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Nitrogen isotopic composition of plant-soil in the loess Plateau and its responding to environmental change

chinese Science Bulletin 2009年第2期54卷 272-279页

作者： liu weiguo1,2 & wang zheng1,3.1 state key laboratory of loess and quaternary geology,{3., chinese academy of sciences, xi’an 710075, China 2 xi’an Jiaotong University, School of Human Settlement and Civil Engineering, xi’an 710049, China 3.Graduate University of chinese academy of sciences, Beijing 100049, China state key laboratory of {3. and {3. geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China School of Human Settlement and Civil Engineering Xi’an Jiaotong University Xi’an China Graduate University of chinese academy of sciences Beijing China

The nitrogen isotope of soil is of emerging significance as an indicator of climatic change and biogeochemical cycle of nitrogen in nature systems. In this paper, the nitrogen content and isotopic composition of modern ecosystems from arid and semiarid loess Plateau in northwestern China, including plant roots and surface soil, were determined to investigate trends in δ15N variation of plant roots and soil along a precipitation and temperature gradient in northwestern China under the East Asian Monsoon climate condition. The δ15N values of surface soil from the study area vary from ?1.2‰ to 5.8‰, but from -5.1‰ to 1.9‰ in the plant roots. Our results indicate that (1) although the isotopic compositions of both plant roots and surface soil change with a similar trend along the climate gradient, the apparent nitrogen difference between plant roots and soil existed, with -δ15N values ranging from 0.3. to 7.2‰ with average of 4.1‰; and (2) mean annual precipitation (MAP) is the dominant factor for isotopic composition of plant-soil nitrogen in the loess Plateau, and the δ15N values are less correlated with MAT; we suggest that nitrogen isotopic composition of soil is a potential tracer for {3.al changes.

关键词：氮同位素物理性质化学性质环境论

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Boron isotopic fractionation in laboratory inorganic carbonate precipitation:Evidence for the incorpora-tion of B(OH)_3.into carbonate

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Science China earth sciences 2008年第12期51卷 1776-1785页

作者： xiAO YingKai1,2, LI HuaLing1,3. liu weiguo4, {3. xiuFang1 & JIANG ShaoYong5 1 Qinghai institute of Salt Lakes,{3., xining 810008, China 2 state key laboratory of environmental Geochemistry, institute of Geochemistry,{3., Guiyang 550002, China 3.Nanjing institute of geology and Mineral Resources, Nanjing 210016, China 4 state key laboratory of loess and quaternary geology, institute of earth environment,{3., xi’an 710075, China 5 state key laboratory for Mineral Deposits Research, Department of earth sciences, Nanjing University, Nanjing 210093. China Qinghai institute of Salt Lakes Chinese Academy of Sciences Xining China state key laboratory of {3.al Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang China Nanjing institute of geology and Mineral Resources Nanjing China state key laboratory of {3. and {3. geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China state key laboratory for Mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing China

A laboratory inorganic carbonate precipitation experiment at high pH of 8.96 to 9.3. was conducted, and the boron isotopic fractionations of the precipitated carbonate were measured. The data show that boron isotopic fractionation factors (αcarb-3. between carbonate and B(OH)3.in seawater range 0.93. and 0.965, with an average value of 0.953. Our results together with those reported by Sanyal and collabo-rators show that the αcarb-3.values between carbonate and B(OH)3.in solution are not constant but are negatively correlated with the pH of seawater. The measured boron isotopic compositions of carbonate precipitation (δ11Bcarb) do not exactly lie on the best-fit theoretical δ 11B4-pH curves and neither do they exactly parallel any theoretical δ 11B4-pH curves. Therefore, it is reasonable to argue that a changeable proportion of B(OH)3.with pH of seawater should also be incorporated into carbonate except for the dominant incorporation of B(OH)4- in carbonate . Hence, in the reconstruction of the paleo-pH of sea-water from boron isotopes in marine biogenic carbonates, the use of theoretical boron isotopic frac-tionation factor (α4-3. between B(OH)4- and B(OH)3.is not suitable. Instead, an empirical equation should be established.

关键词： boron isotopic fractionation biogenic carbonate B(OH)3 incorporation

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Interpreting Larix principis-rupprechtii radial growth in northern China based on the Vaganov-Shashkin model

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Journal of Forestry Research 2024年第3期35卷 99-110页

作者： Jiachuan wang Shuheng Li Qiang Li Yili Guo Yijie Han Qi liu Yiqi Zhao College of Urban and environmental sciences Northwest UniversityXi'an 710127People's Republic of China institute of Global environmental Change Xi'an Jiaotong UniversityXi'an 710049People's Republic of China Shaanxi key laboratory of {3. Surface System and environmental Carrying Capacity Northwest UniversityXi'an 710127People's Republic of China state key laboratory of {3. and {3. geology Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710061People's Republic of China

Changes in annual radial growth is an important indication of climate change. Dendroclimatology studies in northern China have focused on linear statistical analysis,but lacking studies based on the process of ring formation to clarify the radial growth of trees. Tree-ring width standard chronology(STD) was established using samples of Larix principis-rupprechtii collected at 23.3.m altitude on Luya Mountain. Using the Vaganov-Shashkin(VS) model to simulate growth and development, the internal physiological mechanism of radial growth is identified. It was concluded that:(1) the growing season of L. principis-rupprechtii was May to September;(2) soil moisture was a significant factor in the early and late growing seasons, and temperature was the dominant factor in its main growth period;and(3. formation of narrow ring widths was closely related to drought stress, the development of wide ring widths will be restricted by increasing future temperatures. The VS model is applicable for radial growth simulation of subalpine coniferous forests and for guiding the cultivation of local tree species in the future.

关键词： Vaganov-Shashkin model Larix principis-rupprechti Tree-ring width Annual growth

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Carbon isotope and environmental changes in lakes in arid Northwest China

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Science China earth sciences 2019年第8期62卷 1193-1206页

作者： weiguo liu xiangzhong LI {3. wang Huangye wang Hu liu Bo ZHANG Huan ZHANG institute of earth environment CASState Key Laboratory of Loess and Quaternary GeologyXi’an 710061China University of chinese academy of sciences Beijing 100049China

The stable carbon isotope composition(δ13.C) of lacustrine sediments, which can record changes in past environmental conditions such as the C4/C3.terrestrial vegetation composition, has been widely used for the reconstruction of terrestrial ecosystems and global climate changes. It has also been widely used in paleolimnological studies in arid northwestern China. In recent years, however, an increasing number of studies have enriched the environmental significance reflected by the stable carbon isotope geochemistry of lakes;therefore, the interpretation of lake δ13.C variations in paleoenvironmental reconstructions should be carefully evaluated from various aspects. In this paper, previous studies from the past several decades on the lacustrineδ13.C variations in arid northwestern China were reviewed, and the possible mechanisms of the δ13.C variations were *** study will provide a reference for the application of carbon isotope geochemistry in paleoenvironmental reconstructions.

关键词： Carbon isotope Lake Arid region of northwestern China Total organic carbon Organic biomarkers

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Variations in nitrogen isotopic values among various particle-sized fractions in modern soil in northwestern China

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chinese Journal Of Geochemistry 2011年第3期30卷 295-303页

作者： liu weiguo wang Zhoufeng wang {3. FENG xiahong ZHANG Pu state key laboratory of {3. and {3. geology lEE CAS Xi'an 710075 China School of Human Settlement and Civil Engineering Xi'an Jiaotong University Xi 'an 710049 China School of environmental Science and Engineering Chang 'an University Xi'an 710054 China Department of earth sciences Dartmouth College Hanover NH 03755 USA

Ratios of stable nitrogen isotopes in organic matter derived from plants and preserved in soil are potential tracers for nitrogen cycles in natural ecosystems and valuable for evaluation of climate change. However, the rela-tionship between nitrogen isotopic compositions in surface soil and in plant litter during the decomposition process from plant litter to soil organic matter is not well understood. By using nitrogen isotopic analysis of soil parti-cle-sized fractions, nitrogen isotope discrimination between plant litter and surface soil organic matter in various modern ecosystems in northwestern China was conducted. The results of our study indicate that: (1) in general, the nitrogen isotopic compositions of particle-sized fractions from surface soil are different, and δ15N values increase from plant litter to fine soil organic matter; (2) the δ15N values in the soil particle-sized fractions become larger with increasing relative humidity and temperature, and the largest variation in the δ15N values is from -5.9‰ to -0.3.; and (3. under a controlled climate, significant nitrogen isotope differences in δ15N values (Δδ15Nplant-soil) between plant litter and bulk soil organic matter were observed, with the values of 1.52 to 4.75 at various sites. Our results suggested that comparisons of Δδ15N values between bulk soil and the particle-sized fractions of soil could reveal the effect of humidity on transferring process of nitrogen from plant to soil in arid and semi-arid ecosystems.

关键词：稳定氮同位素中国西北地区现代土壤粒子大小自然生态系统土壤有机质颗粒大小组分

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支链GDGTs与黄土古温度重建:机遇与挑战

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第四纪研究 2024年第5期44卷 1296-1307页

作者：卢红选王欢业刘旭盛维娟刘卫国中国科学院地球环境研究所黄土与第四纪地质国家重点实验室陕西西安710061 西安地球环境创新研究院陕西西安710061

目前对全球古温度的理解主要基于海洋记录,由于缺乏可靠的陆地古温度指标,对陆地温度变化的认识较为有限,这限制了对全球变暖背景下,陆地温度变化规律和机制的深入理解。支链甘油二烷基甘油四醚类化合物(brGDGTs)是某些细菌微生物细胞... 详细信息

目前对全球古温度的理解主要基于海洋记录,由于缺乏可靠的陆地古温度指标,对陆地温度变化的认识较为有限,这限制了对全球变暖背景下,陆地温度变化规律和机制的深入理解。支链甘油二烷基甘油四醚类化合物(brGDGTs)是某些细菌微生物细胞脂膜中的四醚化合物,近20年来已成为广泛关注的陆地古温度计。该温度计一经推出,便在黄土古温度,特别是长时间尺度的古温度重建中发挥了重要作用。本研究首先回顾了brGDGTs温度计的发展历史,总结了近年来该温度计在细菌培养实验、现代过程调研、仪器分析方法、数据处理技术等方面的创新和进展。然后介绍了支链GDGTs在黄土古土壤剖面中不同时间尺度的古温度重建研究进展。黄土高原brGDGTs记录的陆地温度呈现明显的冰期-间冰期波动特征,表明太阳辐射和全球冰量对陆地温度变化重要的驱动作用;但与海洋温度相比,冰盛期-冰消期时段增温超前于海洋记录,推测陆地下垫面(植被、土壤湿度等)动态演化可能会对陆地温度变化起着重要的调控作用。最后多角度分析了brGDGTs陆地古温度重建面临的机遇和挑战。作为稀缺的陆地古温度计,brGDGTs为认识陆地温度变化规律和机制提供了难得的工具,但其确切生物来源、形成机制尚不明确。另外,全球黄土brGDGTs温度在变化趋势、周期和幅度上存在较大差异,且造成这种差异的原因还不清楚。为了应对这些挑战,应继续加强brGDGTs温度计的基础理论研究,明确其来源和形成机制,优化分析方法和校正模型。同时,结合现代观测和模拟研究,探究不同时间尺度下陆地下垫面(植被、土壤湿度等)与温度变化之间的反馈机制,进一步丰富我们对全球温度变化规律和机制的认识。

关键词： brGDGTs 古温度黄土气候指标

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Branched tetraether lipids in chinese soils:Evaluating the fidelity of MBT/CBT proxies as paleoenvironmental proxies

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Science China earth sciences 2016年第7期59卷 1353-1367页

作者： zheng FengFeng ZHANG ChuanLun CHEN YuFei LI FuYan MA CenLing PU Yang ZHU YuanQing wang YongLi liu {3. state key laboratory of Marine {3. Tongji UniversityShanghai 200092China School of Geography and Remote Sensing Nanjing University of lnformation Science&TechnologyNanjing 210044China earthquake Administration of Shanghai Municipality Shanghai 200062China key laboratory of Gas Geochemistry Institute of Geology and GeophysicsChinese Academy of SciencesLanzhou 730000China state key laboratory of {3. and {3. geology Institute of Earth EnvironmentChinese Academy of SciencesXi'an 710075China

The ubiquitous occurrence of branched glycerol dialkyl glycerol tetraethers(br GDGTs) in soils has allowed development of new proxies for reconstruction of past climate and environment. The methylation and cyclization degrees of br GDGTs, expressed as MBT and CBT, respectively, are reported to be mainly controlled by mean annual air temperature(MAAT) and soil p H. However, the br GDGT-derived temperatures and soil p H scatter widely when data from different environmental conditions are considered. In this study, we collected over 3.0 soil samples from China, which are representative of humid(xishuangbanna, Guangzhou, and Shanghai), semi-arid(Dongying) and semi-arid/arid(Lanzhou, Tibetan Plateau) regions. Collectively we have the most extensive dataset that broadly characterizes the distribution of br GDGTs according to climate zones in China. The overall data demonstrate that the MBT/CBT derived temperatures better match the measured MAATs in humid and non-alkaline regions than those from regions of low MAP(7.0–7.5). Similarly, CBT describes soil p H much better in humid and non-alkaline soils than in semi-arid/arid and alkaline soils; the semi-arid/arid and alkaline soils tend to show a positive correlation between soil p H and CBT, which contradicts that in the humid and non-alkaline soils. While soil p H, MAAT and mean annual precipitation(MAP) are dominating factors controlling the br GDGT distribution across all climate zones, conductivity, total organic carbon and total nitrogen, as well as soil water content can also play an important role locally. Removing br GDGT-II resulted in a revised CBT index that provides more accurate estimation of p H, especially in semi-arid/arid and alkaline soils. The overall chinese dataset demonstrates that continental air temperature derived from br GDGT-proxies can vastly deviate from real measurements and should be used with extreme caution in paleo-climate or-environment studies.

关键词： brGDGTs MAAT Soil pH MAP chinese soils Tibetan Plateau chinese loess Plateau

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High-Resolution Geochemical Records in the Inner Shelf Mud Wedge of the East China Sea and Their Indication to the Holocene Monsoon Climatic Changes and Events

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Journal of Ocean University of China 2021年第6期20卷 1409-1418页

作者： wang Longsheng ZHOU Bin zheng Bang wang Ke MEI {3. wang Qing wang {3.aohui zheng Hongbo Coast institute of Ludong University Yantai 264025China School of earth sciences and Engineering Nanjing UniversityNanjing 210023China key laboratory of Coastal environmental Processes and Ecological Remediation Yantai Institute of Coastal Zone Research(YIC)Chinese Academy of Sciences(CAS)Yantai 264003China Department of earth and Planetary Science Graduate School of ScienceThe University of TokyoTokyo 1130033Japan key laboratory of Gas Hydrate Ministry of Natural ResourcesQingdao Institute of Marine GeologyQingdao 266071China Research Center for earth System Science Yunnan UniversityKunming 650091China state key laboratory of {3. and {3. geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China

The inner shelf mud wedge(ISMW)located in the East China Sea(ECS)is the fine-grained sedimentary area with high sedimentation rate and has provided an ideal study area for understanding the East Asian Summer Monsoon(EASM)evolution during the *** this paper,we presented the high-resolution geochemical data of the sediments from the core MD06-3.40 in the ISMW of the ECS determined by X-ray fluorescence core scanning(XRF-CS)analysis,a high-resolution,continuous,and multielement *** and factor analysis results reveal that the variations of elemental compositions(Al,Si,K,Ti,Fe),the elemental ratios of Al/Zr,Ca/Ti and Rb/Sr,and the factor scores(F1 are correlated with the changes of the EASM during the period of 6000–13.0 cal yr *** higher values of geochemical compositions indicating the terrigenous inputs implied the intensification of anthropogenic activities after 13.0 cal yr ***,the significant decrease of most geochemical compositions and the F1 factor scores during 4500–3.00 cal yr BP and 1700–1500 cal yr BP,within the dating errors,coincided with the weak EASM events(presumably drought and cold events).The spectral analysis results of K concentrations,Al/Zr ratios and F1 factor scores show the millennial and centennial climatic fluctuations,which are consistent with other marine sedimentary records in the adjacent *** the findings show that the geochemical compositions of sediments from core MD06-3.40 are influenced by the EASM evolution,the variable El Niño/Southern Oscillation(ENSO)and the local oceanic thermohaline circulation(e.g.,Kuroshio Current).These results are greatly helpful in uncovering the forcing mechanism of the monsoonal climate in the east China over the Holocene and also contribute to the understanding of EASM variability.

关键词： Holocene climatic event East Asian Summer Monsoon XRF core scanning inner shelf mud wedge

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Calibration of the U3.K index of long-chain alkenones with the in-situ water temperature in Lake Qinghai in the Tibetan Plateau

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Science China(Technological sciences) 2013年第3期56卷 803-808页

作者： wang zheng liu {3. state key laboratory of {3. and {3. geology Institute of Earth EnvironmentChinese Academy of Sciences School of Human Settlement and Civil Engineering Xi'an Jiaotong University

Long-chain alkenones (LCAs) can potentially be used as indicators to understand past variations in lacustrine *** research has suggested that the relationship between the temperature and the unsaturation index of LCAs should be calibrated individually,because of the possible variations in the alkenone-producing algal species in the lacustrine *** this work,we have calibrated U3.K' of water filter samples against the in-situ water temperature in Lake Qinghai,Tibetan *** are significant relationships between U3.K' and the water temperature,a non-linear relationship was *** the U3.K' values did not respond sensitively at lower temperatures,we suggested that a quadratic regression (U3.K' =0.0011×T2-0.0201×T+0.1959,n=15,r2=0.74) was appropriate than linear regression to represent the relationship between the in-situ temperatures and U3.K'.Meanwhile,the U3.K correlation relationship was not more significant than U3.K' index in our *** of the C3.:4 effects by salinity change,we suggest U3.K is not as robust as the U3.K' index as a temperature proxy,at least for the salt lake in the Tibetan *** calibration of the U3.K' index in this work has provided a new understanding of historic climatic changes in the Tibetan Plateau.

关键词： U3.K index in-situ temperature Lake Qinghai

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鄂尔多斯活动地块边界带15000年以来强震活动与现今大地震空区

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科学通报 2024年第18期69卷 2632-2647页

作者：郑文俊彭慧刘兴旺张竹琪张冬丽魏拾其王旭龙中山大学地球科学与工程学院广东省地球动力作用与地质灾害重点实验室珠海519080 南方海洋科学与工程广东省实验室(珠海) 珠海519080 甘肃省地震局甘肃兰州地球物理国家野外科学观测研究站兰州730000 中国地震局地质研究所地震动力学国家重点实验室北京100029 中国科学院地球环境研究所黄土与第四纪地质国家重点实验室西安710061

在青藏高原和太平洋构造域的共同作用下,鄂尔多斯活动地块及周缘边界带的断裂构造存在明显的运动性质差异,形成了明确的分区分段特征.本文基于探槽古地震记录和历史地震资料,通过多探槽中揭露的多类证据综合限定各断裂带上的强震事件,... 详细信息

在青藏高原和太平洋构造域的共同作用下,鄂尔多斯活动地块及周缘边界带的断裂构造存在明显的运动性质差异,形成了明确的分区分段特征.本文基于探槽古地震记录和历史地震资料,通过多探槽中揭露的多类证据综合限定各断裂带上的强震事件,获得了鄂尔多斯活动地块周缘边界带主要断裂带上15000年以来180次强震事件,重建了地块边界带不同构造区强震活动的时间序列,将千年尺度的地震记录延长到万年尺度.在此基础上,建立了鄂尔多斯活动地块各不同构造区近15000年以来强震活动时空分布图像.鄂尔多斯活动地块各边界带长时间尺度的强震活动特征显示:地块边界带各分区内存在差异性的活动期和平静期,北、东北、东、西边界均存在不同程度的地震丛集和迁移规律;围绕鄂尔多斯活动地块周缘的边界带内15000年以来强震分布具有较为明显的丛集发生特征,平静期持续时间(约200~500年)不等;近5000年以来,各边界带上强震活动频次有明显增强的趋势,部分区段存在未来发生强震的风险;综合近3.00年以来历史地震、最新强震破裂图像等判定鄂尔多斯活动地块边界带仍存在7个明显的大地震空区,即强震危险区.

关键词：鄂尔多斯活动地块边界带强震活动大地震空区

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