淮河(江苏段)水体有机氯农药的污染水平

分别采集淮河丰水期和枯水期次表层水样 ,并用气相色谱 电子捕集检测器分析其中1 6种有机氯农药 .水体中总HCHs含量介于 1 1 1— 7 5 5ng·l- 1 ,总DDTs含量介于 4 45—78 87ng·l- 1 .水体中DDT/(DDE DDD)比值较大 ,表明此类化合物环境滞留期较长 ;六六六的两种异构体α/γ比值接近 1 ,表明近期可能有此类物质输入淮河水域 .有机氯农药的总量在 2 6 2 7— 1 2 4 39ng·l- 1 之间 .     

巢湖主要湖口水体和表层沉积物中有机氯农药的残留特征及风险评价

为了解巢湖湖口有机氯农药的污染状况,采集8个主要湖口的水体和沉积物样品,水样采用C18固相富集,沉积物用加速溶剂萃取仪提取后,萃取液浓缩、净化后,微量浓缩,用气相色谱-质谱联用仪分析测定21种有机氯农药.结果表明,研究区水体和表层沉积物中OCPs总量范围分别为40.1—87.7 ng·L~(-1)和11—26.3 ng·g~(-1),HCHs和DDTs为主要污染物,约占79.9%和65.1%.水体中OCPs含量从高到低依次为:南淝河十五里河双桥河派河裕溪河杭埠河大柘皋河小柘皋河;表层沉积物中OCPs含量从高到低依次为:十五里河双桥河南淝河裕溪河派河大柘皋河杭埠河小柘皋河.OCPs污染水平表现为城市污染控制型河流高于水土保持和面源污染控制型河流.根据组成物质成分比例关系进行源解析,发现水体和沉积物中HCHs和DDTs主要来自于早期农药蓄积残留,且降解环境以好氧为主.与国内其他湖泊对比,巢湖OCPs污染处于中等偏低水平.水体中HCHs、DDTs和六氯苯均未超过地表水环境质量标准,但表层沉积物中有机氯农药存在一定的生态风险.     

贵州百花湖水体中有机氯农药的残留及健康风险评价

为了研究贵州百花湖水体中有机氯农药(OCPs)对人体的潜在健康风险,在百花湖及其周边布设8个采样点分别采集水样,采用液液萃取-毛细管气相色谱法对OCPs的残留状况进行测定.结果显示,水样中11种有机氯的总含量范围为15.5～43.8ng·L-1,其中,BHCs和DDTs含量范围分别为3.2～14.6和1.2～7.8 ng·L-1.采用美国国家环境保护局(EPA)推荐的健康风险评价方法的评价结果表明,百花湖水体中OCPs的致癌风险和非致癌风险均低于国际辐射防护委员会(ICRP)推荐的最大可接受风险水平,表明百花湖水体中11种OCPs对人体健康风险处于较低水平.     

广州市农业土壤中六六六(HCHs)和滴滴涕(DDTs)的残留特征

采集了广州市农业土壤表层(0～20 cm)样品118个,采用气相色谱方法对土壤中六六六(HCHs)和滴滴涕(DDTs)进行分析,初步揭示了广州市土壤中有机氯农药的分布及残留情况,并做出潜在生态风险评价.研究结果表明:HCHs的检出率为95.8%,残留范围在ND～17.96 ng·g-1之间,平均值2.10 ng·g-1,DDT的检出率为92.4%,残留范围在ND～327.87 ng·g-1之间,平均值为1 8.97 ng·g-1.HCHs的4种异构体中,β-HCH质量分数最高,平均质量分数为0.86 ng·g-1,而p,p'-DDT是4种DDTs异构体中质量分数最高的,平均质量分数为11.89 ng·g-1.不同土壤利用类型中,耕地土壤中的有机氯农药残留量明显高于林地和果园地.与国内外部分地方和我国土壤环境质量标准相比,广州市农业土壤中DDTs和HCHs污染程度较低.     

太湖沉积物柱状样中有机氯农药的垂直分布特征

采用气相色谱质谱法测定了太湖沉积物柱状样品中有机氯农药(OCPs)含量,探讨了沉积柱中有机氯农药的垂直变化特征及可能的来源.研究结果表明:沉积柱中OCPs浓度为0.88—4.73 ng·g-1(干重),平均值为2.17 ng·g-1;DDTs、HCHs、六氯苯的残留量均较高,其中DDTs为0.10—1.32 ng·g-1,平均值为0.57 ng·g-1;HCHs的浓度为0.25—1.99 ng·g-1,平均值为0.65 ng·g-1;六氯苯为0.50—1.35 ng·g-1,平均值为0.92 ng·g-1.3个湖湾的沉积柱表层DDTs含量最高,有明显的表面富集现象,成分分析表明,太湖可能着存在着DDTs类物质的输入.     

乌鲁木齐市水磨河底泥及污灌区土壤中有机氯农药的分布

用GC-ECD定量测定了乌鲁木齐市水磨河底泥及污灌区土壤中有机氯农药的含量.结果表明:底泥样品中HCHs和DDTs的含量为0.107-111.69ng·g-1和0.476-66.512ng·g-1,有机氯农药总量为0.583-178.202ng·g-1;土壤中为0.194-6.974ng·g-1和0.520-10.438ng·g-1,有机氯农药总量为0.714-17.412ng·g-1.底泥中HCHs的α/γ比值约为4,底泥和土壤中DDT/(DDE DDD)的比值较大.     

北京市郊再生水灌区土壤有机氯农药垂向分布特征

在北京市郊再生水灌区采用正三角型布点法进行了3个钻孔的采样工作,钻孔间隔为1m,从表层开始每隔0.5m取一个样,3个钻孔共36组样品,同时采集钻孔附近的灌溉水及地下水,分别测试了土壤的理化参数及其土壤、灌溉水及地下水中9种有机氯农药的质量分数。测试结果表明：表层土壤是有机氯农药的主要残留层,表层土壤中检出的DDTs和BHCs质量分数较高,分别为2814.21ng·kg^-1和1130.41ng·kg^-1,但均符合土壤环境质量一级标准,残留污染程度较轻;其他层位以七氯和艾氏剂为主要检出物,最高质量分数分别为1286.19ng·kg^-1和781.23ng·kg^-1;其中艾氏剂未在表层土壤中检出;灌区内未检出的γ-BHC和（DDE＋DDD）/DDT的计算值为1.80,都说明近期内没有新污染源的输入;检出的有机氯农药在土壤剖面上的迁移能力有HEP〉ALD〉BHCs〉DDTs〉HCB,与地下水中检出的规律一致。     

黄浦江水相中有机氯农药的污染特征分析

本文研究了黄浦江水相中有机氯农药的浓度分布、组成特征和污染来源;分析黄浦江水体中有机氯农药(OCPs)含量的时空变化;在黄浦江水相样品中,除了甲氧氯在所有样品中均未检出外,其他20种有机氯农药在样品中均被检出,在所有水样中的OCPs浓度范围为0.29—44.7(中值2.19)ng·L~(-1).六六六(HCHs)是主要污染物,其次为滴滴涕(DDTs),浓度分别为0.13—38.3(中值0.92)ng·L~(-1)、0.03—3.28(中值0.63)ng·L~(-1).HCHs呈现出自上游至下游浓度逐渐升高的趋势,DDTs在上、下游无明显的空间分布规律.HCHs、DDTs的浓度均呈现夏季低、冬季高、春秋介于中间的季节性规律.     

珠江三角洲典型区域蔬菜地土壤中有机氯农药的污染特征——以东莞市为例

近年来珠江三角洲经济迅速发展的同时所带来的土壤有机氯农药污染问题备受关注,着重调查研究了东莞蔬菜地土壤中17种有机氯农药的污染特征.2002年10-12月采集蔬菜地土壤样品37个,利用气相色谱分析有机氯农药的含量.研究结果表明,东莞蔬菜地土壤样品中均检出有机氯,其中DDE与艾氏剂的检出率为100.0%;17种有机氯农药总含量(∑17OCPs)范围为2.47～82.23 ng·g-1,均值为22.53 ng·g-1.含有7个Cl取代基的有机氯农药即七氯与环氧七氯的含量均显著低于其他有机氯农药的含量;尽管东莞市蔬菜地土壤中DDTs的含量明显低于省内外其他地区蔬菜地土壤DDTs含量,但东莞蔬菜地土壤中有机氯农药主要以毒性较强的六氯代有机化合物为主,因此东莞蔬菜地土壤中有机氯农药污染状况不容忽视.     

珠江三角洲土壤中的有机氯农药的分布特征

为确定珠江三角洲土壤中有机氯农药的含量、来源以及组成特点,对珠江三角洲中心地带广州、佛山、东莞城市群的土壤进行了采样、处理以及气象色谱分析,测定了其中有机氯农药的含量:其中,三地土壤中HCHs的含量范围是0.19～42.3,均值4.42 ng·g-1,而且在四种HCHs的单体中β-HCH的含量在三地的土壤中分布最高;三地土壤中DDTs的含量范围是3.58～831,均值82.1 ng·g-1,而DDT/(DDD+DDE)的比值在一些样品中大于2甚至更高,说明近期内仍然存在着DDTs的使用和排放.广州东莞佛山三地土壤中有机氯农药的总量分别为205、46和105 t,构成了一个潜在的南海有机氯农药污染源.     

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     

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.     

Sequestration of cucurbitacin analogs by New and Old World chrysomelid leaf beetles in the tribe Luperini

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.     

Effects of Controlled Fire and Livestock Grazing on Bird Communities in East African Savannas

Abstract: In East Africa fire and grazing by wild and domestic ungulates maintain savannas, and pastoralists historically set fires and herded livestock through the use of temporary corrals called bomas. In recent decades traditional pastoral practices have declined, and this may be affecting biodiversity. We investigated the effects of prescribed fires and bomas on savanna bird communities in East Africa during the first and second dry seasons of the year (respectively before and after the rains that mark the onset of breeding for most birds). We compared abundance, richness, and community composition on 9‐ha burned plots, recently abandoned bomas, and control plots in the undisturbed matrix habitat over a 3‐year period. Generally, recently burned areas and abandoned bomas attracted greater densities of birds and had different community assemblages than the surrounding matrix. The effects of disturbances were influenced by interactions between primary productivity, represented by the normalized difference vegetation index, and time. Bird densities were highest and a greater proportion of species was observed on burned plots in the months following the fires. Drought conditions equalized bird densities across treatments within 1 year, and individuals from a greater proportion of species were more commonly observed on abandoned bomas. Yearly fluctuations in abundance were less pronounced on bomas than on burns, which indicate that although fire may benefit birds in the short term, bomas may have a more‐lasting positive effect and provide resources during droughts. Several Palearctic migrants were attracted to burned plots regardless of rainfall, which indicates continued fire suppression may threaten their already‐declining populations. Most notably, the paucity of birds observed on the controls suggests that the current structure of the matrix developed as a result of fire suppression. Traditional pastoralism appears critical to the maintenance of avian diversity in these savannas.     

What Every Conservation Biologist Should Know about Economic Theory

Abstract: The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self‐referential and narrowly rational way and that production can be described as a self‐contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self‐centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement.     

Effects of Coffee Management on Deforestation Rates and Forest Integrity

Knowledge about how forest margins are utilized can be crucial for a general understanding of changes in forest cover, forest structure, and biodiversity across landscapes. We studied forest‐agriculture transitions in southwestern Ethiopia and hypothesized that the presence of coffee (Coffea arabica)decreases deforestation rates because of coffee's importance to local economies and its widespread occurrence in forests and forest margins. Using satellite images and elevation data, we compared changes in forest cover over 37 years (1973–2010) across elevations in 2 forest‐agriculture mosaic landscapes (1100 km² around Bonga and 3000 km² in Goma‐Gera). In the field in the Bonga area, we determined coffee cover and forest structure in 40 forest margins that differed in time since deforestation. Both the absolute and relative deforestation rates were lower at coffee‐growing elevations compared with at higher elevations (?10/20% vs. ?40/50% comparing relative rates at 1800 m asl and 2300–2500 m asl, respectively). Within the coffee‐growing elevation, the proportion of sites with high coffee cover (>20%) was significantly higher in stable margins (42% of sites that had been in the same location for the entire period) than in recently changed margins (0% of sites where expansion of annual crops had changed the margin). Disturbance level and forest structure did not differ between sites with 30% or 3% coffee. However, a growing body of literature on gradients of coffee management in Ethiopia reports coffee's negative effects on abundances of forest‐specialist species. Even if the presence of coffee slows down the conversion of forest to annual‐crop agriculture, there is a risk that an intensification of coffee management will still threaten forest biodiversity, including the genetic diversity of wild coffee. Conservation policy for Ethiopian forests thus needs to develop strategies that acknowledge that forests without coffee production may have higher deforestation risks than forests with coffee production and that forests with coffee production often have lower biodiversity value. Efectos de la Administración Cafetalera sobre las Tasas de Deforestación y la Integridad de los Bosques     

Globalization of the Cashmere Market and the Decline of Large Mammals in Central Asia

As drivers of terrestrial ecosystems, humans have replaced large carnivores in most areas, and human influence not only exerts striking ecological pressures on biodiversity at local scales but also has indirect effects in distant corners of the world. We suggest that the multibillion dollar cashmere industry creates economic motivations that link western fashion preferences for cashmere to land use in Central Asia. This penchant for stylish clothing, in turn, encourages herders to increase livestock production which affects persistence of over 6 endangered large mammals in these remote, arid ecosystems. We hypothesized that global trade in cashmere has strong negative effects on native large mammals of deserts and grassland where cashmere‐producing goats are raised. We used time series data, ecological snapshots of the biomass of native and domestic ungulates, and ecologically and behaviorally based fieldwork to test our hypothesis. In Mongolia increases in domestic goat production were associated with a 3‐fold increase in local profits for herders coexisting with endangered saiga (Saiga tatarica).That increasing domestic grazing pressure carries fitness consequences was inferred on the basis of an approximately 4‐fold difference in juvenile recruitment among blue sheep (Pseudois nayaur)in trans‐Himalayan India. Across 7 study areas in Mongolia, India, and China's Tibetan Plateau, native ungulate biomass is now <5% that of domestic species. Such trends suggest ecosystem degradation and decreased capacity for the persistence of native species, including at least 8 Asian endemic species: saiga, chiru (Pantholops hodgsoni), Bactrian camel (Camelus bactrianus), snow leopard(Panthera uncia), khulan(Equus hemionus), kiang (E. kiang), takhi (E. przewalski), and wild yak (Bos mutus). Our results suggest striking yet indirect and unintended actions that link trophic‐level effects to markets induced by the trade for cashmere. Globalización del Mercado de Cachemira y la Declinación de Mamíferos Mayores en Asia Central     

The lichen-rich coastal heath vegetation on the isle of Anholt, Denmark — conservation and management

The high conservational value of the lichen-rich vegetation and landscape of the marine foreland Ørkenen on the isle of Anholt is treated from a Danish as well as a European perspective. The sensitivity of the lichen-rich vegetation to physical disturbance is emphasized. The impact of invasive species such asPinus mugo as well as the effect of atmospheric deposition of nutrients on the heaths at Anholt is described. Considerations related to the development of a management plan for Ørkenen are presented.     

Behavior and ecology of Old World Luperini beetles of the genusAulacophora (Coleoptera: Chrysomelidae)

Summary The attraction of Old World leaf beetles in the genusAulacophora to kairomones and parakairomones which are effective lures for New WorldDiabrotica andAcalymma were investigated. Beetles captured on sticky traps baited with single and multicomponent lures were no different from the control traps for two species ofAulacophora. Yellow colored traps and squash blossoms are attractive toAulacophora beetles which detect sub-microgram quantities of cucurbitacins on silica gel. Leaf feeding behavior and flight activity data are correlated with varietal preference of threeAulacophora species. The common response byDiabrotica andAulacophora to cucurbitacins reinforces the two groups' coevolutionary association with the Cucurbitaceae. The apparent lack of a common response toCucurbita blossom volatiles suggests recent evolutionary pathways are substantially different for these two groups of beetles.     

Use of stochastic patch occupancy models in the California red-legged frog for Bayesian inference regarding past events and future persistence

Assessing causes of population decline is critically important to management of threatened species. Stochastic patch occupancy models (SPOMs) are popular tools for examining spatial and temporal dynamics of populations when presence–absence data in multiple habitat patches are available. We developed a Bayesian Markov chain method that extends existing SPOMs by focusing on past environmental changes that may have altered occupancy patterns prior to the beginning of data collection. Using occupancy data from 3 creeks, we applied the method to assess 2 hypothesized causes of population decline—in situ die-off and residual impact of past source population loss—in the California red-legged frog. Despite having no data for the 20–30 years between the hypothetical event leading to population decline and the first data collected, we were able to discriminate among hypotheses, finding evidence that in situ die-off increased in 2 of the creeks. Although the creeks had comparable numbers of occupied segments, owing to different extinction–colonization dynamics, our model predicted an 8-fold difference in persistence probabilities of their populations to 2030. Adding a source population led to a greater predicted persistence probability than did decreasing the in situ die-off, emphasizing that reversing the deleterious impacts of a disturbance may not be the most efficient management strategy. We expect our method will be useful for studying dynamics and evaluating management strategies of many species.