首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
太湖水体中5种有机磷农药混合物生态风险评价   总被引:2,自引:0,他引:2  
有机磷农药是一类广泛分布于我国水环境中的污染物,即使在水体中的污染水平处于规定“安全标准”之下,其联合暴露产生的风险仍有可能威胁水生生态安全。采用基于浓度加和模型与生物敏感度分布曲线的混合物风险商法,评价了太湖水体中敌敌畏、对硫磷、甲基对硫磷、马拉硫磷和乐果5种有机磷农药混合物产生的生态风险。结果表明:2003~2004年期间3个不同时期太湖水体中5种有机磷农药的混合物生态风险商(RQm )均大于1,有机磷农药混合物在2003~2004年期间对太湖水生生物构成了一定威胁。  相似文献   

2.
应用物种敏感性分布法分析太湖及天目湖水体的生态风险   总被引:1,自引:0,他引:1  
采用物种敏感性分布法(SSDs法),应用水生生物急性和慢性毒性数据计算了31种污染物在水中和其中疏水物质在沉积物中的预测无效应浓度(PNECwater和PNECsed),通过收集以往报道的16种污染物在太湖和天目湖的环境浓度,用商值法求得物质的风险商并进行排序.结果发现:蒽、菲、萘、荧蒽、阿特拉津和马拉硫磷在太湖的梅梁湾和五里湖具有很大的生态风险;毒死蜱、三丁基锡氧化物和环己锡虽无环境浓度报道但很有可能具有风险.  相似文献   

3.
太湖流域水生态安全在维持长江流域生态安全格局中发挥重要作用。为阐明不同生态功能影响下太湖流域分区水生态安全状况,将太湖流域水生态功能分区与不同区域主导生态功能定位结合,构建基于主导生态功能定位的“压力-状态-服务”(PSS)模型并开展分区评估。结果表明,太湖流域整体生态安全形势为“较安全”和“基本安全”。太湖湖体生境状态因素最差,水质净化区、水源涵养区、水环境维持区和重要生境维持区的生境压力及生境状态为主要制约因素。太湖湖体Ⅱ-08、Ⅱ-10和Ⅲ-20水生态功能分区处于“不安全”水平,入湖河流污染负荷汇入影响突出。水环境维持区和重要生境维持区均受人类活动扰动影响较大。根据湖体与入湖河道水体、底泥氮磷浓度相关性研究结果,Ⅱ-03、Ⅲ-11、Ⅲ-12水生态功能分区水质与Ⅲ-20区域氮磷浓度关系密切,与总氮、总磷相关性显著(P>0.05)的入湖河道占比分别为50%、66.7%,应兼顾氮磷输入影响。Ⅲ-13和浙江省分别有100%、71.4%的入湖河道的TP浓度与湖体TP浓度相关性显著(P>0.05),应重点把控总磷输入风险,湖体总磷外源污染输入风险更大。入湖河道底泥中氮磷浓度较高,...  相似文献   

4.
精神活性物质是一类摄入人体后对中枢神经系统具有强烈兴奋或抑制作用的新型污染物,其在水环境中的存在可能对水生生物、水生态系统甚至人体健康产生潜在的危害。为评价太湖中精神活性物质的污染水平和生态风险,利用超高效液相色谱-质谱联用法检测了太湖19条入湖河流中13种典型精神活性物质的质量浓度和空间分布规律。结果表明,在太湖19条入湖河流中除苯甲酰牙子碱(BE)和去甲氯胺酮(NK)外,其余11种目标物均有检出,质量浓度范围为n.d.~43.2 ng·L~(-1)。其中麻黄碱(EPH)的检出率和中间浓度最高,分别为100%和11.0 ng·L~(-1);其次为甲基苯丙胺(METH),检出频率为58%,浓度中值为1.0 ng·L~(-1);苯丙胺(AMP)在东部湖区均未检出。大部分精神活性物质浓度水平较高的河流分布在竺山湾和西太湖,而海洛因(HR)的高值区主要在南太湖。运用风险熵方法对其进行风险评估,结果显示,太湖流域地表水中检出的13种精神活性物质的风险熵值均<0.1,生态风险较低,但其对水生生态系统的长期和综合风险值得关注。  相似文献   

5.
考虑物种权重校验保护太湖水生生物的铅基准   总被引:1,自引:0,他引:1  
孙雪华  孙成  刘红玲 《环境化学》2020,39(6):1578-1589
铅是一种有毒重金属元素,位列我国水中优先控制污染物"黑名单".我国水系众多,水生生物多样,研究保护区域水生生物的铅基准十分必要.太湖作为中国周边经济最发达、大中城市最密集且污染最严重的淡水湖泊之一,本研究选取8种太湖本土水生生物实验补充铅的急性毒性数据并两步外推得到慢性毒性数据.结合文献建立铅的本土毒性数据库,基于水体硬度对铅毒性的影响,建立硬度和毒性关系.考虑太湖生物区系和水质特征,采用物种权重敏感度分布方法,得到保护太湖水生生物铅的最大浓度基准值(CMC)和持续浓度基准值(CCC)值分别为50.04—58.87μg·L~(-1)和3.99—4.69μg·L~(-1);现行地表水铅的Ⅲ类标准限值(50μg·L~(-1))下受铅急性毒性和慢性毒性影响的生物比例分别为4.42%和23.00%.  相似文献   

6.
自COVID-19爆发以来,人类生活和经济受到很大负面影响,但同时疫情期间自然环境得到一定改善.为探究COVID-19管控对太湖重金属污染和水生生态风险的影响,将疫情期间(2021.6—2021.7)和爆发前(2019.9—2020.1)太湖重金属污染和水生生态风险进行对比分析,并通过PCAAPCS-MLR(主成分-绝对主因子分析-多元线性回归受体模型)对重金属进行定量源解析.结果表明,疫情期间太湖重金属污染水平和对水生生物的生态风险皆显著降低,降幅分别为39.9%—92.8%和0.19%—87.66%.整体水质优良比例提升了33.65%.重金属中受影响最大的元素为铜和铬.定量源解析结果表明,工业源对铜和铬的贡献率分别为79.75%和84.26%,疫情期间工业活动的减少是太湖重金属污染和生态风险降低的主要原因.为更好地管控太湖重金属污染和保护太湖水生生物,建议优先监管太湖周边电镀、冶炼和化学三大工业企业铜和铬的排放.  相似文献   

7.
太湖表层沉积物中多磷酸盐检出的环境意义   总被引:1,自引:0,他引:1  
在氮限制型富营养化湖泊中,沉积多磷酸盐(Poly-P)可以用来示踪营养盐磷的输入和湖泊的富营养化过程。太湖是一个典型的磷限制型富营养化湖泊,通过对太湖表层沉积物中总有机碳(TOC)、总氮(TN)、总磷(TP)、氢氧化钠可提取磷(NaOH-P)以及Poly-P的提取分析,初步探讨了太湖营养盐磷输入的历史记录,并揭示了该湖Poly-P的主要来源和保存机制。太湖Poly-P的质量浓度较低,变化范围为0.004~0.065mg·g-1。NaOH-P占TP组成的22%,是太湖沉积物总磷的主要组成部分之一。结果显示,在湖泊水体藻类生物量较大和NaOH-P是沉积物TP重要组成部分的磷限制型湖泊中,Poly-P也是沉积物磷汇组成的一个重要部分,同时还是一个可以反映由人为磷输入增大导致湖泊富营养化程度加剧的敏感指标。  相似文献   

8.
水动力条件对湖泊水体磷素质量浓度的影响   总被引:9,自引:2,他引:9  
以环形水槽为研究手段,利用其可控的流速及可模拟的无限长,解决了前人未解决的湖泊水体水动力难以真实模拟的难题,模拟研究了不同流速对湖泊(太湖)水体中磷素质量浓度的影响。研究表明,随着水体流速的变化,湖泊水体中TP质量浓度的变化呈现3个阶段,即下降期、上升期和突增期。从物理化学和泥沙起动理论两方面,结合水流对悬浮物和沉积物的作用,分析了各阶段产生的原因。文章认为下降期的产生是因为在低流速下,一部分磷被悬浮物的絮凝沉淀带走所引起;上升期的产生则是因为流速上升扰动沉积物,使其达到少量动状态所引起;突增期的产生则是因为流速导致了沉积物普遍动而产生的。在研究范围内,溶解性磷质量浓度与水体流速有着明显的正相关关系;而在低流速下,溶解性磷是TP的主要组成成分,其质量浓度的相对比例可高达87%。结合太湖的有关研究,文章认为这是水华现象产生的关键原因。  相似文献   

9.
多环芳烃(polycyclic aromatic hydrocarbons,PAHs)是环境中普遍存在的稠环类化合物,由于其对人体健康和生态环境产生较大危害,美国环保局将16种PAHs列为优先控制的污染物。PAHs也是太湖流域的主要污染物之一。作为华东地区的重要水系和水源地,研究太湖环境质量的变化对改善太湖流域水生生态系统和提高沿岸居民身体健康具有重要意义。论文研究了太湖胥口湾水域表层水和沉积物的PAHs。结果显示,表层水和沉积物的PAHs总浓度分别为7.2~83 ng·L~(-1)和66~620ng·g~(-1)干重;年均值为29 ng·L~(-1)和218 ng·g~(-1)干重;年均毒性当量浓度为2.4 ng·L~(-1)和28 ng·g~(-1)干重。沉积物中的主要污染物为荧蒽、芘和,影响毒性当量浓度的主要是苯并(a)芘和二苯并(a,h)蒽。4环PAHs在沉积物中占主要,其浓度百分比为44%~48%,而5环PAHs则占毒性当量总浓度的90%以上,说明其危害主要来自5环PAHs。PAHs特征化合物比值分析表明,胥口湾沉积物中PAHs主要来源于煤和木材燃烧,表层水大部分为燃烧和石油的混合来源。污染水平的时空变化特点为丰水期(8月)表层水PAHs浓度偏高,沉积物偏低。湖区和湖岸的PAHs浓度只在丰水期有显著差异,表层水PAHs浓度湖区高于湖岸,沉积物相反;其他时期湖区和湖岸PAHs浓度无显著差异。根据加拿大沉积物环境质量标准,胥口湾整体生态风险水平较低。从时空分布特征来看,个别生态风险较高的点主要分布在湖岸,5月平水期可能是沉积物中PAHs生态风险较高的频发期。  相似文献   

10.
太湖不同湖区生态系统健康评价方法研究   总被引:1,自引:0,他引:1  
基于长期的监测资料,计算了表征湖泊生态系统健康的系统能(Ex)、系统能结构(Exst)和生态缓冲容量(|β|)指标,以及湖泊营养状态指数(Its)。结果表明,太湖不同湖区生态系统健康状况差异明显,1998—2001年太湖典型湖区健康状况由好到差的相对顺序为:东太湖、贡湖和湖心区、梅梁湾、五里湖。在此基础上,提出了富营养化浅水湖泊生态系统健康指标阈值和湖泊系统能量健康指数(IEx)及其健康状况分级。经2002、2003年太湖不同湖区实测检验表明,所提出的湖泊系统能量健康指数及其健康状况分级适用于评价太湖不同湖区生态系统健康的区域分异状况。  相似文献   

11.
Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación  相似文献   

12.
Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.  相似文献   

13.
Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.  相似文献   

14.
The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.  相似文献   

15.
As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.  相似文献   

16.
Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.  相似文献   

17.
Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.  相似文献   

18.
Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.  相似文献   

19.
A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.  相似文献   

20.
Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号