新疆艾比湖周边居民湿地生态系统健康保护意识调查分析

采用问卷调查的方法,试图真实反映艾比湖周边居民对艾比湖湿地生态系统退化的认知及对艾比湖湿地生态系统健康保护意识的强弱.结果表明：（1）艾比湖周边居民对湿地生态系统退化带来的危害有较为清晰地认识,99％被调查者意识到了艾比湖湿地生态系统退化对周边环境会带来不同程度的危害,78.2％调查对象认为艾比湖湿地生态系统的退化主要是由人类活动引发的,通过正规渠道获取艾比湖湿地生态系统退化信息不够通畅;（2）调查对象对艾比湖湿地生态系统退化情况持有较高的关注度,但支持度不高,85.6％的被调查者对退化湿地的生态恢复有支付意愿;（3）65.5％调查对象对艾比湖湿地生态恢复有信心,但对当地政府宣传和保护艾比湖湿地的力度满意度不高,因此政府部门还需进一步加强对艾比湖的宣传和保护力度.     

我国湿地补水生态补偿机制探析

近年来,由于全球气候变化及社会经济发展的双重影响,我国许多重要湿地面临着严重的缺水威胁.许多湿地的生态功能严重退化或丧失,湿地生态系统稳定性受到严重破坏,一部分国际重要湿地正面临被列入《湿地公约》“黑名单”的危险,湿地生态补水迫在眉睫.2011年中央政府工作报告中提出要“继续实施重大生态修复工程,加强重点生态功能区保护和管理……加强湿地保护与恢复”.     

鄱阳湖湿地生态系统退化的社会经济根源研究

鄱阳湖湿地生态系统是一个复杂、开放的交互系统。近些年,鄱阳湖湿地生态系统退化有加剧的趋势,其中有自然的原因,但更重要的是在社会经济发展过程中引起自然环境的破坏和生态规律的波动。人口持续增长、不合理的经济发展模式、湿地保护相关政策的缺失等都加剧了湿地生态系统的退化。加强湿地管理与保护、调整区域经济发展方式、构建环鄱阳湖生态经济区等措施,对保护和开发鄱阳湖湿地有重要的作用。     

加强赛里木湖生态环境保护保障区域生态安全

赛里木湖是我国西部干旱地区中的重要湿地,对维护北疆生态系统、调节北疆气候、涵养山地水源起着极其重要的作用。但目前区域生态环境呈现逐年退化态势,局部区域较为严重。通过实施湖泊生态保护项目,实现对区域内现有良好生态系统有效保护,对已有生态环境问题实施有效防治,促进赛里木湖生态保持良性发展。本文在综合赛里木湖区域生态环境现状与问题,以及目前区域生态保护与修复的主要措施和成效基础上,总结提出进一步做好赛里木湖生态环境保护确保区域生态安全的对策措施。     

浅谈城市湿地生态功能恢复问题与对策

城市的不断发展使不少城市湿地出现退化,表现为水污染严重、生物多样性下降、湿地面积萎缩等问题,使其原有的生态功能逐渐丧失。文章分析了城市湿地生态恢复亟待解决的问题,提出对退化的城市湿地进行生态恢复需要从多方面着手:在生态恢复之前,要设定合理的生态恢复目标;然后制定完善的工程规划,进行截污、管网改造等;重新构建其生物多样性,使城市湿地生态系统具有稳定性;最后,还需合理地较少人类活动的干扰对生态系统的影响。     

试析我国湿地的退化、保护与恢复

湿地是地球表层最具独特的生态系统和过渡性景观,是地球表层系统最重要的"物种基因库",又是人类重要的经济、文化、科学和生活资料库.世界保护大纲将湿地与森林、海洋一起并列为全球三大生态系统.20世纪70年代以来,全球性的湿地消失和退化危机引发了严重的生态环境和社会问题,直接威胁到区域、国家乃至全球的可持续发展.本文从湿地的界定开始,分析了我国湿地的退化、保护与恢复,相信在我国政府和人民的共同努力下,我国湿地一定会恢复往日的景象.     

1985—2016年安固里淖湖泊湿地生态系统稳态转变及对气候变化的响应

气候变化及人类活动严重影响着湿地的生态系统健康和可持续发展,进而对区域生态安全产生威胁. 以京津冀坝上地区典型内陆湖泊安固里淖湿地为例,结合1985—2016年的Landsat TM/ETM+影像数据生成MVWR指数(modified vegetation water ratio,修正化植被水体指数),基于“杯球”模型量化分析安固里淖湿地稳态转变与生态弹性,并进一步探究湿地稳态转变与生态弹性对气候变化的响应. 结果表明:①1985—2016年来安固里淖湿地于1995年、2004年发生了稳态转变,其RSI(regime shifts index,稳态转变指数)分别为0.973、2.108;1995年发生恢复性稳态转变,使得湿地水量增加、水域面积扩大,植被生长状态有所恢复;2004年发生退化性稳态转变,使得湿地进入严重受损状态,且2004年后湿地干涸的时期持续时间增加. ②就湿地稳态转变的空间分布而言,安固里淖湿地发生波动和剧烈波动的面积达9.26 km2,占比为17.81%,主要分布在湿地外围东部和南部,虽然湿地核心区域发生稳态转变的强度不及湿地外围东部和南部,但是在核心区小的转变仍能导致湿地生态系统的严重退化,使湿地整体发生稳态转变. ③1985—2016年安固里淖湿地生态系统弹性水平呈持续性下降,降幅达37.5%,从干涸中的恢复难度增加. ④气候要素中气温与降水对安固里淖湿地稳态转变均有影响,其中降水的影响更加显著,尤其是受前期降水影响明显,湿地稳态转变与长期的水量变化有关. 研究对湿地较长时间内的稳态转变及弹性状态变化定量化分析,以揭示湿地的退化过程,将生态系统弹性的持续下降作为湿地退化预警的一个信号,可为湿地的管理及修复提供理论依据和方法借鉴.      

洞庭湖区湿地生态系统存在的问题及其对策研究

洞庭湖是我国最大的淡水湖泊湿地景观生态系统之一,湿地资源丰富.由于泥沙淤积,洞庭湖区调蓄容积减少、洪水位不断抬升、江湖关系改变.在加重湖区的防洪负担、造成严重的洪涝灾害的同时,也降低了湖泊水体对各种污染物的稀释自净能力和水环境承载能力,导致湖泊湿地生态系统严重退化.本文分析了洞庭湖区湿地生态系统的功能,找出了导致洞庭湖区湿地生态系统退化的原因,并针对原因提出了一系列对策,以期恢复其原有功能.     

大庆市草原和湖泊生态保护建设研究

通过对大庆草甸草原和湖泊湿地发生发展自然生态过程的分析,以大庆生态环境的整体性特征为基础,提出草甸草原是大庆生态环境的基础,湖泊湿地是大庆生态环境的特色.以保护和恢复为主巩固草原生态基础地位,以生态重建为主突出湖泊湿地特色.对生态功能正常发挥的草原,以生态保护为主,对生态功能退化草原,以生态恢复为主.对油田生产区的草原,重视生态功能和景观效应.以生态重建为主突出湖泊湿地特色,通过地表水结构的调整增加生态系统的活力和生态服务功能.草甸草原和湖泊湿地的保护与利用要扬长补短、协同并进.     

把好湿地保护开发“平衡秤”

正今年是我国加入《湿地公约》22周年,湿地作为重要的自然资源和生态系统,具有不可替代的生态效益、经济效益和社会效益。然而,我国对湿地的保护与管理,在重视程度上,还不足以与当前建设"生态文明"的迫切要求相匹配,湿地面积减少、功能退化的趋势尚未得到根本遏制,湿地仍是最脆弱、最容易遭到侵占和破坏的生态系统。进一步重视和加强对我国有限湿地资源的保护,已是当务之急。要不断完善湿地保护规划,强化立法与考核,改变目前我国湿地保护零碎、分散的局面,在制度上规范湿地管理行为;理顺各方利益关系,平衡湿地保护与开发,妥善处理好     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.     

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.