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以2008年10月和2009年5月黄河口和辽河口芦苇湿地野外调查获取的数据为基础,研究中国北方典型河口芦苇湿地表层和剖面土壤有机碳库的分布特征,并探讨其土壤有机碳库差异的原因。结果表明:5和10月份,黄河口芦苇湿地表层土壤有机碳变幅分别为2.15~10.13和10.98~28.82kg/m3,无显著性季节差异;辽河口芦苇湿地表层土壤有机碳库变幅分别为0.8~31.38和18.95~68.7kg/m3,10月份显著高于5月份。两河口剖面土壤有机碳库分布特征相同,均表现为0~10cm土层含量明显高于各底层,0~20cm土层集中了整个剖面50%以上的有机碳。辽河口芦苇湿地表层土壤有机碳含量及碳库均高于黄河口湿地,且10月份其差异达到了显著性水平。相对于我国其它河口芦苇湿地,黄河口湿地有机碳含量严重偏低,具有很大的可提升潜力。辽河口湿地芦苇地上生物量的均值达到2.96kg/m2,是黄河口的5.82倍,而表观土壤呼吸通量显著低于黄河口湿地,有机碳的高输入和低输出是其土壤有机碳库高于黄河口湿地的根本原因;土壤盐渍化程度高、黏粒含量低和氮素匮乏是影响黄河口芦苇湿地土壤有机碳库严重偏低的主要因素。因此,在开展黄河口退化湿地的生态恢复重建技术中降低土壤盐渍化程度、提高黏粒含量和全氮含量是提高土壤有机碳库的关键。 相似文献
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辽河口湿地碳、氮、磷空间分布及季节动态特征 总被引：2，自引：0，他引：2
以2008年10月和2009年5月2次对辽河口湿地野外调查获取的数据为基础,研究了辽河口湿地生源要素碳、氮和磷的时空分布特征、湿地植被对营养元素的累积及对土壤营养元素氮、磷分布的影响.结果表明:辽河口湿地表层土壤有机碳5月和10月含量分别在0.62～13.17 mg/g和11.06～40.74 mg/g之间,10月盐化草甸土和滨海沼泽盐土有机碳含量较高,5月4种类型土壤有机碳含量无明显差异;全氮5月和10月含量分别在0.80～3.43 mg/g和0.77～2.90mg/g之间,盐化草甸土和滨海沼泽盐土表层土壤氮含量相对较高,滨海潮滩盐土最低;无机氮(NH4+-N和NO3--N)含量较低,且以铵态氮为主,5月略高于10月含量;全磷含量均在0.36～0.66 mg/g之间,无显著季节差异.碳、氮和磷的垂直剖面分布特征表明,土壤表层有机碳、全氮、无机氮和全磷含量明显高于各底层,以芦苇为主要植被的盐化草甸土各剖面的营养元素含量高于以翅碱蓬为主的滨海潮滩盐土含量.5月芦苇对氮磷的积累量高于10月,且氮磷含量在芦苇地上器官的分布趋势为叶>茎>穗.植被的生长对湿地土壤中生源要素碳、氮和磷含量的季节变化有重要影响,其对营养元素氮、磷的累积降低了表层土壤中氮、磷的储量. 相似文献
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土壤铁氧化物结合态有机碳是有机碳长期维持的主要途径,但其机理研究仍较为薄弱。为探究河口湿地围垦稻田对土壤铁碳结合特征的影响,本研究选择福建省闽江河口天然芦苇湿地与围垦稻田为研究对象,对两种类型土壤中的铁结合态有机碳(Fe-OC)及其相关指标进行测定与分析。结果显示：(1)芦苇湿地围垦稻田改变了土壤氧化还原过程,显著影响土壤中铁相的转化。围垦后土壤二价铁[Fe(Ⅱ)]、三价铁[Fe(Ⅲ)]、活性总铁含量(HCl-Fet)及Fe(Ⅲ)/Fe(Ⅱ)分别显著下降了24.68%、52.56%、 51.45%、 35.68%(P<0.05)。游离态氧化铁(Fed)与无定形态铁(Feo)含量分别显著下降了21.64%和29.24%(P<0.05),络合态铁(Fep)含量则有所增加。(2)芦苇湿地围垦稻田显著影响土壤碳固存,Fe-OC与土壤有机碳含量(SOC)在围垦稻田后分别显著下降了39.03%和18.42%(P<0.05);芦苇湿地与稻田土壤Fe-OC均主要以吸附途径结合,稻田土壤Fe-OC对土壤有机碳的贡献率(f... 相似文献
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黄河三角洲北部湿地多环芳烃分布与来源 总被引：4，自引：0，他引：4
对黄河三角洲北部湿地表层土壤中的多环芳烃（PAHs）进行定量分析，结果表明，袁层土壤中PAHs总量范围为27．43～128．97ng／g（干重），PAHs的空间分布总体呈西高东低的趋势。经过研究对比，认为表层土壤样品中的PAHs尚未对生物造成显著负面影响，并提出表层土壤PAHs污染主要来源于高温热解产物，仅有很小部分的石油类的污染。 相似文献
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本文通过现场采集盘锦芦苇湿地不同植被状态区域土壤样品,测定土壤中石油降解菌数量、酶活性和石油烃含量,研究了河口湿地不同芦苇植被状况下石油降解微生物活性的分布特征及影响因素,并探讨了芦苇湿地自然净化能力特征.结果表明,盘锦湿地石油降解微生物活性与湿地芦苇的植被状况相关,芦苇的存在明显提高了石油降解微生物的活性,促进了湿地中石油污染物的降解;脱氢酶活性与石油烃含量极显著正相关(P＜0.01),脱氢酶活性可代表土壤中石油降解过程的生物活性状态;土壤中的N、P含量、pH值和含水率是影响微生物活性的主要因素,芦苇根际可以改善土壤理化性质而有利于微生物的生长.人工恢复芦苇增强了土壤中石油降解生物活性,提高了湿地净化能力,是保护河口湿地生态功能的有效措施.研究结果可为河口湿地石油污染物的生物净化能力研究及生物修复效果评估提供科学依据. 相似文献
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海南八门湾红树林柱状沉积物中有机生物标志物的分布和降解 总被引：1，自引：0，他引：1
对海南岛红树林柱样中有机生物标志物等生物地球化学参数进行了初步研究.结果显示红树林中有机碳(OC)与总氮(TN)比值范围为5.35-7.47,碳稳定同位素(δ13C)值范围为-25‰--22.9‰.脂肪酸与正构烷烃浓度分布范围分别为7.8-21.8μg·g-1(干重)和3.2-25μg·g-1(干重).在表层沉积物中,红树林植物、细菌与浮游生物的脂肪酸生物标志物各占总脂肪酸的25.4%、12.9%和7.5%,结合较低的OC/TN比值和较高的δ13C值,表征了当地微生物和外源浮游植物的有机质贡献.各类脂肪酸在柱样中表现出不同的降解特征:多不饱和脂肪酸(PUFAs)优先被降解,而长链脂肪酸(LCFAs)则较为稳定,没有明显的降解.碳优势指数(CPI)和平均碳链长度(ACL)显示,埋藏深度越深,有机物的生物化学改造程度越大. 相似文献
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乳山湾外低氧海域沉积物中有机碳、氮、磷及其形态特征分析 总被引：3，自引：0，他引：3
根据2009年8月在乳山湾及其毗邻海域的综合调查,分析了该海域表层沉积物中有机碳、氮、磷含量及其组成形态的变化,初步探讨了影响底质理化参数变化的原因及对乳山湾外近岸底层低氧形成的影响.结果表明,乳山湾外近海为粉砂质岸滩,以细颗粒为主;底质中有机碳含量介于0.49％ ～0.93％,平均值为0.69％;总氮含量介于382～1020 mg/kg,平均值为671 mg/kg;可溶性总氮含量介于23.0 ～ 60.0 mg/kg,平均值为44.0mg/kg,其中可溶性有机氮和氨氮分别占可溶性总氮的58.8％和38.8％;总磷含量介于138～769 mg/kg,平均值为356 mg/kg,有机磷是占有绝对优势的磷形态(62.5％).研究区域沉积物中总氮和湾内相当,有机碳、总磷含量普遍低于乳山湾内,但均明显高于南黄海区域,且呈还原性状态.调查区域内沉积物中相对较高的有机碳、氮、磷可能是在潮流作用下乳山湾与外海的物质交换所致,其耗氧过程是导致底层溶解氧亏损的重要原因,值得进一步关注. 相似文献
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《中国海洋大学学报(自然科学版)》2017,(6)
以黄河三角洲芦苇湿地为研究对象,通过土壤有机碳(SOC)矿化过程室内模拟,研究了土壤有机碳矿化动态特征,探讨了土壤有机碳含量、水分和盐渍化程度对土壤矿化过程的影响,明确了土壤有机碳矿化的主控因子。结果表明:土壤累积矿化量随时间呈指数增长趋势,培养前期(0~10d)土壤累积矿化量约占整个培养周期总累积矿化量的50%左右;培养中期(11~35d)土壤矿化速率明显下降,前35天土壤累积矿化量约占整个培养周期总累积矿化量的85%;培养后期(36~70d)土壤矿化速率趋于平缓。多因素方差分析显示,土壤有机碳含量、水分和盐渍化程度对土壤有机碳的矿化作用均有显著影响(P0.05)。其中,SOC的含量是影响矿化最主要的因素(F_(0.05)=3711,P0.001),其与累积矿化量呈显著的正相关关系(R2adj=0.775,P0.05);土壤水分含量对SOC矿化作用的影响次于有机碳含量(F_(0.05)=71.31,P0.001),盐度对土壤累积矿化量的影响最小(F_(0.05)=33.58,P0.001)。但是,当土壤处于半淹水和淹水状态时,强度盐渍化、有机碳含量低的O1处理组土壤累积矿化率高于土壤有机碳含量高的各个O3处理组。因此,滨海湿地土壤有机碳含量较低、盐渍化程度较高的退化湿地土壤的CO2释放问题应被关注。 相似文献
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以盐城滨海湿地为例,基于遥感影像提取土地利用变化信息,估算了1987-2007年盐城滨海湿地表层(0~20 cm)土壤有机碳储存量和滨海湿地土壤固碳能力现状。结果表明:表层土壤有机碳储量1992年较1987年略有增长,1992~2002年间下降33.3%,2002~2007年间增加30.5%。自然湿地面积减少是湿地土壤有机碳储量减少的主要原因,而互花米草入侵和围垦造田造成了湿地土壤有机碳储量增加。农田、芦苇滩、碱蓬滩、互花米草滩和光滩有机碳埋藏速率分别为12.90、0.30、0.80、2.92和1.68×104 t/a。滩涂围垦造田在短期内有利于滨海湿地土壤有机碳储量增加,但淤泥质滨海湿地生态系统在淤长过程中的自然演替过程,能使整个湿地具有更高、更持久的固碳能力。本研究建议合理控制围垦速率,才能在获取经济社会利益最大化的同时,保证湿地土壤有机碳储量持续增加。 相似文献
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Evaluation of atmospheric transport as a nonpoint source of polycyclic aromatic hydrocarbons in marine sediments of the Eastern Mediterranean 总被引：1，自引：0，他引：1
Coastal marine sediment, air and seawater samples were collected at six sampling stations in the Eastern Mediterranean Sea distant from pollutant point sources. All sediment samples were analyzed to determine polycyclic aromatic hydrocarbon (PAH), black carbon (BC) and organic carbon (OC) contents. The PAH contents of gaseous and seawater samples of the study were determined in order to evaluate the role of air–sea exchange as PAH nonpoint source to the marine sediments. The average concentration of the total PAHs (∑PAHs) in the sediments varied from 2.2 to 1056.2 ng g−1 dry weight. The average BC and OC contents varied from 0.3 to 5.6 and from 2.9 to 21.4 mg g−1 dry weight, respectively. ∑PAH concentration in the marine atmosphere varied from 20.0 to 83.2 ng m−3. Air–water exchange flux (FA–W) estimation has indicated air transport as a significant source of PAHs to pristine marine sediments of Eastern Mediterranean. In addition, the significant correlation between the PAHs and the organic and soot carbon content further suggests the importance of atmospheric input of PAHs to the sediments. 相似文献
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沉积物插管短柱样品于2013年4月采自大连湾2010年“7·16”溢油事故污染区,BQ050站与BQ007站分别位于生物分散剂和化学分散剂喷洒区。沉积物的可溶有机质含量(沥青A)、有机碳同位素组成(δ13Corg)和210Pb比活度分析结果表明:喷洒生物分散剂的重污染区(BQ050站),沉积物中TOC含量为0.58%～1.51%,平均为1.15%;δ13Corg值为-22.2‰～-20.5‰PDB,平均为-21.74‰PDB;沥青A含量为0.061 5%～0.566 4%,平均为0.174 9%;沥青A/TOC比值为7.0%～34.8%,平均为14.13%;210Pbex比活度存在异常峰值分布,垂向分布特征与沥青A相似;2～16 cm段沉积物的可溶有机质具有明显的外来输入特征。喷洒化学分散剂的较轻污染区(BQ007站),沉积物中TOC含量为0.61%～1.14%,平均为0.87%,除8～14 cm层段外,比BQ050站略低;但沥青A含量与沥青A/TOC比值明显低于前者;δ13Corg值较BQ050站轻;210Pbex比活度随柱样深度呈指数衰减,对数相关;外来有机质输入量较低。截至2013年4月,BQ050站溢油污染物在海底下16 cm深度处有特征信号,溢油污染物沥青A 组分垂向迁移距离约为15 cm。 相似文献
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Contents of heavy metals, polycyclic aromatic hydrocarbons （PA Hs）, dichlorodiphenyltrichloroethanes （DDTs） and hexachlorcy- clohexanes （HCHs） in surface sediments from mangrove areas of the Leizhou Peninsula were analyzed in July and November 2005. Risk assessment criteria applied by Long E R et al. （1995） and Long E D et al. （1995） （effects range low, ERL; effects range mean, ERM） of chemicals in sediments from the gulf or estuary were used to assess the potential ecological risks of heavy metals, PAHs, DDTs and HCHs to aquatic organisms in the studied area. The results indicated that the average contents of zinc, nickel, chromium, lead, copper, arsenic and mercury were （61.97 ± 55.87）, （59.99 ± 39.01 ）, （47.93 ± 28.37）, （26.64± 13.00） , （23.45 ± 41.96）, （9.32 ± 3.62）, （0.14 ± 0.18） mg/kg in dry weight in the sediment samples col- lected from five studied sites in the Leizhou Peninsula, respectively. Cadmium was not calculated due to its content being below the detection limit （ 〈 0.3 mg,/kg）. The average levels of Cr, Cu, Ni, Pb, Zn and Hg exceed their background values. The average contents of Ni were higher than ERM. The contents of PAHs in the sediments from the five studied sites were （79.78 ± 43.70） ng/g in dry weight, far lower than ERL（4 022 ng/g）. The contents of DDE, DDD and DDTs in the sediments from five studied sites were （2.60 ± 4.68）, （ 17.52 ± 27.25 ）, （27.78 ± 46.64） ng/g in dry weight respectively, clearly higher than ERL, and the average contents of DDT were （7.66 ± 15.93） ng/g in dry weight, much higher than ERM. HCHs could be detected in the sediments only from Gaoqiao sampling site, with the average contents （0.07 ± 0.08） ng/g in dry weight. 相似文献
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胶州湾沉积物中氨基酸对有机质降解及细菌源贡献的指示作用解析 总被引：2，自引：2，他引：0
基于对胶州湾表层沉积物中总可水解氨基酸（THAA）的含量、组成、构型及分布特征的系统研究，通过氨基酸碳氮归一化产率（THAA-C%，THAA-N%）、降解因子DI、反应活性指数RI以及D型氨基酸占比（D-AA%，摩尔百分比）等指标结合碳氮比（TOC/TN）、碳稳定同位素（δ13C）探析了胶州湾沉积物中有机质的来源与降解状态，利用细菌源有机质及胞外肽酶活性（EEA）探讨了微生物在有机质迁移转化过程中的作用与贡献。结果表明，胶州湾表层沉积物中氨基酸平均含量为（7.60±3.64）μmol/g，在陆源与海源混合影响下，其水平分布呈现湾内高于湾外、湾内东部高于西部的特点，表明湾内东部陆源输入对沉积物THAA具有较高贡献。THAA-C%、THAA-N%、DI、RI以及D-AA%等指示因子均显示胶州湾表层沉积物中有机质的降解程度呈现湾外高于湾内、湾内东部高于西部的变化趋势，有机质来源、微生物活性与上覆水水深共同影响了有机质的降解程度。胶州湾表层沉积物中细菌源有机碳的贡献率为（29.35±18.73）%，其水平分布显示出湾内西部与湾外相近且高于湾内东部的特点。细菌胞外肽酶活性（EEA）平均为（0.81±1.31）nmol/（g·h）（以MCA计），整体分布趋势与细菌贡献率相反，呈现湾内东部高于湾内西部和湾外的特性。沉积物中有机质的不同海源、陆源占比决定了有机质的可降解性，而有机质的降解程度进一步影响了细菌源有机质的贡献与胞外肽酶活性。 相似文献
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本文选取了辽宁省盘锦市红海滩6个采样点的沉积物,通过测定其中重金属和石油各组分的含量,调查盘锦红海滩的重金属和石油的污染情况。结果表明,各采样点中除退化区的Cu和茂盛区的Pb含量高于《海洋沉积物质量标准》(GB18668-2002)Ⅰ类标准外,其他各区域重金属含量均低于(GB 18668-2002)Ⅰ类标准。茂盛区的植物必需金属Fe、Mg、K含量在36.9～46.1 g/kg之间,高于退化区和光滩区的30.7～38.0 g/kg;退化区和茂盛区的土壤样品含油浓度较高,在1.6～5.2 mg/kg之间,光滩区的土壤样品含油浓度较低,为2.5mg/kg,均远低于(GB18668-2002)Ⅰ类标准500mg/kg;退化区的土壤中多环芳烃各组分含量在0.4～51.8ng/g之间,相比于其他地区的0.2～25.0ng/g较高,而光滩区土壤中多环芳烃各组分含量在0.2～3.8 ng/g之间,相比于其他地区的0.3～51.8 ng/g较低;不同区域土壤正构烃的组成(C10～C35)基本相同,但是分布特征存在较大差别。 相似文献
17.
Understanding the hydrocarbon accumulation pattern in unconventional tight reservoirs is crucial for hydrocarbon evaluation and oil/gas extraction from such reservoirs. Previous studies on tight oil accumulation are mostly concerned with self-generation or from source to reservoir rock over short distances. However, the Lucaogou tight oil in Jimusar Sag of Junggar Basin shows transitional feature in between. The Lucaogou Formation comprises fine-grain sedimentary rocks characterized by thin laminations and frequently alternating beds. The Lucaogou tight silt/fine sandstones are poorly sorted. Dissolved pores are the primary pore spaces, with average porosity of 9.20%. Although the TOC of most silt/fine sandstones after Soxhlet extraction is lower than that before extraction, they show that the Lucaogou siltstones in the area of study have fair to good hydrocarbon generation potential (average TOC of 1.19%, average S2 of 4.33 mg/g), while fine sandstones are relatively weak in terms of hydrocarbon generation (average TOC of 0.4%, average S2 of 0.78 mg/g). The hydrocarbon generation amount of siltstones, which was calculated according to basin modeling transformation ratio combined with original TOC based on source rock parameters, occupies 16%–72% of oil retention amount. Although siltstones cannot produce the entire oil reserve, they certainly provide part of them. Grain size is negatively correlated with organic matter content in the Lucaogou silt/fine sandstones. Fine grain sediments are characterized by lower deposition rate, stronger adsorption capacity and oxidation resistance, which are favorable for formation of high quality source rocks. Low energy depositional environment is the primary reason for the formation of siltstones containing organic matter. Positive correlation between organic matter content and clay content in Lucaogou siltstones supports this view point. Lucaogou siltstones appear to be effective reservoir rocks due to there relatively high porosity, and also act as source rocks due to the fair to good hydrocarbon generation capability. 相似文献
18.
Distributions and sources of bulk organic matter and aliphatic hydrocarbons in surface sediments of the Bohai Sea, China 总被引：11，自引：0，他引：11
Surface sediment samples from a matrix of fifty-five sites covering virtually the entire Bohai Sea (Bohai), China were analyzed for total organic carbon (TOC), total nitrogen (TN), n-alkanes, unresolved complex mixture (UCM), biomarkers and stable carbon isotopic composition (δ13C), and principal component analysis was performed for source identification of organic matter (OM). The distribution of organic carbon correlated well with sediment grain size with the finest sediments having the highest concentration, suggesting the influence of hydrodynamics on the accumulation of sedimentary organic matter (SOM). The corrected TOC/ON (organic nitrogen) ratios and δ13C indicated mixed marine and terrestrial sources of SOM. Results suggested that δ13C could be used as a potential indicator to observe the dispersion of Huanghe-derived sediments in Bohai. Total n-alkane concentrations varied over 10-fold from 0.39 to 4.94 μg g− 1 (dry weight) with the maximum terrigenous/aquatic alkane ratio observed at the Huanghe River Estuary (HRE) due to more higher plant OM from riverine inputs. C12–C22 n-alkanes with even-to-odd predominance were observed in several central-eastern Bohai sites. The HRE and its adjacent area is the main sink for the Huanghe river-derived OC. The ubiquitous presence of UCM, biomarkers (hopanes and steranes) and PCA results indicated the presence of petroleum contamination in Bohai, mainly from offshore oil exploration, discharge of pollutants from rivers, shipping activities and atmospheric deposition. 相似文献
19.
The geochemical and petrographic characteristics of saline lacustrine shales from the Qianjiang Formation, Jianghan Basin were investigated by organic geochemical analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM) and low pressure nitrogen adsorption analysis. The results indicate that: the saline lacustrine shales of Eq3 member with high oil content are characterized by type I and type II oil-prone kerogen, variable TOC contents (1.0–10.0 wt%) and an early-maturity stage (Ro ranges between 0.41 and 0.76%). The mineral compositions of Eq3 saline shale show strong heterogeneity: brittle intervals with high contents of quartz and carbonate are frequently alternated with ductile intervals with high glauberite and clay contents. This combination might be beneficial for oil accumulation, but may cause significant challenges for the hydraulic stimulation strategy and long-term production of shale oil. The interparticle pores and intraparticle pores dominate the pore system of Eq3 shale, and organic matter hosted pores are absent. Widely distributed fractures, especially tectonic fractures, might play a key role in hydrocarbon migration and accumulation. The pore network is contributed to by both large size inorganic pores and abundant micro-factures, leading to a relatively high porosity (2.8–30.6%) and permeability (0.045–6.27 md) within the saline shale reservoir, which could enhance the flow ability and storage capacity of oil. The oil content (S1 × 100/TOC, mg HC/g TOC and S1, mg HC/g rock) and brittleness data demonstrate that the Eq33x section has both great potential for being a producible oil resource and hydraulic fracturing. Considering the hydrocarbon generation efficiency and properties of oil, the mature shale of Eq3 in the subsidence center of the Qianjiang Depression would be the most favorable zone for shale oil exploitation. 相似文献
20.
山东南部近海沉积物中碳、氮、磷的分布特征 总被引：4，自引：0，他引：4
对山东近海31个站位表层沉积物中的总氮、总磷和总有机碳的含量和分布特征进行了研究。结果表明,总氮、总磷和总有机碳含量均较低,高值区主要分布在胶州湾及湾口和北部海域,总氮浓度范围为0.31～0.75mg/g,平均值为0.52mg/g,总磷浓度范围为0.18～0.32mg/g,平均值为0.24mg/g,总有机碳浓度范围为0.17%～0.49%,平均值为0.33%。相关性分析表明,总氮和总有机碳的相关性较好,总有机碳和总氮比值(TOC/TN)略高于Redfield比值,表明这两种生源要素的来源可能是一致的。 相似文献