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Leonardo M. Furlanetto Claudio C. MarinhoCleber Palma-Silva Edélti F. AlbertoniMarcos Paulo Figueiredo-Barros Francisco de Assis Esteves 《Limnologica》2012,42(2):151-155
The vertical sediment profiles (10 cm) of the margins of three shallow subtropical lakes (Rio Grande, Brazil) with different trophic states and surrounding areas were evaluated to identify the effects of the allochthonous input on the methane concentration in the sediment. Sediment cores were collected to quantify the organic matter content (OM) and total carbon (TC), total nitrogen (TN), total phosphorous (TP) and methane (CH4) concentrations.The three lakes were distinguished according to the trophic status and classified as oligotrophic, dystrophic and eutrophic. The natural characteristics of the dystrophic and eutrophic lakes have been changed due to the allochthonous input of leaves and twigs (Eucalyptus sp.) and the excreta of birds, respectively. In the eutrophic lake, the allochthonous input contributed to high autochthonous production. The highest values of OM, TC, TN and TP were found in the superficial sediments of the dystrophic and eutrophic lakes. The accumulation of allochthonous organic matter in the littoral zone promoted changes in the vertical sediment profiles and contributed to increases in the CH4 concentrations in the sediment. 相似文献
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太湖沉积物理化性质及营养盐的时空变化 总被引：10，自引：3，他引：7
在不同季节,采集太湖梅梁湾和贡湖湾沉积物柱状样,研究沉积物Eh、pH、总氮、总磷以及有机质四季垂向剖面分布变化特征.研究结果表明,在表层下(0-3 cm),Eh随沉积物深度的增加迅速下降,很快进入还原状态.沉积物剖面上pH变化幅度不大,在6.4-7.8之间,冬季沉积物pH均有所降低.太湖沉积物中含有丰富的营养盐,总氮和总磷最高浓度分别为2.68和0.864 mg/g,其剖面分布特征表明,沉积物表层总氮和总磷含量远高于底层,其含量随深度增加而降低,但四季变化趋势不明显.沉积物中有机质含量在10 cm以上变化幅度较大,随着沉积物深度的增加,有机质含量明显减少,季节变化幅度不大.比较不同采样点发现,位于梅梁湾生态系统试验区内的S1位点沉积物氮磷内源负荷最大. 相似文献
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Changes in carbon and nitrogen cycling in a floodplain lake over recent decades linked to littoral expansion,declining riverine influx,and eutrophication 总被引：1，自引：0，他引：1 
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下载免费PDF全文 This study aimed to understand changes in the biogeochemical processing of organic matter (OM) in response to multiple stressors (e.g., littoral area expansion, wastewater input, and hydrological regulation) in East Dongting Lake (Central China) over the past 60 years, using analyses of total organic carbon (TOC), total nitrogen (TN), C/N ratios, δ13C, δ15N, and diatoms from 2 sediment cores collected from the littoral and central parts of the lake. OM mainly originated from phytoplankton and C3 plant‐derived soil OM based on the ranges of C/N ratios (from 7 to 11) and δ13C (between ?27‰ and ?23‰). Littoral area expansion due to siltation caused an increasing influx of terrestrial soil OM in the 1980s and the 1990s, subsequently lowering δ13C values and rising C/N ratios in both sediment cores. Meanwhile, higher δ15N was linked to a high influx of isotopically heavy nitrate from urban and agricultural wastewaters. After 2000, slight decreases in TOC and TN in the littoral area were attributable to reducing inputs of external OM, likely linked to declining sediment influx from the upper reaches resulting from the Three Gorges Dam impoundment. Contrasting increases in TOC, TN, and C/N ratios in the central part indicated a high influx of terrestrial soil OM due to the declining distance from the shoreline with littoral area expansion. Declining δ15N values after 2000 indicated an increase in N2‐fixing cyanobacteria with eutrophication. Changes in diatom assemblages in both the littoral and central zones reflected nutrient enrichment and hydrological alterations. These results indicate that littoral expansion, declining riverine influx, and anthropogenic nutrient inputs are potential driving forces for the biogeochemical processing of OM in floodplain lakes. This study provides sedimentary biogeochemical clues for tracking past limnological conditions of floodplain lakes that are subjected to increasing disturbances from hydrological regulation and eutrophication. 相似文献
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太湖五里湖生态重建示范工程—大型围隔试验 总被引：35，自引：5，他引：30
五里湖是太湖北部富营养化程度最为严重的一湖湾．从2004年1月起,为了改善水质,重建五里湖生态环境,在五里湖南岸建立了一个面积为10×104m2示范工程试验区,采用多技术措施集成应用,开展湖泊生态重建技术研究．经过近2年的生态重建研究与实践,在示范工程试验区内建立了挺水植物、浮叶植物和沉水植物群丛23个,水生植物种类从生态重建前的零上升至15科、22属、32种,水生植物的多样性指数(Shannon-Wieher index)达到2．33,覆盖度达到40％- 55％．水质监测结果表明,示范工程区内水体的TN、TP、NH4-N、NO3-N、NO2-N及PO4-P的平均值分别比示范工程区外下降了20．7％、23．8％、35．2％、21．1％、45．6％和54．0％,TN、TP分别下降至2．50mg／L、0．080mg/L以下,水质得到明显改善,达到或低于“浅水湖泊稳态转换理论”指出的向“稳定清水态”转换的临界值,水体透明度(SD)平均值也有较大幅度提高,平均从0．39m提高至0．70m;初步实现湖泊水体从藻类占优势浊水态向大型水生植物占优势的清水态转变．因此重建与恢复湖泊生态系统要从沿岸带着手,首先重建湖滨带结构与功能,通过湖滨带水生生物一系列反馈机制, 逐步改善湖泊水质,最终实现沉水植被恢复;湖泊敞水区应主要采用生物操纵技术措施来实现湖泊生态恢复． 相似文献
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基于2010-2019年洪泽湖湖体水质逐月监测数据,筛选出影响湖体水质的主要污染物指标为总氮（TN）和总磷（TP）;选取洪泽湖周边25条主要入湖河流和2条出湖河流在2019年10月2020年9月的监测数据,探讨河流外源性输入对不同湖体区域氮磷的影响及其水期变化规律.结果发现：①湖体TN、TP浓度长期居高不下,年均浓度范围分别在1.39~1.86、0.080~0.171 mg/L波动.主要入湖河流TN、TP时空平均浓度（1.92~5.70和0.114~0.181 mg/L）,均高于同区域湖体（1.15~1.46和0.088~0.101 mg/L）,其中北部入湖河流肖河、马化河和五河与临近湖区TN、TP浓度呈现显著正相关,是影响北部湖体TN、TP浓度的主要河流;南部入湖河流维桥河和高桥河是临近湖区非极端降雨期TN、TP的主要来源.②调水工程对湖体及入湖河流TN、TP浓度分布影响显著,调水期湖体沿调水方向TP浓度逐渐上升,TN浓度则呈现先降后升的趋势,南部入湖河流维桥河和高桥河TN浓度达到水期峰值,分别为10.69和9.90 mg/L.③极端降雨期入湖河流的TN、TP浓度显著高于其它水期,由于湖体对TN、TP的富集作用不同,TP浓度呈现中间高,四周低,而TN浓度呈现沿洪水流向逐渐降低的规律. 相似文献
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坦噶尼喀湖东北部入湖河流表层沉积物中磷的形态和分布特征 总被引：4，自引：0，他引：4
磷是坦噶尼喀湖生态系统中必不可少的营养元素,直接决定湖体初级生产力的高低,进而影响到周边居民对于动物蛋白的获取来源.为了解坦噶尼喀湖磷的外源输入,选择湖泊东北部的入湖河流,对表层沉积物(16个样点)中总磷(TP)和各形态磷含量及其分布特征进行分析,并探讨磷的形态分布特征与土地利用方式之间的相关关系.结果表明,入湖河流沉积物TP含量为73.05~239.94 mg/kg,平均含量为152.64±55.37 mg/kg,其中最高值出现在马拉加拉西河口.采用Psenner法对磷进行连续浸提并比较不同形态磷含量,由高及低依次为铁铝结合态磷(Fe/Al-P)钙结合态磷(CaP)有机磷(Org-P)残渣态磷(Res-P)弱吸附态磷(Labile-P).土地利用类型对TP及各形态磷含量影响较大,其中TP含量表现为河口湿地城镇附近林草地区,表明地表径流和人类活动会对TP含量产生影响,而对于不同形态磷含量,Laible-P、Fe/Al-P、Org-P含量均表现为河口湿地林草地城镇附近,Ca-P、Res-P含量均表现为城镇附近河口湿地林草地.分析沉积物理化性质与各磷形态之间的相关性,发现沉积物总氮(TN)、有机质和总有机碳与Fe/Al-P、LabileP和TP相关性较好,与Org-P、Ca-P和Res-P相关性较差,表明TN和有机质的输入,会伴随沉积物中磷含量的升高,其增量的赋存形态主要为氧化还原敏感态磷和Labile-P.沉积物粒径组成与各磷形态含量存在相关性,细粒径沉积物与各形态磷含量呈显著正相关,粗粒径沉积物与各形态磷呈显著负相关,表明细小颗粒更易吸附磷. 相似文献
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沉水植物附植生物膜藻类组成及重金属累积特征 总被引：2，自引：1，他引：1
沉水植物表面常富集水体中有机质、泥沙、菌胶团、藻类、微生物等形成附植生物膜,在湖泊生物地球化学循环过程中具有重要作用.在草海选取金鱼藻（Ceratophyllum demersum）、微齿眼子菜（Potamogeton maackianus）和光叶眼子菜（Potamogeton lucens L.）3种不同叶形的沉水植物,研究附植生物膜的形貌结构、理化特征、藻类及其重金属镉（Cd）、铅（Pb）累积特征.结果表明：3种沉水植物附植生物膜上共鉴定出藻类6门8纲17目29科65属81种,主要为蓝藻、绿藻和硅藻,不同附植生物膜藻类功能群组成不同,冗余分析表明,水环境因子能解释藻类功能群变化的88.3%;3种沉水植物附植生物膜铁（Fe）、锰（Mn）、总氮（TN）、总磷（TP）含量变化规律一致,均为：金鱼藻 > 微齿眼子菜 > 光叶眼子菜;附植生物膜中重金属的累积具有选择性,Pb大量累积（11.41~41.31 mg/kg）,Cd累积含量较低（0.59~5.76 mg/kg）且与植物相当（0.44~5.56 mg/kg）,附植生物膜中Pb累积含量与生物膜中隐藻门、硅藻门藻类生物量、Fe、Mn及TN含量呈显著相关,但Cd累积与生物膜各指标均无显著相关性.附植生物膜在草型湖泊污染物归趋转化中的作用值得关注. 相似文献
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滇池沉水植物生长过程对间隙水氮、磷时空变化的影响 总被引：4，自引：0，他引：4
2015年6-10月通过原位采集滇池沉水植物分布区和无植物对照区柱状沉积物间隙水,分析其溶解性总氮(DTN)和溶解性总磷(DTP)、溶解性无机氮(DIN)和溶解性无机磷(DIP)及溶解性有机氮(DON)和溶解性有机磷(DOP)浓度的时空变化,探讨沉水植物分布对间隙水氮、磷浓度、形态贡献及氮磷比的影响.结果表明:滇池沉水植物生长过程显著影响间隙水氮、磷浓度.与无植物对照区相比,沉水植物生长过程对间隙水氮浓度的削减主要发生在6、8月,而对间隙水磷浓度的削减主要发生在7月,反映了沉水植物对氮、磷两种元素的生物地球化学循环作用机制不同;间隙水氮形态贡献受季节性影响较大,6-7月以DON贡献为主,沉水植物分布区和无植物对照区分别达到61%和84%;而8-10月以DIN贡献为主,沉水植物分布区和无植物对照区分别为76%和75%;沉水植物分布区磷形态贡献随季节波动变化,沉水植物分布区以DOP贡献为主(63%),无植物对照区以DIP贡献为主(62%);沉水植物生长对沉积物间隙水各形态氮磷比影响显著.沉水植物生长显著增加间隙水DTN/DTP比,尤其是DIN/DIP比,相反降低DON/DOP比.沉水植物对间隙水氮、磷吸收及转化过程改变了沉积物氮、磷释放机制,从而影响上覆水氮、磷组成及氮磷比,很可能会影响到浮游植物生长及藻类水华过程,这对于湖泊水质管理具有重要意义. 相似文献
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亚热带地区典型水库流域氮、磷湿沉降及入湖贡献率估算 总被引：1，自引：0，他引：1
为了探究汤浦水库流域氮、磷湿沉降对水库水体营养的贡献率,本研究对2014 2015年的汤浦水库流域4个采样点的雨水及3条溪流进行样品收集,测定其中磷和不同形态氮的质量浓度,分析汤浦水库流域大气湿沉降中氮、磷营养盐的分布特征,并估算氮、磷营养盐湿沉降对汤浦水库入库负荷的贡献率.结果表明:湿沉降中总氮(TN)平均浓度为1.02±0.58 mg/L,氨氮、硝态氮和有机氮浓度占TN浓度的比例分别为60.65%、34.07%和5.28%;总磷(TP)平均浓度为0.033±0.028 mg/L.4个采样点湿沉降中氮、磷浓度均表现为冬春季(少雨季)高、夏秋季(多雨季)低.空间上,王化点位的各形态氮和总磷浓度显著高于其他3个采样点.TN和TP年均湿沉降通量约为18.15和0.62 kg/(hm~2·a),年均沉降总量为834.94和28.39 t;库区TN和TP水面湿沉降量为24.14和0.82 t,直接贡献率占河流输入的1.77%和3.07%.湿沉降来源的氮、磷营养盐随河流输入的间接贡献率为8.3%和4.6%.综上所述,氮、磷湿沉降是水库外源营养的重要输入部分,深入掌握其时空分布特征及入库贡献率是进一步加强流域管理和减轻水库外源营养输入的重要前提. 相似文献
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三峡库区消落带土壤有机质和全氮含量分布特征 总被引：13，自引：3，他引：10
在三峡库区消落带落干期间(2010年4月),对库区巫山-重庆主城区段消落带土壤有机质(OM)和全氮(TN)含量分布及与土壤理化性质的相关性进行了调查研究.结果表明该区域消落带土壤OM和TN含量均较低,分别为10.70±4.03和0.84±0.39 mg/g,且服从正态分布.消落带土壤碳氮比(C/N)较低,推测消落带土壤无机氮在淹水期间存在向上覆水体释放的可能性.在与其它关于土壤OM和TN含量研究的比较中,研究区域内土壤OM和TN含量处于偏低的水平;而在与对照带样品的比较分析中发现,消落带样品的OM和TN含量变异系数均偏低,因此消落带干湿交替可减小不同区域消落带之间土壤OM和TN含量差异.相关性分析表明,消落带土壤pH、ORP、TN与OM之间呈显著正相关,可见研究范围内消落带土壤氮形态可能主要以有机氮的形式存在于有机质中,而C/N与TN呈负相关,与OM相关性不显著,表明C/N的大小主要取决于TN含量. 相似文献
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以我国南方丘陵区红壤小流域为研究对象,对不同土地利用方式坡面下的4个水塘底泥中养分含量作了分层比较研究(0-5 cm,5-10 cm,10-15 cm,15-20 cm,20-25 cm,25-30 cm)．结果表明:4个水塘底泥养分含量差异明显,在0-15 cm泥层有机碳、全氮、速效氮和全磷含量以邻近村庄的水塘(简称C塘)底泥最高,其次为板栗园坡下的水塘(简称B塘),水稻田坡面下水塘(简称S塘)和花生地坡面下水塘(简称H塘)最低;在15-30 cm泥层,有机碳和速效氮含量以B塘最高,而全氮和全磷含量则以C塘最高;有效磷含量除C塘0-15 cm底泥外,其余均为痕量．表明土地利用方式对其坡面下水塘底泥养分含量影响明显．各水塘底泥养分随泥层加深均呈递减趋势,其中全氮和速效氮减幅以C塘最大,分别为36．0％和38．7％,有机碳和全磷减幅则以B塘最大,为29．4％和31．9％;各塘底泥养分含量的最大降幅主要在浅层底泥,水塘养分积累加速表明近年来农村面源污染加剧．传统农业耕作方式的改变是农村水体底泥养分含量增加的主要原因之一． 相似文献
13.
Estimation of sediment sources using selected chemical tracers in the Perry lake basin,Kansas,USA 总被引：1，自引：0，他引：1
The ability to achieve meaningful decreases in sediment loads to reservoirs requires a determination of the relative importance of sediment sources within the contributing basins. In an investigation of sources of fine-grained sediment （clay and silt） within the Perry Lake Basin in northeast Kansas, representative samples of channel-bank sources, surface-soil sources （cropland and grassland）, and reservoir bottom sediment were collected, chemically analyzed, and compared. The samples were sieved to isolate the 〈63μt m fraction and analyzed for selected nutrients （total nitrogen and total phosphorus）, organic and total carbon, 25 trace elements, and the radionuclide cesium-137 （^137Cs）. On the basis of substantial and consistent compositional differences among the source types, total nitrogen （TN）, total phosphorus （TP）, total organic carbon （TOC）, and ^137Cs were selected for use in the estimation of sediment sources. To further account for differences in particle-size composition between the sources and the reservoir bottom sediment, constituent ratio and clay-normalization techniques were used. Computed ratios included TOC to TN, TOC to TP, and TN to TP. Constituent concentrations （TN, TP, TOC） and activities （^137Cs） were normalized by dividing by the percentage of clay. Thus, the sediment-source estimations involved the use of seven sediment-source indicators. Within the Perry Lake Basin, the consensus of the seven indicators was that both channel-bank and surface-soil sources were important in the Atchison County Lake and Banner Creek Reservoir subbasins, whereas channel-bank sources were dominant in the Mission Lake subbasin. On the sole basis of ^137Cs activity, surface-soil sources contributed the most free-grained sediment to Atchison County Lake, and channel-bank sources contributed the most fine-grained sediment to Banner Creek Reservoir and Mission Lake. Both the seven-indicator consensus and ^137Cs indicated that channelbank sources were dominant for Perry Lake and that channel-bank sources increased in importance with distance downstream in the basin. 相似文献
14.
The changes of NH3-N, NO3-N, NO2-N and TN/TP were studied during growth and non-growth season in 33 subtropical shallow lakes in the middle and lower reaches of the Yangtze River. There were significant positive correlations among all nutrient concentrations, and the correlations were better in growth season than in non-growth season. When TP>0.1 mgL-1, NH3-N increased sharply in non-growth season with increasing TP, and NO3-N increased in growth season but decreased in non-growth season with TP. These might be attributed to lower dissolved oxygen and low temperature in non-growth season of the hypereutrophic lakes, since nitrification is more sensitive to dissolved oxygen and temperature than antinitrification. When 0.1 mgL-1>TP>0.035 mgL-1, TN and all kinds of inorganic nitrogen were lower in growth season than in non-growth season, and phytoplank-ton might be the vital regulating factor. When TP<0.035 mgL-1, inorganic nitrogen concentrations were relatively low and NH3-N, NO2-N had significant correlations with phytoplankton, indicating that NH3-N and NO2-N might be limiting factors to phytoplankton. In addition, TN/TP went down with decline in TP concentration, and TN and inorganic nitrogen concentrations were obviously lower in growth season than in non-growth season, suggesting that decreasing nitrogen (especially NH3-N and NO3-N) was an important reason for the decreasing TN/TP in growth season. The ranges of TN/TP were closely related to trophic level in both growth and non-growth seasons, and it is apparent that in the eutrophic and hypertrophic state the TN/TP ratio was obviously lower in growth season than in non-growth season. The changes of the TN/TP ratio were closely correlated with trophic levels, and both declines of TN in the water column and TP release from the sediment were important factors for the decline of the TN/TP ratio in growth season. 相似文献
15.
区域增温和大气氮沉降作用已成为高山湖泊面临的重要环境胁迫,已有高山湖泊生物群落响应的长期模式研究主要集中于藻类而缺乏更高营养级生物(如浮游动物)的系统调查。本研究选择滇西北地区深水型的高山湖泊沃迪错开展沉积物调查,通过多指标分析(总氮、总磷、叶绿素a、氮稳定同位素等)并结合区域气候重建记录,识别近两百年来该湖泊及流域环境的变化历史,进一步利用枝角类群落指标(物种组成、生物量等)定量评价了湖泊生物群落的响应模式与驱动因子。结果表明,湖泊营养水平(如总氮浓度)和初级生产力(叶绿素a浓度等)在过去近两百年总体呈上升趋势。相关分析显示,大气氮沉降和流域外源输入是影响总氮上升的主要因素,同时区域增温和营养盐富集促进了湖泊初级生产力的不断上升。自1960s以来区域升温明显,湖泊营养水平和叶绿素a浓度呈现加速上升的趋势。钻孔中枝角类群落以浮游属种(Daphnia longispina等)为优势种,在1900AD以前D.longispina相对丰度较为稳定(40.83%±8.02%),之后出现下降趋势且在1948—1965年间明显下降,之后再次明显上升并成为主要优势种。排序分析显示,气温、叶绿素a和总... 相似文献
16.
Cristián Frêne Juan J. Armesto Freddy Véliz Fernando D. Alfaro Kathleen C. Weathers 《水文研究》2021,35(5):e14175
The variability of rainfall-dependent streamflow at catchment scale modulates many ecosystem processes in wet temperate forests. Runoff in small mountain catchments is characterized by a quick response to rainfall pulses which affects biogeochemical fluxes to all downstream systems. In wet-temperate climates, water erosion is the most important natural factor driving downstream soil and nutrient losses from upland ecosystems. Most hydrochemical studies have focused on water flux measurements at hourly scales, along with weekly or monthly samples for water chemistry. Here, we assessed how water and element flows from broad-leaved, evergreen forested catchments in southwestern South America, are influenced by different successional stages, quantifying runoff, sediment transport and nutrient fluxes during hourly rainfall events of different intensities. Hydrograph comparisons among different successional stages indicated that forested catchments differed in their responses to high intensity rainfall, with greater runoff in areas covered by secondary forests (SF), compared to old-growth forest cover (OG) and dense scrub vegetation (CH). Further, throughfall water was greatly nutrient enriched for all forest types. Suspended sediment loads varied between successional stages. SF catchments exported 455 kg of sediments per ha, followed by OG with 91 kg/ha and CH with 14 kg/ha, corresponding to 11 rainfall events measured from December 2013 to April 2014. Total nitrogen (TN) and phosphorus (TP) concentrations in stream water also varied with rainfall intensity. In seven rainfall events sampled during the study period, CH catchments exported less nutrients (46 kg/ha TN and 7 kg/ha TP) than SF catchments (718 kg/ha TN and 107 kg/ha TP), while OG catchments exported intermediate sediment loads (201 kg/ha TN and 23 kg/ha TP). Further, we found significant effects of successional stage attributes (vegetation structure and soil physical properties) and catchment morphometry on runoff and sediment concentrations, and greater nutrients retention in OG and CH catchments. We conclude that in these southern hemisphere, broad-leaved evergreen temperate forests, hydrological processes are driven by multiple interacting phenomena, including climate, vegetation, soils, topography, and disturbance history. 相似文献
17.
湖泊表层沉积物可溶性有机氮含量及分布特性 总被引：8，自引：1，他引：7
选择鄱阳湖、洞庭湖等6个湖泊的15个表层沉积物样品,用1mol/L KCl溶液提取沉积物中的可溶性有机氮(SON),并研究了SON的含量、分布状况及特性.结果表明,所研究的沉积物SON含量变异较大,在17.18-292.31mg/kg之间波动,平均为134.45 mg/kg,占可溶性总氮(TSN)的51.86%,沉积物总氮的7.14%.污染程度重的沉积物中SON含量均较污染程度轻的高,且SON含量与TN、TSN含量呈正相关,即与沉积物氮污染程度呈正相关,分布状况则与湖泊污染程度、人类活动干扰强度等紧密相关,所研究表层湖泊沉积物巾游离氨基酸(FAA)含量处于4.69-42.04mg/kg间,平均为23.27mg/kg,占SON的18.80%,TN的1.24%,FAA与SON含量呈显著正相关,在沉积物中的平均含骨及在SON中的比例均较土壤中高,说明湖泊沉积物SON有较大的易分解组分,SON与沉积物可溶忭无机氮、有机质、CEC等显著相关,因此,SON是湖泊沉积物氮的重要组成部分,对湖泊富营养化具有重要的影响,特别是对污染严重的沉积物而言,更应重视其SON在湖泊氮循环及富营养化中的作用. 相似文献
18.
红枫湖、百花湖沉积物全氮、可交换态氮和固定铵的赋存特征 总被引：39，自引：5，他引：34
氮是引起湖泊水体富营养化的关键营养元素之一。本次工作从贵州两个重要水库（红枫湖和百花湖）采集了未受扰动的沉积物样品性,分析了分层沉积物样品中的总氮,无机交换性氮和固定铵的含量及垂直剖面分布,研究表明,红枫湖和百花湖沉积物中具有较高的全氮含量,平均含量约为沉积物干重的0.36%～0.40%,其垂直分布在埋藏过程中受到成岩作用改造,沉积物交换性氮在沉积物中的赋存受到全氮含量和埋藏环境的双重控制,红枫湖和百花湖沉积物具有较强的吸持固定铵的能力,沉积物固定铵的绝对含量的平均值分别为434.05mg/kg和416.94mg/kg,分别占全氮的13.53%和12.53%。 相似文献
19.
湖泊湿地的水质净化效应——以太湖三山湿地为例 总被引：3，自引：2，他引：1
为了解湖泊湿地的水质净化效果,以太湖三山湿地为研究对象,综合利用遥感、GIS技术、现场水质监测、实验室分析和模型模拟等方法,分析三山湿地对污染物的拦截净化效果,进而探讨湖泊湿地对水体氮、磷污染物的削减渠道及其贡献率.结果表明三山湿地对太湖水体和三山岛生活污水均有明显净化效果.2014年三山湿地的总氮(TN)、总磷(TP)输入通量分别为549.45和19.4 t,通过水草打捞/收割分别去除20.99和4.52 t,湿地水体内TN、TP变化量分别为528.46和14.88 t,这部分营养盐输出途径包括沉积到底泥、降解转化、水体交换等.湿地的TN、TP拦截能力分别为2723.56和102.48 kg/(hm2·a).水生植物收割打捞与底泥疏浚是提高湿地水质净化能力的有效措施.水动力模拟结果显示,三山湿地建成后使附近水域水体流向发生变化,流速减小,对湿地内水质产生多方面的作用. 相似文献
20.
菹草、伊乐藻对沉积物磷形态及其上覆水水质的影响 总被引：3，自引：1，他引：2
采集武昌南湖湖水、沉积物进行沉水植物的盆栽试验,试验设置沉积物未施磷处理和施100mg/kg磷处理,分别对应沉积物低内源磷和高内源磷状态,同时种植菹草、伊乐藻,以研究沉积物中磷形态及上覆水水质的变化特点.研究从2007年9月15日开始,历时160d.结果表明,高内源磷沉积物处理后,上覆水中水溶性总磷含量在沉水植物的作用下明显降低;种植沉水植物可使水体总磷、总氮、叶绿素a含量显著降低,且伊乐藻对总磷的净化效果优于菹草;沉水植物对高内源磷沉积物的上覆水中叶绿素a的控制比对低内源磷条件下的效果更好;无论沉积物是否输入磷,在盆栽条件下,上覆水中叶绿素a随时间的变化均能较好地用一级动力学模型来描述;上覆水TDP、TP与沉积物中Ca_(10)-P之间有极显著正相关;种植菹草或伊乐藻的沉积物中Ca_(10)-P与上覆水中TDP和TP的相关系数分别为0.990(P≤0.01)和0.977(P≤0.05). 相似文献