphere were mainly influenced by root-induced changes in pH and DOC which subsequently affected the metal uptake by plants.

关键词： bioavailability phytoremediation speciation

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China's pre-2020 CO2 emission reduction potential and its influence

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Frontiers in Energy 2019年第3期13卷 571-578页

作者： Hailin WANG Jiankun HE Institute of Energy Environment and Economy Institute of Climate Change and Sustainable DevelopmentTsinghua UniversityBeijing 100084China Institute of Energy Environment and Economy Modem Management Research CenterInstitute of Climate Change and Sustainable DevelopmentTsinghua UniversityBeijing 100084China

China achieved the reduction of CO2 intensity of GDP by 45% compared with 2005 at the end of 2017, realizing the commitment at 2009 Copenhagen Conference on emissions reduction 3 years ahead of time. In future implementation of the "13th Five-Year Plan (FYP)," with the decline of economic growth rate, decrease of energy consumption elasticity and optimization of energy structure, the CO2 intensity of GDP will still have the potential for decreasing before 2020. By applying KAYA Formula decomposition, this paper makes the historical statistics of the GDP energy intensity decrease and CO2 intensity of energy consumption since 2005, and simulates the decrease of CO2 intensity of GDP in 2020 and its influences on achieving National Determined Contribution (NDC) target in 2030 with scenario analysis. The results show that China's CO2 intensity of GDP in 2020 is expected to fall by 52.9%-54.4% than the 2005 level, and will be 22.9%-25.4% lower than 2015. Therefore, it is likely to overfulfill the decrease of CO2 intensity of GDP by 18% proposed in the 13th FYP period. Furthermore, the emission reduction potentiality before 2020 will be conducive to the earlier realization of NDC objectives in 2030. China's CO2 intensity of GDP in 2030 will fall by over 70% than that in 2005, and CO2 emissions peak will appear before 2030 as early as possible. To accelerate the transition to a low-carbon economy, China needs to make better use of the carbon market, and guide the whole society with carbon price to reduce emissions effectively. At the same time, China should also study the synergy of policy package so as to achieve the target of emission reduction.

关键词： China's National Determined Contribution emission reduction potential scenario analysis CO2 emissions peak

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Comparison of convective parameterizations in RegCM4 experiments over China with CLM as the land surface model

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Atmospheric and Oceanic Science Letters 2016年第4期9卷 246-254页

作者： GAO Xue-Jie SHI Ying Filippo GIORGI climate change research Center Institute of Atmospheric Physics Chinese Academy of Sciences National climate Center China Meteorological Administration The Abdus Salam International centre for Theoretical Physics

in the latest version of the international centre for Theoretical Physics＇ regional climate model, RegCM4, CLM was introduced as a new land surface scheme. The performance over China of RegCM4-CLM with different convection schemes is analyzed in this study, based on a series of short- term *** model is driven by ERA-Interim data at a grid spacing of 25 *** convection schemes employed are： Emanuel; Grell; Emanuel over land and Grell over ocean; Grell over land and Emanuel over ocean; and Tiedtke. The simulated mean surface air temperature and precipitation in December-February-January and June-July-August are compared against observation. In general, better performance of Emanuel is found both for temperature and precipitation, and in both seasons. Thus, the model physics of CLM and Emanuel for the land surface processes and convection, respectively, are recommended for further application of RegCM4 over the China region. The de^ciencies that remain in the model arealso outlined and discussed.

关键词： Regional climate model China RegCM4 temperatureprecipitation

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Variability of Northeast China River Break-up Date

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Advances in Atmospheric Sciences 2009年第4期26卷 701-706页

作者：王会军孙建奇 Institute of Atmospheric Physics Chinese Academy of Sciences climate change research Center(CCRC) Chinese Academy of Sciences

This paper investigates the variability of the break-up dates of the rivers in Northeast China from their icebound states for the period of 1957-2005 and explores some potential explanatory mechanisms. Results show that the break-up of the two major rivers （the Heilongjiang River and Songhuajiang River） was about four days earlier, and their freeze-up was about 4-7 days delayed, during 1989 2005 as compared to 1971 1987. This interdecadal variation is evidently associated with the warming trend over the past 50 years. In addition, the break-up and freeze-up dates have large interannual variability, with a standard deviation of about 10-15 days. The break-up date is primarily determined by the January February-March mean surface air temperature over the Siberian-Northeast China region via changes in the melting rate, ice thickness, and snow cover over the ice cover. The interannual variability of the break-up date is also significantly connected with the Northern Annular Mode （NAM）, with a correlation coefficient of 0.35-0.55 based on the data from four stations along the two rivers. This relationship is attributed to the fact that the NAM can modulate the East Asian winter monsoon circulation and Siberian-Northeast China surface air temperature in January February-March.

关键词： river icebound season interdecadal variation interannual variability northern annular mode

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Potential impacts of enhanced tropical cyclone activity on the El Ni?o–Southern Oscillation and East Asian monsoon in the mid-Piacenzian warm period

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Atmospheric and Oceanic Science Letters 2019年第1期12卷 1-11页

作者： YAN Qing ZHANG Zhongshi ZHANG Ran Nansen-Zhu International research centre Institute of Atmospheric Physics Chinese Academy of Sciences Department of Atmospheric Science School of Environmental Studies China University of Geosciences Bjerknes Center for climate research Uni Research Climate climate change research Center Chinese Academy of Sciences

Tropical cyclones(TCs)not only passively respond to climate change,but also play an important role in vertical mixing of the upper ocean and in driving oceanic heat *** a fully coupled climate model,the authors investigate the potential effect of TC-induced vertical mixing on the El Nino–Southern Oscillation(ENSO)and East Asian monsoon in the mid-Piacenzian,during which global TCs are estimated to have been *** experiments indicate that the TC-induced oceanic mixing over global storm basins leads to additional warming over the eastern tropical Pacific and a deeper thermocline in the mid-Piacenzian,whereas it dampens the interannual variability of *** the East Asian monsoon circulations,low-level(850 hPa)summer and winter winds are intensified in response to enhanced vertical mixing,with a southward/westward shift of the western North Pacific high and westerly jet in summer and a deepened East Asian trough in *** climatic features are largely reproduced in the experiment with enhanced vertical mixing only over the central-eastern North *** results may shed light on TC feedbacks associated with vertical mixing and advance our understanding on mid-Piacenzian climate.

关键词： Mid-Piacenzian climate modeling tropical cyclone ENSO

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Interdecadal Variations of Winter Temperatures in East China During the Past 100 Years and Related Atmospheric Circulation

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Atmospheric and Oceanic Science Letters 2013年第5期6卷 290-294页

作者： ZHU Ya-Li Nansen-Zhu International research centre Institute of Atmospheric Physics Chinese Academy of Sciences climate change research Center Chinese Academy of Sciences

The winter temperature changes in East China during the past 100 years are investigated by using the Twentieth Century Version 2(20th-v2)*** typical warm(P1,1911–30;P4,1991–2010)and cold(P2,1938–57;P3,1961–80)periods are identified for the East China winter temperature *** of160-station observational data,NCAR sea level pressure(SLP)data,and NCEP/NCAR Reanalysis shows that the20th-v2 Reanalysis can successfully depict the major features of the warming from P3 to P4,which is part of the global warming *** cooling from P1 to P2is a regional phenomenon under global ***,both changes are consistent with the phase change of the Arctic Oscillation(AO),while the second change is also accompanied by the phase change of Antarctic Oscillation(AAO)from negative to *** sources of the interdecadal shifts of the AO and winter temperature in East China require further research.

关键词： East China winter temperature global warming decadal change

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Vegetation Feedback at the Mid-Pliocene

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Atmospheric and Oceanic Science Letters 2013年第5期6卷 320-323页

作者： JIANG Da-Bang Nansen-Zhu International research centre Institute of Atmospheric Physics Chinese Academy of Sciences climate change research Center Chinese Academy of Sciences

A global atmospheric general circulation model and an asynchronously coupled global atmosphere-biome model are used to simulate vegetation feedback at the mid-Pliocene approximately 3.3 to 3.0 million years *** that period,the simulated vegetation differed from present conditions at 62％ of the global ice-free land *** feedback had little overall impact on the global climate of the *** the regional scale,however,the interactive vegetation led to statistically significant increases in annual temperature over Greenland,the high latitudes of North America,the mid-high latitudes of eastern Eurasia,and westem Tibet,and reductions in most of the land areas at low latitudes,owing to vegetation-induced changes in surface albedo.

关键词： mid-Pliocene vegetation feedback model

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Mid-Holocene Ocean Feedback on Global Monsoon Area and Precipitation

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Atmospheric and Oceanic Science Letters 2015年第1期8卷 29-32页

作者： TIAN Zhi-Ping JIANG Da-Bang climate change research Center Chinese Academy of Sciences Nansen-Zhu International research centre Institute of Atmospheric Physics Chinese Academy of Sciences

Mid-Holocene ocean feedback on global monsoon area, global monsoon precipitation(GMP), and GMP intensity(GMPI) was investigated by a set of numerical experiments performed with the Community climate System Model version 4. Results showed that ocean feedback induced an increase in land monsoon area for northern Africa but a decrease for Asia and North and South America, and led to an increase in ocean monsoon area for the western Indian Ocean and southeastern Pacific but a decrease for the eastern Indian Ocean, tropical western Pacific, and tropical West Atlantic between the mid-Holocene and pre-industrial period. Dynamic oceaninduced changes in GMP and GMPI were 10.9×109 m3 d-1and-0.11 mm d-1 between the two periods, *** feedback induced consistent change between the Northern and Southern Hemisphere land or ocean but opposite change between land and ocean in the Northern or Southern Hemisphere monsoon areas for monsoon precipitation. The mid-Holocene summer changes in meridional temperature gradient and land-sea thermal contrast were the underlying mechanisms.

关键词： Mid-Holocene ocean feedback monsoon area monsoon p

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Chemodynamics of heavy metals in long-term contaminated soils:Metal speciation in soil solution

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Journal of Environmental Sciences 2009年第11期21卷 1532-1540页

作者： Kwon-Rae Kim Gary Owens centre for Environmental Risk Assessment and Remediation University of South Australia climate change & Agroecology Division Department of Agricultural Environment National Academy of Agricultural Science

The concentration and speciation of heavy metals in soil solution isolated from long-term contaminated soils were investigated. The soil solution was extracted at 70% maximum water holding capacity （MWHC） after equilibration for 24 h. The free metal concentrations （Cd^2＋, Cu^2＋, Pb^2＋, and Zn^2＋） in soil solution were determined using the Donnan membrane technique （DMT）. Initially the DMT was validated using artificial solutions where the percentage of free metal ions were significantly correlated with the percentages predicted using MINTEQA2. However, there was a significant difference between the absolute free ion concentrations predicted by MINTEQA2 and the values determined by the DMT. This was due to the significant metal adsorption onto the cation exchange membrane used in the DMT with 20%, 28%, 44%, and 8% mass loss of the initial total concentration of Cd, Cu, Pb, and Zn in solution, respectively. This could result in a significant error in the determination of free metal ions when using DMT if no allowance for membrane cation adsorption was made. Relative to the total soluble metal concentrations the amounts of free Cd^2＋（3%-52%） and Zn^2＋（11%-72%） in soil solutions were generally higher than those of Cu^2＋（0.2%-30%） and Pb^2＋（0.6%-10%）. Among the key soil solution properties, dissolved heavy metal concentrations were the most significant factor governing free metal ion concentrations. Soil solution pH showed only a weak relationship with free metal ion partitioning coefficients （Kp） and dissolved organic carbon did not show any significant influence on Kp.

关键词： Donnan membrane technique free metal ion heavy metals partitioning coefficient solubility speciation

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Physical Mechanism of the Impacts of the Tropical Atlantic Sea Surface Temperature on the Decadal change of the Summer North Atlantic Oscillation

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Atmospheric and Oceanic Science Letters 2013年第5期6卷 365-368页

作者： SUN Jian-Qi Nansen-Zhu International research centre Institute of Atmospheric Physics Chinese Academy of Sciences climate change research Center Chinese Academy of Sciences

In this study,physical mechanism of the impacts of the tropical Atlantic sea surface temperature(SST)on decadal change of the summer North Atlantic Oscillation(SNAO)was explored using an atmospheric general circulation model(AGCM)developed at the International centre for Theoretical Physics(ICTP).The simulation results indicate that the decadal warming of the SST over the tropical Atlantic after the late 1970s could have significantly enhanced the convection over the *** enhanced convection would have strengthened the local meridional circulation over the Eastern Atlantic-North Africa-Western Europe region,exciting a meridional *** teleconnection might have brought the signal of the tropical Atlantic SST to the Extratropics,consequently activating the variability of the eastern part of the SNAO southern center,which led to an eastward shift of the SNAO southern center around the late *** physical processes are highly consistent with the previous observations.

关键词： summer North Atlantic Oscillation tropical Atlantic sea surface temperature teleconnection decadal change simulation

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