气相色谱法测定土壤中BHCs和DDTs的残留

建立了土壤中六六六 (BHC )和滴滴涕 (DDT )异构体含量的气相色谱分析方法 ,样品以正己烷 丙酮利用超声波提取 ,提取液以层析柱净化 采用HP 1(Methylsiloxane )毛细管色谱柱分离样品 ,GC ECD检测BHC和DDT的残留量 ,方法的最小检测量为 1 5× 10 -13 — 1 6× 10 -12 g ;平均加标回收率为 92 6 %—99 2 % ;RSD为 2 2 %— 6 0 %     

天津污灌区土壤中多环芳烃的提取、净化和测定

研究了天津污灌区严重污染土壤中 1 6种多环芳烃的提取和测定方法 .考察了加速溶剂提取的提取条件、样品净化方法和GC MS测定条件 .结果表明 ,在 1 4 0℃用1∶1二氯甲烷和丙酮提取 5min ,硅胶柱净化后用GC MS测定可以得到很好的效果 .方法回收率在 5 7%— 1 4 0 %之间 ,检测限为 3 5× 1 0 - 4— 1 1× 1 0 - 3 mg·l- 1,且重现性较好 .天津代表性污灌水稻土中 1 6种PAHs的实测浓度为 0 0 7— 1 2 7mg·kg- 1.     

土壤中有机氯农药的多残留分析技术

本文建立了超声波提取 ,硅胶SPE柱净化 ,GC μECD检测土壤中α HCH ,β HCH ,γ HCH ,δ HCH ,HCB ,o p′ DDE ,aES,p p′ DDE ,Diel,Endrin ,p p′ DDD ,o p′ DDT ,p p′ DDT含量的方法 .对提取剂、洗脱剂和前处理步骤优化的结果表明 :体积比为 1∶2的丙酮 /石油醚是较好的提取剂和洗脱剂 ,方法加标回收率在 70 %— 1 1 0 %之间 ,检测限为0 0 5— 1ng·g- 1 .     

微波辅助萃取-气相色谱法检测裙带菜中的多氯联苯和有机氯农药残留

建立微波辅助萃取-气相色谱法同时检测裙带菜中多氯联苯和有机氯农药残留的方法.裙带菜风干、粉碎后,采用微波辅助萃取仪提取粗提液,经净化、脱酸、脱水、浓缩后,用气相色谱-电子捕获检测器进行分析检测.结果表明,本方法多氯联苯和有机氯农药的检出限分别在0.008—0.044 ng.g-1和0.029—0.273 ng.g-1之间,各组分线性相关系数均大于0.996,加标回收率为72%—131%,相对标准偏差在2%—16%之间(n=3).因此,本方法具有节省时间、减少污染、操作简单便捷等特点,可用于裙带菜等海洋藻类中多氯联苯和有机氯农药残留量的检测.     

叶类蔬菜有机氯农药残留测定过程中的提取和净化

用柱萃取法提取 ,气相色谱 电子捕获检测器 (GC ECD)测定蔬菜中的多种有机氯农药 .比较了不同提取溶剂对蔬菜中有机氯农药的提取效率 .就回收率而言 ,正己烷和丙酮 (V/V ,4∶1 ) >石油醚和丙酮 (V/V ,4∶1 ) >二氯甲烷和丙酮 (V/V ,4∶1 ) >纯正己烷 .用正己烷和丙酮作提取溶剂时 ,1 2种有机氯农药中有 1 0种的回收率在 80 %以上 ,变异系数在 1 %— 1 5 %之间 .不同固相萃取 (SPE)填料对有机氯农药的纯化效率为 :硅胶对目标物质的净化效率要高于硅藻土和氟罗里硅土 ,硅胶做填料时变异系数在 1 5 %以下 .因此 ,本实验认为用正己烷和丙酮 (V/V ,4∶1 )做提取剂、选择硅胶做填料能够对蔬菜中多种有机氯农药有较好的提取和净化效果 ,是一种较理想的蔬菜中有机氯农药的分析方法 .     

气溶胶水溶性有机物(WSOC)中二元羧酸的测定

提出了BF3 /丁醇酯化衍生反应 GC/MS分析大气气溶胶水溶性有机物 (WSOC)中二元羧酸 (乙二酸、丙二酸和丁二酸 )的测定方法 .其相应酯化产物乙二酸二丁酯、丙二酸二丁酯和丁二酸二丁酯的线性范围为 1× 1 0 - 5mol·l- 1— 1× 1 0 - 2 mol·l- 1,精密度分别为 1 6 7% ,3 0 4 %和 5 2 8% ;最低检测限分别为 1 9× 1 0 - 7mol·l- 1,1 1×1 0 - 7mol·l- 1和 1 2 5× 1 0 - 6mol·l- 1.并实测了北京市秋、冬两季乙二酸、丙二酸和丁二酸的平均浓度水平 ,分别为 4 44ng·m- 3 ,4 0ng·m- 3 ,30 2ng·m- 3 .     

水葫芦对污水中有机物的净化

本文系在室内模拟天津市南排污河水的流动状态和水质情况,研究水葫芦对污水的净化能力。研究结果表明,水葫芦对污水中的有机污染物木质素、合成洗涤剂有很强的净化力;对有机氯农药(γ-六六六、p、p′-DDE)也有一定净化功效。其中木质素的净化效率为97.40％,净化负荷为0.749g/kg(干)·d(五天,静态)。洗涤剂的净化效率为83.94—92.59％,净化负荷为0.062—0.111g/kg(干)·d(4—5天,静态);而在动态情况下,净化效率为72.37—85.02％,净化负荷1.98—4.15g/kg(干)·d。     

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 .     

采用一台气相色谱系统检测水质标准中四类有机化合物

本文采用1台Agilent 7890B气相色谱系统完成水中4类有机化合物的检测.水中4类有机化合物分别为:7种苯系物(BETX)包括苯、甲苯、乙苯、对二甲苯、间二甲苯、邻二甲苯、苯乙烯;5种挥发性卤代烃包括三氯甲烷、四氯化碳、三溴甲烷、三氯乙烯、四氯乙烯;8种有机氯农药包括α-六六六、β-六六六、γ-六六六、δ-六六六、p,p'-DDE、p,p'-DDD、o,p'-DDT、p,p'-DDT;7种有机磷农药包括敌敌畏、敌百虫、内吸磷、乐果、甲基对硫磷、马拉硫磷、对硫磷.优化顶空进样条件,采用微板流路分流器一次顶空进样同时完成水中苯系物及卤代烃分析.其中,对添加挥发性卤代烃(添加浓度分别为三氯甲烷4.00μg·L-1,四氯化碳2.00μg·L-1)及苯系物(添加浓度为400μg·L-1)的水样进行测定,各目标化合物的相对标准偏差RSD均小于2.5%.同时,对水中有机氯、有机磷农药进行分析,得到有机氯的相对标准偏差RSD范围为0.97%—3.7%,回收率范围为89.5%—104.9%.有机磷的相对标准偏差RSD范围为1.45%—2.94%,回收率范围为90.4%—98.8%.     

南京市城郊蔬菜生产基地有机氯农药残留特征

以网格法在南京市无公害蔬菜生产基地八卦洲采集70个土壤样品,用加速溶剂萃取、固相萃取柱净化后GC-μECD测定土壤中有机氯农药(α-HCH,β-HCH,γ-HCH和δ-HCH以及o,p'-DDT,p,p'-DDT,o,p'-DDE,p,p'-DDE 和p,p'-DDD)残留量.结果表明,土壤中有机氯农药残留总量在6.18～84.72 μg·kg-1之间,平均18.63 μg·kg-1.DDT残留量高于HCH,为3.36～74.19 μg·kg-1,平均12.61 μg·kg-1.土壤中HCH残留量为2.48～17.80 μg·kg-1,平均6.02 μg·kg-1.DDT同系物中以p,p'-DDE和p,p'-DDT为主,而HCH中δ-HCH含量较低,其他3种异构体含量水平相当.所有土样中DDT和HCH残留量均远远低于GB/T 18407 无公害蔬菜产地土壤标准限定值500 μg·kg-1,但大多数土样中DDT和HCH残留量远远高于荷兰无污染土壤标准.     

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.     

Importance of greater interdisciplinarity and geographic scope when tackling the driving forces behind biological invasions

Invasive non-native species are important drivers of ecosystem change, yet the driving forces of biological invasions themselves are poorly understood. Such information is essential to ensure policies focus on the most relevant drivers, and that future scenarios capture the full range of potential outcomes for invasive non-native species. I carried out a bibliometric analysis of articles published from 2000 to 2020 that address either invasive non-native species or biodiversity and ecosystem services and that also mention 1 or more drivers of ecosystem change. I examined 5 indirect drivers (demographic, economic, governance, sociocultural, and technological) and 6 direct drivers (climate change, invasive non-native species, land-use or sea-use change, natural hazards, pollution, and resource extraction). Using the Web of Science core collection of citation indexes, I undertook searches of article titles and keywords and retrieved 27,462 articles addressing invasive non-native species and 110,087 articles dealing with biodiversity or ecosystem services. Most research to date on biological invasions as well as on biodiversity and ecosystem services has focused on anthropogenic direct drivers of ecosystem change rather than indirect drivers. Yet currently, less than 18% of articles addressing biological invasions examined drivers of ecosystem change, a similar level to that found over 20 years ago for biodiversity or ecosystem services. Knowledge of the drivers of biological invasions is limited, emphasizes tractable drivers over those that require an interdisciplinary approach, and is biased toward developed economies. Drivers generally deemed important for biological invasions, such as governance and resource extraction, accounted for less than 2% of research effort. The absence of a systematic understanding of the forces that drive invasive non-native species and how they interact means that attempts to mitigate or forecast biological invasions are likely to fail. To address biological invasions requires a much better orientation of national and international research on drivers in relation to both their actual importance as well as their policy relevance.