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nitrogen cycling in the tropical rain forest of French Guiana:: comparison of two sites with contrasting soil types using δ¹⁵n

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JOURnAL OF TROPICAL ECOLOGY 1999年第1期15卷 1-22页

作者： Roggy, JC Prévost, MF Garbaye, J Domenach, AM INRA SILVOLAB Guyane Stn Rech Forestieres Kourou 97387 French Guiana

The natural n-15 abundance method for estimating symbiotic biological n-2-fixation was tested on legume trees from two rain forests on contrasting soils (oxisols and spodosols) in French Guiana. When possible, the significance of n-2-fixing species in the plant community was evaluated in terms of density, biomass and contribution of n-2-fixation to the building up of the total nitrogen mass in the leaves. Of the two sites, the rain forest on spodosols was the less favourable for application of the delta(15)n method: the available soil nitrogen was isotopically similar to fixed-n-2. Hence, the results showed that a reliable estimate of n-2- fixation could not be obtained. A substantial contribution of fixed-n-2 to the nitrogen nutrition of legumes was found on oxisols, with an average value of 54 % ndfa (nitrogen derived from the atmosphere). The contribution of the n-2-fixing legumes to the biomass of the stand was estimated to be 2 t ha(-1) for the leaf biomass and 136 t ha(-1) for the total above-ground plant biomass. With 7.5 % of trees in the stand able to fix n-2 (462 out of 6156), n-2-fixation was estimated to be 7 kg ha(-1) y(-1). These results are the first use of the delta(15)n method to estimate nitrogen input by n-2-fixing legumes to a natural rain forest. The inter-site variability observed in the delta(15)n of the non-fixing plants suggested different nitrogen-cycling processes in the two soils. The delta(15)n Of the non-n-2-fixing plants could be related to the soil nitrogen availability and be used as an indicator of efficient or non-efficient nitrogen-cycling rain forests. The spatial variability of the delta(15)n in the plant-available soil nitrogen pool and the nitrogen balance in tropical rain forests are discussed.

关键词： δ15n legumes ndfa n2-fixation nitrogen-cycling rain forest trees

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气相色谱-燃烧-同位素比值质谱法测定发酵液中尿素δ^13C和δ^15n

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质谱学报 2016年第1期37卷 60-67页

作者：李国辉钟其顶王道兵申世刚中国食品发酵工业研究院北京100015 全国食品发酵标准化中心北京100015 河北大学化学与环境科学学院河北省分析科学技术重点实验室河北保定071001

在酸性环境下,尿素与丙二醛-二甲基乙缩醛反应生成2-羟基嘧啶,随后由重氮甲烷甲基化形成2-甲氧基嘧啶。本研究以酵母发酵液为例,建立了气相色谱-燃烧-同位素比值质谱(GC-C-IRMS)法测定发酵液中尿素δ^(13)C和δ^(15)n,并对前处理方法和G... 详细信息

在酸性环境下,尿素与丙二醛-二甲基乙缩醛反应生成2-羟基嘧啶,随后由重氮甲烷甲基化形成2-甲氧基嘧啶。本研究以酵母发酵液为例,建立了气相色谱-燃烧-同位素比值质谱(GC-C-IRMS)法测定发酵液中尿素δ^(13)C和δ^(15)n,并对前处理方法和GC条件进行了优化。结果表明:尿素在不同13 C(0~5%)和15 n(0~10%)标记丰度下,标记量与GC-C-IRMS测定结果的相关性良好,线性相关系数R2分别为0.998和0.999,说明可在极低标记浓度下对尿素中δ^(13)C和δ^(15)n进行准确测定。采用该方法测定了酵母发酵液尿素中δ^(13)C和δ^(15)n,其重复性相对标准偏差分别为0.21‰和0.30‰,再现性相对标准偏差分别为0.23‰和0.29‰。该方法精度高、准确性好,可为低稳定同位素标记尿素示踪实验以及尿素循环代谢研究提供方法基础。

关键词：尿素衍生化气相色谱-燃烧-同位素比值质谱(GC-C-IRMS) δ13C δ15n

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Variation in the δ15n and δ13C composition of POM in the Lake Simcoe watershed

Variation in the δ15N and δ13C composition of POM in the L...

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作者： Kamila Anna Baranowska TRENT UNIVERSITY

学位级别：硕士

The purpose of this study was to quantify the variation of baseline carbon and nitrogen stable isotope signatures in the Lake Simcoe watershed and relate that variation to various physicochemical parameters. Particulate organic matter samples from2009 and2011 were used as representatives of baseline isotopic values. Temporal data from two offshore lake stations revealed thatδ 15 n of POM was lowest mid\summer and highest after the fall turnover. POMδ 13 C was variable throughout the summer before declining after fall turnover. Spatial data from the lake and the tributaries revealed that POM stable isotope signatures were highly variable. Various physicochemical parameters indicative of phytoplankton biomass were significantly positively correlated with POMδ 15 n and significantly negatively correlated with POM δ 13 C. The correlations were mostly significant in the tributaries, not the lake. Moreover, many of the correlations involvingδ 15 n of POM were driven by extreme values in Cook's Bay and its tributaries. In general, it's likely that different processes or combination of processes were affecting theδ 15 n andδ 13 C POM in the Lake Simcoe watershed as physicochemical parameters alone could not explain the variability. Measuring theδ 15 n of ammonium and nitrate, as well as theδ 13 C of DIC would help discern the dominant nitrogen and inorganic carbon cycling processes occurring in the Lake Simcoe watershed.

关键词： isotopic baseline δ15n δ13C stable isotopes particulate organic matter spatial variation

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Macrophytes as indicators of land-derived wastewater:: Application of a δ¹⁵n method in aquatic systems -: art. no. W01014

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WATER RESOURCES RESEARCH 2005年第1期41卷 1-9页

作者： Cole, ML Kroeger, KD McClelland, JW Valiela, I Boston Univ Marine Program Marine Biol Lab Woods Hole MA 02543 USA

[1] We measured delta(15)n signatures of macrophytes and particulate organic matter (POM) in six estuaries and three freshwater ponds of Massachusetts to assess whether the signatures could be used as indicators of the magnitude of land-derived nitrogen loads, concentration of dissolved inorganic nitrogen in the water column, and percentage of n loads contributed by wastewater disposal. The study focused specifically on sites on Cape Cod and nantucket Island, in the northeastern United States. There was no evidence of seasonal changes in delta(15)n values of macrophytes or POM. The delta(15)n values of macrophytes and POM increased as water column dissolved inorganic nitrogen concentrations increased. We found that delta(15)n of macrophytes, but not of POM, increased as n load increased. The delta(15)n values of macrophytes and groundwater nO3 tracked the percent of wastewater contribution linearly. This research confirms that delta(15)n values of macrophytes and nO3 can be excellent indicators of anthropogenic n in aquatic systems.

关键词： δ15n macrophyte stable isotope wastewater

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δ15n of Estuarine Fishes as a Quantitative Indicator of Watershed Urbanization

δ15N of Estuarine Fishes as a Quantitative Indicator of Wat...

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The 1st International Workshop on Urbanization in Watersheds: Ecological and Environmental Responses(第一届流域城镇化生态与环境响应国际研讨会)

作者： C.MORRIS Shing Yip (Joe) LEE J.van de MERWE Australian Rivers Institute and School of Environment Griffith University Gold Coast campusQld 4222Australia

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δ15n of Estuarine Fishes as a Quantitative Indicator of Watershed Urbanization

δ15N of Estuarine Fishes as a Quantitative Indicator of Wat...

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The 1st International Workshop on Urbanization in Watersheds:Ecological and Environmental Responses

作者： C.MORRIS Shing Yip (Joe) LEE J.van de MERWE Australian Rivers Institute and School of Environment Griffith University Gold Coast campus

Background and objectives: nitrogen stable isotope values(δ15n) have commonly been used as a qualitative indicator of catchment urbanization in estuaries, but no quantitative relationship has to date been established between δ15n and degree of urbanization. Methods: We sampled five species of common estuarine fish(Mugil cephalus, Acanthopagrus australis, Silago ciliata, Gerres subfasciatus and Herklotsichthys castelnaui) of different trophic levels from six estuaries in Southeast Queensland, Australia, to test if a quantitative relationship exists between δ15n and urbanization in the catchment. Degree of urbanization(Urban %) in the catchment adjacent to the tidal estuary was measured using polygons constructed in Google Earth images, and verified using data from the detailed Queensland Land Use Mapping Project(QLUMP). Findings: Significant linear relationships exist between fish δ15n and Urban % in most cases irrespective of the section of the estuary(upper, middle and lower) where the fish were caught, with no difference in slope and elevation between lines established for different sections. Inclusion of additional fish δ15n data from other Australian estuaries in a combined multiple regression model adding trophic level as a predictor generated a significant relationship predicting increase in δ15n values with increasing Urban % and trophic level. There is therefore a generic quantitative relationship between estuarine fish δ15n values and degree of urbanization applicable to different fish species, geographic location or feeding habit. Conclusion: While the generality of this relationship needs to be tested further in other geographic locations, our findings potentially improve the applicability of fish δ15n values as a quantitative indicator of urban influence in estuaries.

关键词： Estuaries Fish δ15n Urbanization Trophic Level Quantitative Indicator Google Earth

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鄱阳湖典型洲滩湿地植被叶片和土壤δ15n特征分析

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长江科学院院报 2020年第5期37卷 50-58页

作者：肖洋张翔王孟邓志民林玉茹长江水利委员会长江水资源保护科学研究所武汉430051 武汉大学水资源与水电工程科学国家重点实验室武汉430072 长江科学院水资源综合利用研究所武汉430010

为研究鄱阳湖典型洲滩湿地植被叶片和土壤δ15n特征,以蚌湖和修水之间的洲滩作为研究对象,选取典型断面研究2015年10-12月和2016年4月植被叶片和土壤δ15n的相关关系,探讨土壤含水量和无机氮(铵态氮和硝态氮)对植被叶片和土壤δ15n的影... 详细信息

为研究鄱阳湖典型洲滩湿地植被叶片和土壤δ15n特征,以蚌湖和修水之间的洲滩作为研究对象,选取典型断面研究2015年10-12月和2016年4月植被叶片和土壤δ15n的相关关系,探讨土壤含水量和无机氮(铵态氮和硝态氮)对植被叶片和土壤δ15n的影响。结果表明:大部分C3植被的叶片δ15n大于C4植被;湿润时期植被叶片和土壤δ15n大于干旱时期,但湿润时期和干旱时期植被叶片均较土壤富集15n。铵态氮在湿地土壤中占比高达87.43%,是土壤主要的无机氮,但湿地植被主要吸收硝态氮。研究区氮循环开度较小,土壤δ15n随着可利用氮素的增加而降低,而随着土壤含水量的增加而增加。植被叶片δ15n与土壤δ15n呈显著的正相关关系,植被叶片δ15n主要受土壤氮素变化和氮同位素分馏的影响。

关键词：洲滩湿地植被叶片 δ15n 氮循环氮素含量土壤含水量铵态氮硝态氮鄱阳湖

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施氏鲟不同组织中δ13C和δ15n值的变化规律

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水产学杂志 2019年第6期32卷 23-28页

作者：李雷王念民都煜李娜马波中国水产科学研究院黑龙江水产研究所农业农村部黑龙江流域渔业资源与环境重点野外科学观测试验站黑龙江哈尔滨150070

2015年春季向当地渔民收购黑龙江中游抚远江段体质量范围为(40.9~3500.8)g的施氏鲟Acipenser schrenckii样本17尾,测定背部肌肉、骨板、鳃和肝等组织的δ13C和δ15n,利用单因素方差分析对比4种组织的δ13C和δ15n平均值和δ13C以及δ15... 详细信息

2015年春季向当地渔民收购黑龙江中游抚远江段体质量范围为(40.9~3500.8)g的施氏鲟Acipenser schrenckii样本17尾,测定背部肌肉、骨板、鳃和肝等组织的δ13C和δ15n,利用单因素方差分析对比4种组织的δ13C和δ15n平均值和δ13C以及δ15n的两两之间的关系。结果表明:(1)施氏鲟四种组织的δ13C以及δ15n平均值均存在显著性差异(P<0.01);(2)施氏鲟4种组织两两之间的δ13C具有显著的线性关系,背部肌肉、骨板和鳃等3种组织两两之间的δ15n具有显著的线性关系。本文首次研究了δ13C和δ15n在施氏鲟不同组织中的变化规律,可为利用碳氮稳定同位素技术研究施氏鲟食物来源及营养级位置的取样提供参考。

关键词：稳定同位素施氏鲟 δ13C δ15n

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基于环境因子的全球主要陆地土壤δ15n分布图绘制

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环境监测管理与技术 2024年第6期36卷 48-53页

作者：单阳王霞昝麒麟赖晓明姜晟范清华李娣李旭文江苏省环境监测中心江苏南京 210041 中国科学院南京地理与湖泊研究所江苏南京 210008

基于全球812个样点的土壤δ15n与气象、土壤、地形和植被等环境因子数据集,通过随机森林回归算法构建土壤δ15n与环境因子关系的总集和分集模型,对比精度识别最优模型.根据最优模型和环境因子数据,绘制空间分辨率为0.25°的全球主... 详细信息

基于全球812个样点的土壤δ15n与气象、土壤、地形和植被等环境因子数据集,通过随机森林回归算法构建土壤δ15n与环境因子关系的总集和分集模型,对比精度识别最优模型.根据最优模型和环境因子数据,绘制空间分辨率为0.25°的全球主要陆地自然生态系统土壤δ15n空间分布图.结果表明:总集模型精度为RMSE=1.63‰,R2=0.61;基于归一化植被指数(nDVI)分类的分集模型精度最高,为最优模型,平均精度为RMSE=1.19％c,R2=0.69;全球主要陆地自然生态系统土壤δ15n平均值为4.88‰,变化范围为-0.49‰～12.29‰,标准差为1.74‰.

关键词： δ15n 氮循环环境因子随机森林回归土壤

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Using nitrate dual isotopic composition (δ¹⁵n and δ¹⁸O) as a tool for exploring sources and cycling of nitrate in an estuarine system: Elkhorn Slough, California

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JOURnAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIEnCES 2009年第G1期114卷

作者： Wankel, Scott D. Kendall, Carol Paytan, Adina Harvard Univ Dept Organism & Evolut Biol Cambridge MA 02138 USA US Geol Survey Menlo Pk CA 94025 USA Univ Calif Santa Cruz Inst Marine Sci Santa Cruz CA 95064 USA

nitrate (nO3-) concentrations and dual isotopic composition (delta n-15 and delta O-18) were measured during various seasons and tidal conditions in Elkhorn Slough to evaluate mixing of sources of nO3- within this California estuary. We found the isotopic composition of nO3- was influenced most heavily by mixing of two primary sources with unique isotopic signatures, a marine (Monterey Bay) and terrestrial agricultural runoff source (Old Salinas River). However, our attempt to use a simple two end-member mixing model to calculate the relative contribution of these two nO3- sources to the Slough was complicated by periods of nonconservative behavior and/or the presence of additional sources, particularly during the dry season when nO3- concentrations were low. Although multiple linear regression generally yielded good fits to the observed data, deviations from conservative mixing were still evident. After consideration of potential alternative sources, we concluded that deviations from two end-member mixing were most likely derived from interactions with marsh sediments in regions of the Slough where high rates of nO3- uptake and nitrification result in nO3- with low delta n-15 and high delta O-18 values. A simple steady state dual isotope model is used to illustrate the impact of cycling processes in an estuarine setting which may play a primary role in controlling nO3- isotopic composition when and where cycling rates and water residence times are high. This work expands our understanding of nitrogen and oxygen isotopes as biogeochemical tools for investigating nO3- sources and cycling in estuaries, emphasizing the role that cycling processes may play in altering isotopic composition.

关键词： δ15n δ18O estuary nitrification denitrification

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