汞矿区大气汞的流通量与汞干湿沉降研究

应用ＦｌｕｘＣｈａｍｂｅｒ技术评价汞矿,矿渣及附近土壤表面汞的流通量,表明,土壤表面汞的流通量平均为１７３．５ｎｇ．ｈ＾－１．ｍ＾－２,矿均为２３６．６ｎｇ．ｈ＾－１．ｍ＾－２,原矿平均为７０ｎｇ．ｈ＾－１．ｍ＾－２。     

改性绿茶对汞的吸附研究——汞的形态分析

试验了用改性绿茶分离，冷原子吸收光谱法测定无机汞，烷基汞和苯基汞的条件。在ｐＨ５的溶液中吸附无机汞，与有机汞分离；在ｐＨ１的溶液中吸附有机汞，然后分别以１．５，３．０和６．０ｍｏｌ·１＾－１盐酸解吸无机汞，烷基汞和苯基汞，用冷原子吸收光谱法测定汞，探讨了吸附机理，分析了牡蛎和水样中汞的形态。     

一种新的真空冷原子吸收法测定汞

本文建立了真空冷原子吸收光谱技术测定汞的一种方法。在负压下用ＮａＢＨ４将酸性溶液中Ｈｇ（Ⅱ）离子还原成为金属汞。在室温下使用真空泵将基态汞原子直接吸入到真空石英炉内。本法给出了改善的灵敏度,检出限（３σ）是０．０６ｎｇ。重复１０次测定０．５ｎｇ汞,方法的相对标准偏差是３．０％,将本法应用到测定水系沉积物标准样品中汞的含量,分析结果是令人满意的。     

蔬菜和水果中残留硫双威的气相色谱分析

本文提出了一种快速、高效提取净化蔬菜、水果中残留硫双威的前处理方法和用火焰光度检测的气相色谱法。该法的最低检出浓度为０．０４ｍｇ·ｋｇ＾－１，在蔬菜，水果中的平均加标回收率分别为９３．０－１０６．７％和９４．５－１０４．２％，变异系数分别为２．５７－６．０５％和２．７４－５．８３％。     

大气汞氧化还原过程与机制的计算化学研究进展

大气中汞的氧化还原反应对于其全球生物地球化学循环起着极其重要的作用,它促进了汞在全球范围内的扩散.汞主要以气态元素汞的形态释放到大气中,并经历复杂的均相和非均相化学反应,被氧化为活性气态汞和颗粒态汞;同时,活性气态汞也可经过光致还原反应光解生成气态元素汞.计算化学是一种基于理论方法利用计算软件来对化学现象和本质进行解释...     

贵州省务川汞矿区汞污染的初步研究

对贵州省务川汞矿区的大气、地表水和土壤中汞污染的调查表明,务川汞矿区大气汞浓度为7-40000 ng·m-3,超出正常大气汞浓度1-4个数量级.地表水总汞为43-2100 ng·l-1,远高于对照区(15-29 ng·l-1);活性汞、溶解态汞和颗粒态汞含量也显著高于对照区,颗粒态汞是地表水汞迁移的主要方式.土壤总汞含量为1.3-360 mg·kg-1,远高于对照区土壤总汞含量(O.22-0.39 mg·kg-1),土壤剖面汞含量的垂向递减反映了大气汞的沉降是土壤汞的重要来源之一;同一地点不同土地利用类型的土壤,一般为稻田总汞含量高于菜地和玉米地;土壤pH值和有机质影响着土壤中汞的迁移和富集.     

贵州万山汞矿地区耐汞野生植物研究

在贵州万山地区废弃汞矿堆和矿山附近,受长期高剂量汞暴露的影响经过的自然选择,该地区出现了一些能耐受汞毒性的生态型植物。对汞耐受及汞富集植物的筛选对于汞污染土壤的植物修复具有一定的现实意义。通过对万山梅子溪地区汞污染土壤及汞耐受植物采样调查发现,该区域采样土壤中汞的含量均在50 mg·kg-1以上,达到重度汞污染水平。对该地区野生植物的采样分析发现,蔷薇科植物悬钩子不仅数量较多,单株植物生物量较大,表现出很强的耐汞毒性的能力,而且植株内可以很大程度地富集汞,在其植株中汞的含量可达20 mg·kg-1左右,属于汞富集植物,另外发现野蒿对汞也具有较强的富集能力,其植株中汞的含量可达10 mg·kg-1以上。该类型植物的发现将为植物的汞耐受以及汞富集机理研究提供新的素材,为汞污染土壤的植物修复技术提供新的植物类型,也为进一步开发汞污染土壤处理技术提供了一种可能。     

甲基汞与总汞在低硫煤洗选过程中的脱除行为

以焦作市演马洗煤厂进料原煤及洗选产品为研究对象,对低硫煤中总汞与甲基汞含量进行测定,初步探讨了洗选过程中总汞与甲基汞的迁移规律、脱除效果及质量平衡.研究发现,原煤及洗选产品中总汞含量0.128-0.392 mg·kg-1;值得注意的是,原煤及洗选产品中均检出了甲基汞,含量为33.58-56.75 ng·kg-1.经过洗选,总汞在精煤中得到脱除,脱除率为24.68％,在筛末煤、中煤、副产品中被富集;甲基汞在大部分洗选产品中含量均有所降低,整体呈脱除趋势,脱除率为-3.46％-38.78％.该低硫煤中总汞与灰分显著正相关,与硫分呈负相关,在洗选过程中受灰分影响较大;甲基汞与灰分、硫分均极低相关,无明显的迁移规律.煤炭洗选前后的总汞质量平衡为108.06％,甲基汞质量平衡为80.08％.该低硫煤通过洗选,约60.55％的总汞和35.37％的甲基汞随筛末煤、中煤与副产品的排出而被去除,故需留意部分洗煤产品和副产品的存放与使用,避免可能对环境造成的汞污染问题.     

桂林市菜地土壤-蔬菜汞污染研究和评价

对桂林市近郊8个不同片区蔬菜产地的118个土壤样品和71个蔬菜样品中汞的含量水平进行了调查和分析。运用单因子污染指数法评价了菜地土壤一蔬菜中汞的污染现状。研究表明，桂林市及近郊菜地土壤和蔬菜已受到不同程度的汞污染，全市各片区菜地土壤汞含量平均值为0．098-0．523mg／kg，以国家土壤环境质量标准二级标准评价，土壤平均污染指数在0．33-1．74范围内，属非污染或轻污染状态，除穿山南片和纸马铺外，其余采样点均有样本超过国家二级标准，其中七星公园东北片的土壤汞超标率较高，达71．4％，污染情况比较均一；虞山桥东南岸土壤汞超标率较低，为33．3％，但土壤汞含量变异较大，说明污染情况变化大。全市各片区老菜的汞含量平均值为0．0625-0．128mg／kg，为国家标准GB2762—1994规定蔬菜汞含量(0．01mg／kg)的6．25—12．8倍，超标率已达100％。实验还发现，蔬菜中的汞含量与土壤中的汞含量具有显著的相关性，且蔬菜汞的大部分分布于地上部可食部分。分析了菜地土壤汞污染的主要原因，可能与使用含汞农药和生活垃圾肥有关。     

树脂富集-冷原子吸收法测定天然水中痕量无机汞和有机汞

3926B型巯基树脂性能稳定,能多次再生使用,配合冷原子吸收法适于富集测定饮用水及天然水中溶解态痕量无机汞和有机汞。1—4l水样调至pH2.5,以15ml/min流速通过装有1g树脂的交换柱。用5％硫脲酸性溶液,以0.4ml/min流速淋洗。收集25—50ml淋洗液,取一部分加入10ml 5％硫脲溶液和10ml 20％氢氧化钠,测无机汞(加10％氯化亚锡2ml)和总汞(加含6000ppm镉的10％氯化亚锡2ml)。差减求出有机汞。本法八次富集测定重蒸去离子水,未检出有机汞,无机汞含量在9.2—11.8ppt范围,相对标准偏差6.35％。对重蒸去离子水、自来水、雨水和河水富集测定,检出最低平均含无机汞10ppt,有机汞2ppt。有机汞回收率河水为84％,其余在91％以上,相对误差小于4％。若以10l水样富集,将能测定0.2ppt汞。     

Representation of the world's biophysical conditions by the global protected area network

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.     

Quantitative composition of the defensive secretion ofBledius species (Coleoptera: Staphylinidae: Oxytelinae) is adapted to naturally occurring predators

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.     

Democracy versus development: New urban debates

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.     

Achieving Open Access to Conservation Science

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     

A framework to measure the wildness of managed large vertebrate populations

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.     

Sexual Predators,Energy Development,and Conservation in Greater Yellowstone

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.     

Comparison of the insecticidal effects of water extracted and intact aromatic plants onAcanthoscelides obtectus,a bruchid beetle pest of kidney beans

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.     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

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.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

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.