海洋有机质的光谱分析方法评述

海洋有机质的光谱分析已成为海洋碳循环的研究热点之一。本文从天然有机质吸收光谱和荧光光谱分析的基本原理入手,系统梳理了有机质光谱分析中容易被忽视的基本概念,讨论了过滤与保存方式、p H值、荧光内滤效应等对有机质光谱分析的影响。结合色氨酸、酪氨酸、腐殖酸及大量现场样品的实验结果,对吸收光谱和三维荧光光谱的不同解析方法进行了系统的分析与对比。基于在南海、西菲律宾海获取的现场调查数据,对于文献中常用的荧光指数(FI)、腐殖化指数(HIX)、自生源指数(BIX)等光谱参数的内在含义及其在海洋环境中的适用性进行了评述。此外,还归纳和总结了胶体有机质和颗粒有机质荧光分析的最新进展,并对今后在光谱分析与观测领域有待完善和突破的一些关键领域进行了展望。国家自然科学基金面上项目(41876083;41276064);;“科学”号高端用户项目(KEXUE2017G11;KEXUE2018G03);;厦门市海洋与渔业局项

Impacts of storm event on DOM composition and flux in two Jiulong Tributaries with different watershed features

通过调查2014年7月"麦德姆"台风影响期间福建九龙江北溪(流域以林地为主)和西溪(农业流域和城市背景)下游定点站DOM的时间序列,测定样品的DOC含量及其吸收光谱和三维荧光光谱,以评估不同流域背景对河流DOM动力学降雨响应的差异性,并为流域-河口系统的一体化管理提供重要参考。降雨期间,两条河流DOC浓度、吸收系数aCDOM(350)以及总荧光强度均随径流量升高而增大,并在水位下降期持续增加,且西溪增加量明显高于北溪,说明受人类活动扰动大的流域河流有机质对暴雨事件的响应更为灵敏;北溪和西溪的SUVA254分别显示出增大和减小的相反变化趋势,表明林地背景的流域主要冲刷芳香度高的DOM到河流,农业和城市背景则相反;降雨期西溪对九龙江DOM入海通量的贡献率高于北溪,与基流期北溪贡献率占主导恰巧相反,这种碳通量的逆转表明暴雨事件会放大人类活动对下游河口生态环境的影响。Watershed features have great impacts on river DOM composition and flux. In this study, temporal variations in DOM of the North(dominated by forestland)and West(dominated by farmland and urban area)Jiulong River were investigated during the typhoon"Matmo"in July, 2014. The DOM was characterized by DOC, absorption spectroscopy, and fluorescence excitation emission matrix spectroscopy(EEMs)analysis. The DOC concentration, absorption coefficient aCDO(350)and total DOM fluorescence intensity of both rivers increased significantly in both rising and falling hydrograph during the storm event. However, DOM abundance in the West River showed a much greater increase than that in the North River, suggesting more sensitivity of river DOM to rainstorm events in the watershed with greater anthropogenic perturbation. The specific absorption coefficient(SUVA254)of CDOM showed different variation tends between the North and West River,indicating that river DOM in forest-dominant watershed had high aromaticity and average molecular weight. The West River showed higher fluxes of DOM than the North River during storm event, which was opposite to that under the base flow condition. This reversion in DOM export flux suggested that storm event could amplify the influence of human activities in the watershed on the receiving estuarine ecosystems.The present findings are of great significance for the integrated management of coupled river-estuary system.国家自然科学基金项目(41276064,U1305231

1978～2008年中国湿地类型变化

分别基于美国陆地卫星(Landsat MSS/TM/ETM+)和中巴资源卫星(CBERS-02B)影像数据,以人工目视解译为主,完成了中国1978～2008年4期(基准年分别为1978,1990,2000和2008年)湿地遥感制图,并进行了大量的室内外验证.在此基础上,对我国湿地现状及近30年来湿地变化进行了初步分析,得到以下主要结论:(ⅰ)截止2008年,中国湿地面积约为324097km2,其中以内陆沼泽(35%)和湖泊湿地(26%)为主.(ⅱ)1978～2008年,中国湿地面积减少了约33%,而人工湿地增加了约122%.过去30年里湿地减少的速度大幅降低,由最初5523km2/a(1978～1990年)降为831km2/a(2000～2008年).(ⅲ)减少的自然湿地(包括滨海湿地和内陆湿地),其类型变化由湿地向非湿地转化的比例逐渐降低.初期(1978～1990年)几乎全部(98%)转换为非湿地;在1990～2000年间减少的自然湿地约有86%转化为非湿地,而在2000～2008年,这一比例下降为77%.(ⅳ)气候变化和农业活动是中国湿地变化的主要驱动因素,湿地变化在中国分为三大不同特征区域,即西部三省/自治区(西藏、新疆和青海)、北部两省/自治区(黑龙江和内蒙古)和其他省市区.其中西部区域尤其是青藏高原,湿地变化的驱动因子以气候增温为主;新疆湿地由于气候增温和农业活动共同作用造成变化不大.北部省/自治区的湿地变化则主要由农业活动引起;而其他省市区的湿地变化几乎完全受控于人类的农业经济活动

Characterization of Dissolved Organic Matter in Groundwater from the Coastal Dagu River Watershed,China Using Fluorescence Excitation-Emission Matrix Spectroscopy

利用三维荧光光谱研究了大沽河流域地下水中溶解有机物(dOM)的荧光组分类型及其空间分布与变化,并与地表河水进行了比较。基于平行因子分析模型在大沽河流域识别出2个类腐殖质组分及1个类蛋白质组分。研究区域上、下游地下水中各荧光组分的强度低,但中游区域呈现高值区,与人为污染的下渗输入以及为阻止海水入侵而修建的截渗墙对地下水循环模式的改变有关。地下水dOM以类腐殖质组分为主,类蛋白质组分平均只占15%,不及地表河水的一半,其新鲜度指数(β/α)也低于河水但荧光指数(fI)、腐殖化指数(HIX)高于河水,表明地下水dOM的腐殖化程度更高,与地下水停留时间长、微生物降解作用的贡献更为显著有关。本研究揭示,三维荧光指纹技术可区分天然背景及人为活动对地下水中dOM含量及性质的影响,是研究地下水环境中的碳循环过程及其影响因素的有用工具。The fluorescent properties of dissolved organic matter(DOM) from groundwater in the coastal Dagu River watershed,North China were determined using excitation-emission matrix spectroscopy(EEMs) analysis.Surface water DOM samples were also investigated for comparison.Two humic-like components(C1 : 250,355/472nm;C2 : <240,325 / 400nm) and one protein-like component(C3: <240,280/340nm) were identified using parallel factor analysis.Low intensities for all components were observed in groundwater DOM from the upper and lower reaches of the study area.However,higher abundances of these components occurred in the middle reaches,reflecting the combined effect of seepage of surface water with strong anthropogenic pollution and the alteration of groundwater circulation due to cutoff as a result of the construction of a cutoff wall since the late 1990s.The humic-like components were dominant in groundwater DOM,with the average percentage of the protein-like component being only 15%,which was less than half of the corresponding percentage in surface water DOM.The freshness index in groundwater DOM was lower than the surface water samples,while the fluorescence index and humification index were higher than in the latter.These indices demonstrated the much higher degree of humification for groundwater DOM,which may be related to the longer residence time of groundwater and greater contribution of microbial degradation in the aquifer environment.This study demonstrated that EEMs could distinguish between the effects of natural background and human activities on the quantity and characteristics of the groundwater DOM,and thus could be a useful tool for studing the carbon dynamics and the controlling factors in groundwater systems.TheNationalNaturalScienceFoundationofChina(41072174;41276064and40776041

INFLUENCE OF TYPHOON AND RAINSTORM PROCESS ON DISSOLVED INORGANIC NITROGEN AND DISSOLVED INORGANIC PHOSPHORUS OF SEA WATER IN XIAMEN BAY

于1998年10号台风、2000年10号台风碧利斯和2000年6月厦门地区特大暴雨影响期间,在厦门港湾对表层海水溶解无机氮(DIN)、溶解无机磷(DIP)以及盐度、DO、Chl a等相关环境因子进行定点连续观测。描述了台风暴雨期间和恢复期DIN、DIP的变化特征。对水动力因素、底质再悬浮、有机物氧化降解及生物活动等因素的影响进行了初步的探讨。Dissolved inorganic nitrogen (DIN) , dissolved inorganic phosphorus (DIP) of surface water and other related environmental parameters (Salinity, DO, Chi a) were observed consecutively at two stations in the Xiamen Bay during No. 9810 typhoon (October, 1998), Bilis typhoon( August, 2000) and rainstorm (June, 2000) processes. Variation of DIN and DIP during the influence period and the recovery period were described. Influence of water dynamics, sediment resuspension, decomposition of organic matter and biological activity on variation of DIN and DIP were initially discussed.国家自然科学基金项目49776301

Fluorescence Excitation-Emission Matrix Spectroscopy of CDOM from Yundang Lagoon and Its Indication for Organic Pollution

测定了2008年4~5月厦门筼筜湖52个CdOM样的三维荧光及吸收光谱,以探讨利用其光谱特征示踪高污染近海浅水湿地生物修复过程中有机污染程度的可行性。利用平行因子分析对三维荧光光谱进行解谱。结果表明,筼筜湖CdOM可识别出3类5个荧光组分,包括类腐殖质荧光组分C1(240,325/422nM)和C5(260,380/474nM)、类蛋白质荧光组分C2(225,275/350nM)和C4(240,300/354nM)以及有机污染组分C3(225/342nM),其中C3可作为外来有机污染物输入的指纹特征。松柏湖干渠及污水处理厂排放口C3组分及dOC浓度很高,表明周边污水输入是筼筜湖有机污染的主要来源。类腐殖质荧光组分C1及吸收系数A(280)与COd之间、类蛋白质荧光组分C2与bOd5之间均具有很好的线性相关关系,表明CdOM的光谱特性可很好地指示有机污染程度,对评价有机污染严重水域生物修复作用机理及效果有重要的参考价值。Fluorescence excitation-emission matrix spectroscopy (EEMs) combined with absorption spectroscopy were applied to study the optical properties of CDOM samples from highly-polluted Yundang Lagoon in Xiamen in order to demonstrate the feasibility of using these spectral properties as a tracer of the degree of organic pollution in similar polluted coastal waters.Surface water samples were collected from 13 stations 4 times during April and May,2008.Parallel factor analysis (PARAFAC) model was used to resolve the EEMs of CDOM.Five separate fluorescent components were identified,including two humic-like components (C1:240,325/422 nm;C5:260,380/474 nm),two protein-like components (C2:225,275/350 nm;C4:240,300/354 nm) and one xenobiotic-like component (C3:225/342 nm),which could be used as a good tracer for the input of the anthropogenic organic pollutants.The concentrations of component C3 and dissolved organic carbon (DOC) are much higher near the inlet of sewage discharge,demonstrating that the discharge of surrounding sewage is a major source of organic pollutants in Yundang Lagoon.CDOM absorption coefficient a(280) and the score of humic-like component C1 showed significant linear relationships with CODMn,and a strong positive correlation was also found between the score of protein-like component C2 and BOD5.This suggested that the optical properties of CDOM may provide a fast in-situ way to monitor the variation of the water quality in Yundang Lagoon and that of similar polluted coastal waters.国家(863计划)项目(2007AA091704);国家自然科学基金项目(40776041;40676046);新世纪优秀人才支持计划项目资

马铃薯重离子辐射育种研究

在2000—2005年将杂交技术和重离子辐射相结合,采用55MeV/u的40Ar17+离子对马铃薯杂交种子和微型薯进行了不同剂量的贯穿辐射或离子注入处理。结果表明,对马铃薯微型薯进行重离子辐射能显著提高块茎的产量。而杂交技术和重离子辐射相结合是一种更高效的育种方式,不仅能提高块茎的增产幅度,还能改善其加工品质。微型薯重离子辐射的最佳剂量为60Gy,杂交种子辐射的适宜剂量范围在60—120Gy之间。通过对辐射后代的多年选育,获得了几个产量显著高于对照、品质优良的马铃薯新品系