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Estimation of diffuse photosynthetically active radiation and the spatiotemporal variation analysis in China from 1981 to 2010

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Journal of Geographical Sciences 2014年第4期24卷 579-592页

作者： REN Xiaoli HE Honglin ZHANG Li YU Guirui Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China

Photosynthetically active radiation （PAR） is the energy source of plant photosyn thesis, and the diffuse component can enhance canopy light use efficiency, thereby increasing the carbon uptake. Therefore, diffuse PAR is an important driving factor of ecosystem productivity models. In this study, we estimated the diffuse PAR of over 700 meteorological sites in China from 1981 to 2010 using an empirical model based on observational data from Chinese ecosystem Research network （CERN） and China Meteorology Administration. Then we derived the spatial data set of 10 km monthly diffuse PAR using ANUSPLIN software, and analyzed the spatiotemporal variation characteristics of diffuse PAR through GIS and trend analysis techniques. The results showed that：（1） The spatial patterns of annual average diffuse PAR during 1981-2010 are heterogeneous across China, lower in the northeast and higher in the west and south. The nationwide average value for 30 years ranges from 6.66 mol m-2 d-1 to 15.27 mol m-2 d-1, and the value in summer is the biggest while the value in winter is the smallest. （2） There is an evident increasing trend of annual diffuse PAR during recent 30 years, with the increasing amplitude at 0.03 mol m-2 d-l/10a. But a significant declining trend is shown in the first 10 years, and obvious anomalies can be seen in 1982, 1983, 1991 and 1992. And there is a downtrend in spring and an uptrend in all the other seasons. （3） The spatial distribution of temporal variation rates of diffuse PAR is inhomogeneous across the country, generally decreasing in the north and increasing in the south.

关键词： photosynthetically active radiation （PAR） diffuse fraction diffuse PAR spatiotemporal variations

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Nitrogen Deposition and Its Spatial Pattern in Main Forest ecosystems along North-South Transect of Eastern China

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Chinese Geographical Science 2014年第2期24卷 137-146页

作者： ZHAN Xiaoyun YU Guirui HE Nianpeng FANG Huajun JIA Bingrui ZHOU Mei WANG Chuankuan ZHANG Junhui ZHAO Guangdong WANG Silong LIU Yunfen YAN Junhua Synthesis Research Center of Chinese Ecosystem Research Network Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences University of Chinese Academy of Sciences Institute of Botany Chinese Academy of Sciences College of Ecology and Environmental Science Inner Mongolia Agricultural University College of Forestry Northeast Forestry University Institute of Applied Ecology Chinese Academy of Sciences Institute of Forest Ecology Environment and Protection Chinese Academy of Forestry South China Botany Garden Chinese Academy of Sciences

A continuous three-year observation(from May 2008 to April 2011)was conducted to characterize the spatial variation of dissolved inorganic nitrogen(DIN)deposition at eight main forest ecosystems along the north-south transect of eastern China(NSTEC).The results show that both throughfall DIN deposition and bulk DIN deposition increase from north to south along the *** DIN deposition varies greatly from 2.7 kg N/(ha·yr)to 33.0 kg N/(ha·yr),with an average of 10.6 kg N/(ha·yr),and bulk DIN deposition ranges from 4.1 kg N/(ha·yr)to 25.4 kg N/(ha·yr),with an average of 9.8 kg N/(ha·yr).NH4+-N is the dominant form of DIN deposition at most sampling ***,the spatial variation of DIN deposition is controlled mainly by ***,in the northern part of the NSTEC,bulk DIN deposition is 17%higher than throughfall DIN deposition,whereas the trend is opposite in the southern part of the *** results demonstrate that DIN deposition would likely threaten the forest ecosystems along the NSTEC,compared with the critical loads(CL)of N deposition,and DIN deposition in this region is mostly controlled by agricultural activities rather than industrial activities or transportation.

关键词： forest ecosystem nitrogen deposition NH4＋-N NO3-N eastern China

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Temporal variations of atmospheric water vapor δD and δ¹⁸O above an arid artificial oasis cropland in the Heihe River Basin

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JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 2014年第19期119卷 11456-11476页

作者： Huang, Lvjun Wen, Xuefa Chinese Acad Sci Key Lab Ecosystem Network Observat & Modeling Inst Geog Sci & Nat Resources Res Beijing Peoples R China Univ Chinese Acad Sci Coll Nat Resources & Environm Beijing Peoples R China

The high temporal resolution measurements of delta D, delta O-18, and deuterium excess (d) of atmospheric water vapor provide an improved understanding of atmospheric and ecohydrological processes at ecosystem to global scales. In this study, delta D, delta O-18, and d of water vapor and their flux ratios were continuously measured from May to September 2012 using an in situ technique above an arid artificial oasis in the Heihe River Basin, which has a typical continental arid climate. The monthly delta D and delta O-18 increased slowly and then decreased, whereas the monthly d showed a steady decrease. delta D, delta O-18, and d exhibited a marked diurnal cycle, indicating the influence of the entrainment, local evapotranspiration (ET), and dewfall. The departures of delta D, delta O-18, and d from equilibrium prediction were significantly correlated with rain amount, relative humidity (RH), and air temperature (T). The "amount effect" was observed during one precipitation event. delta D and delta O-18 were log linear dependent on water vapor mixing ratio with respective R-2 of 17% and 14%, whereas d was significantly correlated with local RH and T, suggesting the less influence of air mass advection and more important contribution of the local source of moisture to atmospheric water vapor. Throughout the experiment, the local ET acted to increase delta D and delta O-18, with isofluxes of 102.5 and 23.50mmol m(-2) s(-1) parts per thousand, respectively. However, the dominated effect of entrainment still decreased delta D and delta O-18 by 10.1 and 2.24 parts per thousand, respectively. Both of the local ET and entrainment exerted a positive forcing on the diurnal variability in d.

关键词： stable isotopes atmospheric water vapor precipitation arid artificial oasis Heihe River Basin

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Global climate

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Bulletin of the American Meteorological Society 2020年第8期101卷 S9-S128页

作者： Dunn, R.J.H. Stanitski, D.M. Gobron, N. Willett, K.M. Met Office Hadley Centre Exeter United Kingdom NOAA/OAR Earth System Research Laboratories Boulder Colorado European Commission Joint Research Centre Ispra Italy Met Office Hadley Centre Exeter United Kingdom European Centre for Medium-Range Weather Forecasts Reading United Kingdom University of Maryland College Park Maryland Met Office Hadley Centre Exeter United Kingdom University of Reading Reading United Kingdom Department of Atmospheric and Planetary Science Hampton University Hampton Virginia NOAA/NESDIS National Centers for Environmental Information Asheville North Carolina University of Bremen Bremen Germany NOAA/OAR Earth System Research Laboratories Boulder Colorado Centro de Investigaciones sobre Desertificación - Spanish National Research Council Moncada (Valencia) Spain and Regional Climate Group Department of Earth Sciences University of Gothenburg Gothenburg Sweden Instituto de Geografía Pontificia Universidad Católica de Valparaíso Valparaíso Chile NOAA/OAR ESRL Global Monitoring Laboratory Boulder Colorado Department of Civil and Environmental Engineering Princeton University Princeton New Jersey Global Precipitation Climatology Centre Deutscher Wetterdienst Offenbach Germany University of Reading Reading United Kingdom European Centre for Medium-Range Weather Forecasts Reading United Kingdom National Oceanography Centre Southampton United Kingdom School of Engineering Newcastle University Newcastle-upon-Tyne United Kingdom Université de Paris Institut de physique du globe de Paris CNRS IGN Paris France and ENSG-Géomatique IGN Marne-la-Vallée France Global Modeling and Assimilation Office NASA Goddard Space Flight Center Greenbelt Maryland Sorbonne Université Paris France Universität Hamburg Hamburg Germany Department of Meteorology University of Reading Reading United Kingdom Geology Department University Centre in Svalbard Longyearbyen Norway Jet Propulsion Laboratory California Institute of Technology Wrightwood Calif

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Response of carbon dioxide emissions to warming under no-till and conventional till systems

Response of carbon dioxide emissions to warming under no-til...

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作者： Hou, Ruixing Ouyang, Zhu Wilson, G.V. Li, Yunsheng Li, Hanxia Key Lab. of Ecosystem Network Observation and Modeling Institute of Geographic Sciences Chinese Academy of Sciences Beijing 100101 China Yucheng Comprehensive Experiment Station China Academy of Science Beijing 100101 China USDA-ARS National Sedimentation Lab. Oxford MS 38655 United States

Differences in soil organic carbon (SOC) distribution, water holding capacity, and soil temperature between no-tillage (NT) and conventional tillage (CT) systems can result in different soil CO2 emissions which could affect global warming but few studies have addressed this concern. An open warming experiment was conducted in situ by infrared heating of longterm conservation tillage management plots in North China Plain (NCP) to determine the effects of warming on soil CO2 emissions and the correlation to changes in soil temperature and moisture. This experiment was conducted from February 2010 to June 2012 and included CT and NT plots with and without warming. Warming treatment increased soil temperature by 2.1 and 1.5°C, and decreased volumetric soil-water content by 14 and 10% for CT and NT systems, respectively. Soil CO2 emissions tended to decrease with time in CT while it consistently increased in NT system over the three wheat seasons and two maize seasons under warming. Our results suggest that differences in soil temperature and soil moisture between the two tillage systems could be enlarged with time by warming, and the potential exist for warming to promote more soil CO2 emission under NT relative to CT. There is a need to consider the differences in response to global warming between these two tillage systems to properly assess the benefits of NT to C sequestration. © Soil Science Society of America.

关键词： Soil temperature

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Nitrogen pollution and source identification of urban ecosystem surface water in Beijing

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Frontiers of Environmental Science & Engineering 2014年第1期8卷 106-116页

作者： Yufen REN Zhiwei XU Xinyu ZHANG Xiaoke WANG Xiaomin SUN D. J. BALLANTINE Shengzhong WANG State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China College of Urban and Environmental Science Northeast Normal University Changchtm 130024 China National Institute of Water and Atmospheric Research Hamilton 3216 New Zealand

Nitrogen contamination of surface water is a worldwide environmental problem with intensive agricul- ture and high population densities. We assessed the spatial and seasonal variation in concentrations of total nitrogen and different nitrogen species present in surface-water in Beijing, China. Also, chemical （NO3-N/C1-） and isotopic （615Nnitrate） indicators were used to identify nitrate sources. The results showed that, during 2009 and 2010, nitrate nitrogen concentrations ranged from 0.7 to 7.6 mg· L^-1, ammonium nitrogen from 0. I to 3.4 mg· L^-1, and total nitrogen from 2.4 to 17.0mg· L^-1. Inorganic nitrogen accounted for between 60 and 100% of total nitrogen at the ten monitoring sites. Nitrate nitrogen, ammonium nitrogen, and total nitrogen concentrations at the 2 downstream monitoring sites in south-eastern Beijing were significantly higher than those at the other eight upstream monitoring sites （P 〈 0.01）. Examination of seasonal variation showed that there was a significant inverse relationship between nitrate nitrogen concentrations and precipitation, and that nitrate nitrogen concentrations peaked in the dry seasons. The information given by the 15Nnitrate values and nitrate nitrogen concentrations, combined with the NO3-N/C1- ratio distribution, showed that domestic sewage was the major source of nitrate in Beijing. Methods to control and reduce sewage pollution are urgently needed to help manage surface water quality in Beijing.

关键词： nitrogen concentration spatial and seasonalvariation stable nitrogen isotope urban ecosystem source

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Soil Microbial Responses to Experimental Warming and Nitrogen Addition in a Temperate Steppe of Northern China

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Pedosphere 2014年第4期24卷 427-436页

作者： SHEN Rui-Chang XU Ming CHI Yong-Gang YU Shen WAN Shi-Qiang Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of Sciences University of Chinese Academy of Sciences Center for Remote Sensing and Spatial Analysis Department of EcologyEvolution and Natural ResourcesRutgers University14College Farm RoadNew Brunswick NJ 08901(USA) Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of Sciences Key Laboratory of Plant Stress Biology College of Life SciencesHenan University

The responses of soil microbes to global warming and nitrogen enrichment can profoundly affect terrestrial ecosystem functions and the ecosystem feedbacks to climate ***,the interactive effect of warming and nitrogen enrichment on soil microbial community is *** this study,individual and interactive effects of experimental warming and nitrogen addition on the soil microbial community were investigated in a long-term field experiment in a temperate steppe of northern *** field experiment started in 2006 and soils were sampled in 2010 and analyzed for phospholipid fatty acids to characterize the soil microbial *** soil chemical properties were also ***-year experimental warming significantly increased soil total microbial biomass and the proportion of Gram-negative bacteria in the ***-term nitrogen addition decreased soil microbial biomass at the 0-10 cm soil depth and the relative abundance of arbuscular mycorrhizal fungi in the *** interactive effect on soil microbes was detected when experimental warming and nitrogen addition were *** microbial biomass positively correlated with soil total C and N,but basically did not relate to the soil C/N ratio and *** results suggest that future global warming or nitrogen enrichment may significantly change the soil microbial communities in the temperate steppes in northern China.

关键词： arbuscular mycorrhizal fungi global warming Gram-negative bacteria nitrogen enrichment microbial biomass microbial community

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Diurnal variation of ozone flux over corn field in Northwestern Shandong Plain of China

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Science China Earth Sciences 2014年第2期57卷 503-511页

作者： ZHU ZhiLin SUN XiaoMin DONG YunShe ZHAO FengHua Franz X MEIXNER Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Department of Environmental Geography and Human Health Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences Biogeochemistry Department Max Planck Institute for Chemistry

High concentration ground-level ozone(O3)has adverse effects on plant growth and *** to the O3concentration-based index,the O3flux-based(especially stomatal O3uptake)index has been considered the better criterion for assessing the impact of ozone on vegetation and *** paper reports on a study of O3flux using the eddy covariance technique over a corn field in the Northwestern Shandong Plain of *** variation of atmospheric O3concentration,deposition velocity and flux,and their relationships to environmental factors are *** results show that:(1)During the observation period(9 August–28 September,2011),there was a strong diurnal variation of O3concentration,with low(16.5 nL L?1)and high(60.1 nL L?1)O3mean concentrations observed around 6:30 and 16:00,*** O3concentrations during daytime(6:00–18:00)and nighttime(18:00–6:00)were 39.8±23.1 and 20.7±14.1 nL L?1(mean±std),*** maximum observed concentration was 97.5 nL L?*** concentration was mainly affected by solar radiation and air temperature.(2)Whether daytime or nighttime,ground-level O3flux is always *** diurnal course of mean deposition velocity was divided into 4 phases:a low and stable process during nighttime,fast increasing in early morning,relatively large and steady changes around noon,and quickly decreasing in later *** and nighttime mean deposition velocities were 0.29 and 0.09 cm s?1,*** maximum deposition velocity was 0.81 cm s?*** magnitude of deposition velocity was influenced by the corn growth period,and its diurnal variation was significantly correlated with global radiation and relative humidity.(3)O3flux was affected by variations of both O3concentration and deposition velocity,with mean O3fluxes-317.7 and?70.2 ng m?2s?1during daytime and nighttime,*** was strong correlation between O3flux and CO2flux or latent heat *** comparing the deposition velocities of daytime a

关键词： ozone flux deposition velocity ozone concentration eddy covariance cropland ecosystem Northwestern Shandong Plain

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Impact of water diversion on the hydrogeochemical characterization of surface water and groundwater in the Yellow River Delta

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APPLIED GEOCHEMISTRY 2014年 48卷 83-92页

作者： Liu, Qiang Li, Fadong Zhang, Qiuying Li, Jing Zhang, Yan Tu, Chun Ouyang, Zhu Chinese Acad Sci Key Lab Ecosystem Network Observat & Modeling Inst Geog Sci & Nat Resources Res Beijing 100101 Peoples R China Chinese Acad Sci Ctr Agr Resources Res IGDB Shijiazhuang 050021 Peoples R China Chinese Acad Sci Grad Univ Beijing 100101 Peoples R China

The Yellow River Delta is undergoing severe ecosystem degradation through salinization caused mainly by seawater intrusion. The Yellow River diversion project, in operation since 2008, aims to mitigate a projected ecosystem disaster. We conducted field investigations across three ecosystems (Farmland, Wetland and Coast) in the delta to assess the effectiveness of the annual water pulse and determine the relationships between surface water and groundwater. The chemical characteristics of the groundwater in Farmland exclude the possibility of seawater intrusion. The Wetland is vulnerable to pollution by groundwater discharge from Farmland and to secondary salinization caused by rising water tables. The salinity values of groundwater at Coast sites likely reflect the presence of seawater trapped in the clay sediments, a premise corroborated through measurements of groundwater levels, stable isotopes and major ion signatures. Our delta D-delta O-18 two-dimensional graphic plot demonstrated that groundwaters of Farmland and Wetland changed toward more depleted isotopic compositions following water diversion, but this was not the case in the Coast sites, where the water table varied little year-round. A hydrochemical facies evolution diagram (HFE-D) demonstrated that freshening is taking place in the largest portions of the aquifers and that, without sustained water diversion recharge, these underground water bodies may switch from freshening to salinization on a seasonal time scale. Thus, the qualities of waters in coastal aquifers in the Yellow River Delta are substantially influenced by the process of ecological water diversion, and also by land use practices and by the lithological properties of the drainage landscape. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： WATER diversion WATER chemistry GROUNDWATER WATER salinization AQUIFERS

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Author Correction: Crowther et al. reply

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Nature 2018年第7716期560卷 E1页

作者： T W Crowther M B Machmuller J C Carey S D Allison J M Blair S D Bridgham A J Burton F A Dijkstra B Elberling M Estiarte K S Larsen H Laudon M Lupascu S Marhan J Mohan S Niu J J Peñuelas I K Schmidt P H Templer G Kröel-Dulay S Frey M A Bradford Institute of Integrative Biology ETH Zurich Universitätstrasse 16 8006 Zürich Switzerland. thomas.crowther11@***. Natural Resource Ecology Laboratory 1 499 Campus Delivery Colorado State University Fort Collins Colorado 80523-1499 USA. Division of Math and Science Babson College Massachusetts 02457 USA. Department of Earth System Science University of California Irvine Irvine California 92697 USA. Department of Ecology & Evolutionary Biology University of California Irvine Irvine California 92697 USA. Division of Biology Kansas State University Manhattan Kansas 66506 USA. Institute of Ecology & Evolution University of Oregon Eugene Oregon 97403 USA. School of Forest Resources & Environmental Science Michigan Technological University Houghton Michigan 49931 USA. Centre for Carbon Water & Food The University of Sydney Camden 2570 New South Wales Australia. Center for Permafrost (CENPERM) Department of Geosciences and Natural Resource Management University of Copenhagen Øster Voldgade 10 1350 Copenhagen K. Denmark. CSIC Global Ecology Unit CREAF-CSIC-UAB Cerdanyola del Vallès 08193 Catalonia Spain. CREAF Cerdanyola del Vallès 08193 Catalonia Spain. Department of Geosciences & Natural Resource Management University of Copenhagen Rolighedsvej 23 1958 Frederiksberg C Denmark. Department of Forest Ecology & Management Swedish University of Agricultural Sciences 90183 Umeå Sweden. Department of Geography National University of Singapore 1 Arts Link 117570 Singapore Singapore. Institute of Soil Science & Land Evaluation University of Hohenheim 70593 Stuttgart Germany. Odum School of Ecology University of Georgia Athens Georgia 30601 USA. Key Laboratory of Ecosystem Network Observation & Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China. Department of Biology Boston University Boston Massachusetts 02215 USA. Institute of Ecology & Botany MTA Centre for Ecolog

In this Brief Communications Arising Reply, the affiliation for author P. H. Templer was incorrectly listed as 'Department of Ecology & Evolutionary Biology, University of California Irvine, Irvine, California 92697, USA' instead of 'Department of Biology, Boston University, Boston, Massachusetts 02215, USA'. This has been corrected online.

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