奥奈达(Oneida)湖营养状态变化趋势及影响因素

【摘要】营养状态是湖泊生态系统的基本特征, 也常是全面认识湖泊生态系统的关键。为了解奥奈达湖营养状态演变, 根据1975-2012年5-10月奥奈达湖水体叶绿素a(Chl a)、总磷(TP)、透明度(SD)等指标, 采用修正的卡尔森营养状态指数法(TSIM), 计算了奥奈达湖营养状态指数, 分析了其营养状态演变规律及其影响因素。结果显示: 1975-2012年间奥奈达湖Chl a、TP、溶解氧(DO)和硝态氮(NO3--N)总体呈下降趋势, 下降幅度分别为2.6 µg·(L·10a)-1、1.5 µg·(L·10a)-1、0.3 mg·(L·10a)-1 和4.0 µg·(L·10a)-1; SD和水温(WT)呈上升趋势, 上升幅度分别为0.7 m·10a-1和0.5 ℃·10a-1; 溶解性活性磷(SRP)变化不明显; 此外Chl a、TP、SD、WT和DO均具明显季节变化。1975-2012年奥奈达湖的综合TSI呈下降趋势, 范围为37.8-51.3, 总体呈中营养状态; TSI的月均值也具明显季节变化; Chl a、TP以及斑马贻贝(Dreissena polymorpha)和斑驴贻贝(Dreissena rostriformis bugensis)的入侵是影响奥奈达湖营养状态的重要因素。该研究结果可为全面了解奥奈达湖营养状态演变提供参考。     

苏南地区湖泊群的富营养化状态比较及指标阈值判定分析

借助综合营养状态指数法、箱须图法以及拐点探测分析法,分析了苏南地区11个主要湖泊的富营养化特征以及各湖之间的差异性,并探讨湖泊由轻度富营养化向中度富营养化状态转换的相关指标阈值。结果显示苏南地区各湖泊的营养物水平存在明显的阶梯状特征,不同湖泊所处的富营养化阶段有所不同。典型封闭型湖泊水源地尚湖与傀儡湖水质最好,总体为Ⅱ—Ⅲ类,评价为中营养状态。典型过水性湖泊淀山湖与澄湖水质最差,TN和TP均劣于Ⅴ类,评价为中度富营养状态,其他湖泊属于轻度富营养化状态。基于拐点分析,提出苏南地区湖泊群富营养化状态由轻度向中度转变的指标阈值:COD Mn为4.7mg/L,NH3-N为1.0mg/L,TN为2.3mg/L,TP为0.125mg/L,Chl-a为25μg/L,透明度为50cm;尚湖和傀儡湖处于富营养化最轻的下游区,元荡和阳澄湖目前处于敏感的拐点区域,而淀山湖、澄湖、长荡湖等其他湖泊处于富营养化程度较重的上游区。苏南湖泊群的富营养化状态差异性主要是由不同人为干扰强度和水资源管理模式引起的,实现管理目标由资源利用向资源保护合理转变是解决富营养化问题的关键。     

三种浮游植物指示法在景观性河流水体营养状态评价中的应用

为探求三种浮游植物指示法在景观性河流水体营养状态评价中的应用是否合理,分别于2014年3月(枯水期)和5月(丰水期)在卫河新乡段进行为期两次的采样。选取3个采样点,从上游到下游依次编号1—3号,分别对3个采样点的浮游植物和相关理化因子进行分析。基于水体理化因子所得的综合营养状态指数(TSI)评价结果表明,卫河新乡段水质总体处于贫中-中富营养状态;丰水期比枯水期水体营养状态较低;同时下游2、3号位点在两次采样中的TSI值均高于1号样点,表明其富营养化程度更为严重。应用藻类污染指数、Shannon-Wiener指数和Q指数三种方法对水体进行评价,结果表明在景观性河流水体中,Shannon-Wiener指数的评价结果与TSI的评价结果相一致,适宜用于评价此类水体的营养状态。     

横岗水库富营养化特征分析

于2005年5月和11月调查了横岗水库的营养盐、叶绿素a(Chl.a)和浮游植物,对水库富营养化特征进行了分析。5月的总氮(TN)平均浓度为3.810mg?L-1,总磷(TP)平均浓度为0.172mg?L-1,Chl.a平均浓度为17.888mg?m-3,综合营养状态指数(TSIM)为73.3,该水库已达重度富营养化;11月份TSIM下降到55.6,处于轻度富营养化状态,TN和TP平均浓度分别下降到1.302mg?L-1和0.096mg?L-1,Chl.a平均浓度却上升到26.935mg?m-3,Chl.a浓度的上升与氨氮(NH3-N)和正磷(PO4-P)浓度上升以及浮游植物群落组成改变有关。从5月到11月,水库由蓝藻型富营养化水体变为绿藻型富营养化水体。5月浮游植物平均细胞密度高达2.75×108cells?L-1,优势种为美丽平裂藻和银灰平裂藻,其中平裂藻细胞数约占总细胞数的90%。11月浮游植物平均细胞密度降低到1.27×107cells?L-1,平裂藻的优势度下降,只占总细胞数的14.89%,绿藻成为主优势类群,其中栅藻是优势种之一,占总细胞数的11.52%。     

富营养化对白洋淀底栖-浮游耦合食物网结构和功能的影响

国际湖沼学的长期研究发现,一个完整的湖泊生态系统应包括底栖食物网和浮游食物网,而营养条件变化会显著改变浅水湖泊中底栖-浮游食物网的结构和功能。为了明晰富营养化对浅水湖泊底栖-浮游耦合食物网结构和功能的影响,以浅水草型湖泊——白洋淀为研究区,运用野外监测和ECOSIM与ECOPATH(Ew E)模型相结合方法,构建白洋淀底栖-浮游耦合食物网的概念模型,模拟1982—2011年间富营养化对白洋淀底栖路径和浮游路径的结构和功能影响:(1)野外监测的结果表明,从1999年至今白洋淀一直处于富营养化状态;(2)Ew E模型模拟结果表明1982—2006年,总生物量呈下降趋势,下降比例达66.38%;能流路径从以底栖路径为主转变为以浮游路径为主;(3)运用Pearson相关分析,结果表明:浮游植物与TN(r=0.67,P0.01)和TP(r=0.37,P0.05)呈显著正相关,而底栖藻类和大型沉水植物与TN(r=0.77,P0.01;r=0.67,P0.01)和TP(r=0.54,P0.01;r=0.36,P0.05)呈显著负相关。富营养化是白洋淀底栖初级和次级生产力向浮游初级和次级生产力转变的主要驱动力。采用科学的方法准确评估富营养化对湖泊底栖-浮游耦合食物网结构和功能的影响,可为湖泊生态系统管理提供技术和方法支持。     

湖泊生态系统弹性系数理论及其应用

在湖泊生态系统健康评价的基础上,分析城市湖泊营养状态的特殊性,论证得出响应型和非响应型湖泊的生态系统健康指数(EHI)与营养状态指数(TSI)近似呈二次函数关系.提出湖泊生态系统弹性系数,对生态系统健康指数(EHI)做出适当改进.改进后的生态系统健康指数(EHI′)能够更好地反映各类型湖泊的健康状态,完善了Xu等的EHI理论并扩展了其应用范围,是目前最为接近Costanza对HI定义的可量化计算的数学公式和方法,并成功用于厦门杏林湾生态系统健康评价.     

肇庆星湖浮游植物状况及其富营养化评价

研究了 1 996年 4月至 1 997年 7月肇庆星湖 5个子湖泊浮游植物种类和数量变化。在 1 996年 4月至 1 997年 7月 6次采样中 ,共鉴定出浮游植物 82种 ,其中绿藻门 37种 ,其次为硅藻和蓝藻门 ,优势种有鼓藻、栅藻、衣藻、席藻、直链藻、多甲藻和裸藻等。大多数采样点年平均浮游植物密度为 1 0 4 个 /L至 1 0 5个 /L,整个湖泊年平均密度为 4.2 8× 1 0 5个 /L。星湖各子湖泊全年的总氮、总磷含量分别低于 1 mg/L和 0 .1 mg/L ,以叶绿素 a、总氮、总磷、氨氮、COD和 BOD为参数的营养状态指数 (TLI) ,除波海湖外均小于 50。根据浮游植物种类和密度及综合营养状态指数评价结果 ,星湖的富营养化状况属于中营养化至富营养化之间 ,其中波海湖已达到富营养化水平 ,5个湖泊的富营养化程度由高至低依次为 :波海湖、仙女湖、里湖、青莲湖、中心湖。     

昆明小型城市湖泊叶绿素a浓度与硅藻群落的时空分布及主控因子

水体叶绿素a浓度(Chla)与硅藻群落特征是指示湖泊水质的常用生物指标。本研究于2017年3月—2019年12月调查了昆明市4个小型湖泊(云南师范大学校园内北潭、北湖、南湖、龙潭)的水体环境指标、Chla浓度和硅藻群落的季节变化。结果显示：4个湖泊水体总氮(TN)、总磷(TP)和Chla浓度均呈现明显的季节波动。其中，营养水平最高的南湖水体Chla含量显著高于其他3个湖泊，影响南湖Chla变化的主要因子是TN;而在其他3个水体中，水温的增加显著促进了Chla浓度的上升。水温和TN是4个湖泊水体Chla时空变化的主要驱动因子。北潭、南湖和龙潭的硅藻群落以浮游硅藻占优，水深最浅的北湖以底栖硅藻为主，表明水深影响了硅藻群落的浮游物种占比与优势属种。水深、TN、TP、透明度以及水温驱动了硅藻群落的时空变化，其中，水温是影响硅藻群落季节差异的主要因子，而TN和TP是导致同一季节湖泊间硅藻群落差异的主要因子。     

湖泊富营养化对轮虫群落结构及物种多样性的影响

2005年7月至2006年6月,我们对安徽省芜湖市境内5个湖泊中轮虫的群落结构及部分水质特征参数进行了调查,用相关加权综合营养状态指数(TLIc)评价了各湖泊的营养水平,分析了其中的轮虫群落结构、多样性指数及其与TLIC之间的关系。经鉴定,5个湖泊中共采集到轮虫79种,隶属18科31属;不同营养水平湖泊中出现的轮虫种类数有明显的差异(P<0.01)。除龙窝湖外,其余4个湖泊中的轮虫种类数与TLIC均呈显著负相关关系(r=–0.984,P<0.05)。湖泊水体的富营养化进程显著地提高了轮虫总密度和第一优势种的优势度,降低了轮虫群落的均匀度和物种多样性指数。     

太湖梅梁湾生态系统健康状况周年变化的评价研究

生态系统健康是生态学和环境管理方面一个新兴的多学科综合性研究领域。湖泊生态系统健康包含两个方面的内涵,满足人类社会合理要求和湖泊生态系统自我维持与更新的能力。湖泊生态系统健康评价是湖泊环境管理和生态系统调控的基础。运用Exergy、结构exergy和生态缓冲容量等指标来评价太湖梅梁湾湖区2001年生态系统健康的周年变化,其健康状况由好到坏依次为3～4>1～2>11～12>9～10>5～6>7～8月份。这和分别应用营养状态指数(TSI)和生物多样性指数(DI)进行评价的结果相似,表明运用Exergy、结构exergy和生态缓冲容量指标对湖泊生态系统健康状况进行评价的方法是可行的。     

江西省余江县水体营养状况分析

用营养状态指数法(TSI)对江西省红壤区余江县东塘、五湖、仙塘三个水库的水质状况进行综合评价,结果表明三个水体的水质状况均呈富营养态。在此基础上对三个水库的10项主要水化学指标进行主成分分析,表明亚硝态氮和氨氮对第一主成分的贡献最大,COD为第二主成分的主要贡献者;而且三个水库的水质受水中有机物含量的影响最大,这一结果与当地的农业结构密切相关。     

Lake eutrophication associated with geographic location,lake morphology and climate in China

Lake eutrophication is influenced by both anthropogenic and natural factors. Few studies have examined relationships between eutrophication parameters and natural factors at a large spatial scale. This study explored these relationships using data from 103 lakes across China. Eutrophication parameters including total nitrogen (TN), total phosphorus (TP), TN:TP ratio, chemical oxygen demand (COD_Mn), chlorophyll-a (Chl-a), Secchi depth (SD), and trophic state index (TSI) were collected for the period 2001–2005. Sixteen natural factors included three of geographic location, five of lake morphology, and eight of climate variables. Pearson correlation analysis showed that TP and TSI were negatively related to elevation, lake depth, and lake volume, and positively related to longitude. All eutrophication parameters, except for COD_Mn and Chl-a, showed no significant correlation with climate variables. Multiple regression analyses indicated that natural factors together accounted for 13–58% of the variance in eutrophication parameters. When the 103 study lakes were classified into different groups based on longitude and elevation, regression analyses demonstrated that natural factors explained more variance in TN, TP, COD_Mn, Chl-a, and TSI in western lakes than in eastern lakes. Lake depth, volume, elevation, and mean annual precipitation were the main predictors of eutrophication parameters for different lake groups. Although anthropogenic impacts such as point- and nonpoint-source pollution are considered as the main determinants of lake eutrophication, our results suggest that some natural factors that reflect lake buffer capacity to nutrient inputs can also play important roles in explaining the eutrophication status of Chinese lakes.     

Addressing the trophic status in urban ponds: An evaluation of current trophic state indexes

Ponds are generally understudied. Quality problems in urban freshwaters can arise from eutrophication, and trophic status classification gives information related to their ecological situation. Ponds may strongly differ from larger lakes for which most current trophic status classification methods have been developed. This paper seeks to compare and contrast the suitability of six trophic status indexes (TSI) and OECD trophic classifications system currently used to evaluate the eutrophication level of urban ponds in the Subtropical region. The trophic status was evaluated based on total phosphorus (TP), soluble reactive phosphorus (SRP), total nitrogen (TN) and phytoplankton chlorophyll a (Chl a) in 12 ponds placed in different cities from the Pampean region (Argentina), in the warm and cold seasons. Our results demonstrate that there was no relationship between pond size (0.08–2.45 ha) and trophic status. TSIs estimated with Chl a showed significant differences between seasons and the range oligotrophic-hypertrophic of trophism was encountered. Conversely, TSIs estimated with nutrient concentrations (TP, SRP, TN) did not. The pond's classification in trophic levels fell in the eutrophic-hypertrophic extreme, and only considering TN/TP broadened the trophic range. No relationship was encountered between Chl a and P; however, Chl a and TN/TP were positively correlated during the warm season. Lower trophic levels regarding TSI (Chl a) were generally associated with a dense floating-macrophyte cover. We suggest that the TSI considered should correspond to the latitudinal region in which the ponds are located. Our results indicate that it appears restrictive to consider only P contents in ponds to assess eutrophication. Under the proposed framework, the key issues for the study of pond trophic classification will be to include not only P but N concentrations and TN/TP. Also, phytoplankton Chl a concentration jointly with floating macrophytes biomass/coverage should be considered as diagnosis parameters.     

千岛湖水体叶绿素a与相关环境因子的多元分析

1999年1月至2000年12月对千岛湖水体的叶绿素a和理化因子进行了为期2年的逐月监测,对监测数据进行了多元逐步回归分析,找出与叶绿素a显著相关的环境因子,建立了多元回归方程．同时分析了叶绿素a含量的时空分布情况,并应用修正的卡尔森营养状态指数(TSI)对各监测点位的营养状态进行了排序．结果表明,湖区各监测点叶绿素a含量时空差异较大,新安江来水中叶绿素a含量变化较大．在5～30mg·m^-3之间,湖区内部监测点叶绿素a含量基本在5mg·m^-3以下,春季和秋季含量高于冬季和夏季含量．东南出水湖区大坝、密山和姥山点位的TSI<37。属贫营养型。其余湖区的TSI<53,为中营养型,与20世纪90年代中期的调查一致．湖区内部各监测点位的叶绿素a与理化因子关系比较复杂．在不同的监测点位。对藻类有显著影响的环境因子各有不同,但水温、总磷表现为正相关,透明度则表现为负相关．     

淀山湖富营养化过程的统计学特征

湖泊营养物输入及响应指标的统计学规律正在受到越来越广泛的关注。对淀山湖在不同富营养化阶段和近期总磷TP、总氮TN和叶绿素Chl a的频率分布以及TP-Chl a关系的经验方程进行了分析,结果表明:(1)淀山湖TP、TN和Chl a的平均浓度和离散程度随着湖泊富营养化程度的加剧而增加,其中以Chl a的增幅最大;(2)在富营养化条件下,即使营养物TP得到一定程度的控制,Chl a大于15μg/L的概率继续增加了20%以上。仅仅削减营养物的峰值,对降低湖泊初级生产力水平的贡献有限;(3)TP-Chl a对数回归方程的斜率随湖泊富营养化程度的升高而增加,由20世纪80年代的0.54增加到目前的2.46。淀山湖营养物输入及响应指标的统计学特征,可以用来表征水体富营养化程度,评价湖泊生态恢复的进程和效果,为湖泊营养物基准和标准的制定提供最为实际的统计学支持。     

Nitrogen and Phosphorus Limitation of Phytoplankton Growth in New Zealand Lakes: Implications for Eutrophication Control

We examine macronutrient limitation in New Zealand (NZ) lakes where, contrary to the phosphorus (P) only control paradigm, nitrogen (N) control is widely adopted to alleviate eutrophication. A review of published results of nutrient enrichment experiments showed that N more frequently limited lake productivity than P; however, stoichiometric analysis of a sample of 121 NZ lakes indicates that the majority (52.9%) of lakes have a mean ratio of total nitrogen (TN) to total phosphorus (TP) (by mass) indicative of potential P-limitation (>15:1), whereas only 14.0% of lakes have mean TN:TP indicative of potential N-limitation (<7:1). Comparison of TN, TP, and chlorophyll a data between 121 NZ lakes and 689 lakes in 15 European Union (EU) countries suggests that at the national scale, N has a greater role in determining lake productivity in NZ than in the EU. TN:TP is significantly lower in NZ lakes across all trophic states, a difference that is driven primarily by significantly lower in-lake TN concentrations at low trophic states and significantly higher TP concentrations at higher trophic states. The form of the TN:TP relationship differs between NZ and the EU countries, suggesting that lake nutrient sources and/or loss mechanisms differ between the two regions. Dual control of N and P should be the status quo for lacustrine eutrophication control in New Zealand and more effort is needed to reduce P inputs.     

Quantifying Relationships Among Phosphorus, Agriculture, and Lake Depth at an Inter-Regional Scale

To date, studies examining the impact of agriculture on freshwater systems have been spatially confined (that is, single drainage basin or regional level). Across regions, there are considerable differences in a number of factors, including geology, catchment morphometry, and hydrology that affect water quality. Given this heterogeneity, it is unknown whether agricultural activities have a pervasive impact on lake trophic state across large spatial scales. To address this issue, we tested whether the proportion of agricultural land in a catchment (% Agr) could explain a significant portion of the variation in lake water quality at a broad inter-regional scale. As shallow, productive systems have been shown to be particularly susceptible to eutrophication, we further investigated how lake mean depth modulates the relationship between % Agr and lake total phosphorus (TP) concentration. We applied both traditional meta-analytic techniques and more sophisticated linear mixed-effects models to a dataset of 358 temperate lakes that spanned an extensive spatial gradient (5°E to 73°W) to address these issues. With meta-analytical techniques we detected an across-study correlation between TP and % Agr of 0.53 (one-tailed P-value = 0.021). The across-study correlation coefficient between TP and mean depth was substantially lower (r = −0.38; P = 0.057). With linear mixed-effects modeling, we detected among-study variability, which arises from differences in pre-impact (background) lake trophic state and in the relationship between lake mean depth and lake TP. To our knowledge, this is the first quantitative synthesis that defines the influence of agriculture on lake water quality at such a broad spatial scale. Syntheses such as these are required to define the global relationship between agricultural land-use and water quality.     

湖北四湖泊营养类型与轮虫群落的关系

对湖北梁子湖水系不同营养类型(中营养型、富营养型)4个湖泊中轮虫的群落结构和物种多样性进行了周年研究,分析比较了不同营养类型湖泊的轮虫种类组成、分布、优势种组成、密度、生物量和多样性指数。结果表明：轮虫的种类数、物种多样性与营养水平呈负相关关系,轮虫密度大体上随营养水平提高而增大,富营养化引起轮虫空间异质性降低,受污染湖泊与非污染湖泊轮虫种类数、寡污性种类数及分布差异尤为明显。用多样性指数评价湖泊营养状态与TLIc方法一致。     

南太湖浮游植物特征及其富营养化评价

2008年8-9月对南太湖的浮游植物进行了调查,并对9个采样点水样进行了分析.结果表明:共有浮游植物47种,隶属于7门28属,其中蓝藻门 6属9种,绿藻门10属13种,硅藻门7属18种,裸藻门2属3种,隐藻门 1属2种,金藻门1种,甲藻门1种;南太湖浮游植物的密度为3.56×10~6～7.99×10~6 cells·L~(-1);浮游植物的Shannon-Weaver多样性指数为0.29～2.27,均匀度指数在多数位点<0.5,卡尔森营养状态指数(TSIM)均大于64;根据浮游植物的优势种组成、密度、多样性指数及富营养状态指数的评价结果说明南太湖处于富营养化阶段.

Abstract：

In August-September 2008, an investigation was made on the phytoplankton in south-ern Taihu Lake, and the water quality at nine sampling sites was analyzed. A total of 47 phyto-plankton species belonging to 28 genera and 7 phylums were collected, with 9 species of Cyano-phyta, 13 species of Chlorophyta, 18 species of Diatoms, 3 species of Euglenophyta, 2 species of Cryptophyta, 1 specie of Chrysophyta, and 1 specie of Dinophyta. The phytoplankton density was 3.56×10~6-7.99×10~6 cells·L~(-1), Shannon-Weaver index was 0. 29-2. 77, evenness was low-er than 0. 5, and trophic state index (TSIM) was higher than 64. Based on the evaluation of the dominant species composition, density, and Shannon-Weaver index of phytoplankton, and of the TSIM, the southern Taihu Lake was considered at the stage of eutrophication.