阴/非离子表面活性剂强化微米Cu/Fe对水及土壤泥浆中有机氯农药的降解

选择氯丹、硫丹和灭蚁灵为目标污染物,以实际污染场地土壤为对象,研究了表面活性剂强化微米Cu/Fe双金属对水和土壤泥浆中有机氯农药的降解效果。结果表明,非离子表面活性剂Triton X-100(TX-100)强化效果优于阴离子的十二烷基磺酸钠(SDS)。TX-100强化微米Cu/Fe体系能实现水中有机氯农药的快速高效降解,最佳TX-100浓度为0.1 mmol·L-1。处理12 h后,γ-氯丹、硫丹和α-氯丹的降解率接近100%,灭蚁灵的降解率达到85.2%。对于土壤泥浆体系,偏酸性p H值对微米Cu/Fe的还原活性有重要作用。加入TX-100显著促进了微米Cu/Fe双金属对土壤中有机氯农药的还原降解(P0.05)。Cu负载量的提高增强了污染物的降解去除效果。当m(土)∶V(水)为1∶5、土中Fe投加量w为10%、Cu负载量为5.0%、TX-100浓度为5.0 mmol·L-1、p H值为4~5时,处理72 h后,γ-氯丹、硫丹、α-氯丹和灭蚁灵的降解率分别为83.5%、68.1%、86.8%和70.1%。TX-100强化微米Cu/Fe双金属还原降解是一种有效的有机氯农药污染土壤修复技术。     

驯化的活性污泥强化降解土壤中氯酚的研究

以接种驯化的活性污泥为生物强化手段,在小型生物泥浆反应器中,研究了受氯酚污染土壤的修复情况.考查了添加驯化活性污泥对土壤中氯酚降解的强化效果,并对土壤中邻氯苯酚(2-CP)、对氯苯酚(4-CP)和2,4-二氯酚(2,4-DCP)在单一污染体系中的降解情况进行了研究.结果表明,在生物泥浆反应器中添加用邻氯苯酚(2-CP)驯化的活性污泥可以明显地促进土壤泥浆中2-CP的降解,是一种有效的强化手段.该方法对土壤中的4-CP和2,4-DCP也有较好的降解效果,对三种氯酚的降解速率由大到小的顺序为2-CP,4-CP,2,4-DCP.反应结束时,泥浆体系中剩余的氯酚基本都残留在土壤中,固液分离后的水相可以直接排放或者在土壤修复过程中循环利用.     

生物炭降低土壤中2,4,6-TCP有效性能力的评估

2,4,6-三氯苯酚(2,4,6-TCP)作为杀菌剂、除草剂、防腐剂被广泛应用于农业,土壤中2,4,6-TCP污染引起了人们的关注。采用批平衡实验研究了2,4,6-TCP在4种土壤(乌栅土、红壤、黑土、潮土)中的淋溶迁移性,以及在生物炭和土壤中的吸附效果。结果表明,2,4,6-TCP在土壤中淋溶迁移性大小顺序为潮土乌栅土黑土红壤。2,4,6-TCP在4种土壤中吸附等温线采用Freundlich方程拟合最佳,在乌栅土、红壤、黑土和潮土中的吸附常数Kf分别为0.775 9、75.01、100.3和0.904 7。红壤和黑土对2,4,6-TCP有很强的吸附能力,吸附曲线呈较为明显的非线性,可能为表面吸附;而乌栅土和潮土的吸附能力很差,吸附曲线呈较为明显的线性,可能为分配作用。由不同原料(稻杆、果壳、椰壳)制备的生物炭对2,4,6-TCP吸附量有明显的差异,其中椰壳生物炭吸附效果最好。添加椰壳生物炭后,土壤对2,4,6-TCP吸附能力增强,生物炭在土壤-生物炭混合体系吸附2,4,6-TCP中起主导作用,且受土壤类型的影响。并通过模型评估生物炭修复2,4,6-TCP污染土壤的可行性,其中椰壳生物炭修复效率最高,去除土壤中50%的2,4,6-TCP所需椰壳生物炭用量为2 675 kg·hm-2。研究结果为生物炭降低土壤中2,4,6-TCP有效性的评估和修复2,4,6-TCP污染土壤提供了科学依据。     

假单胞菌AEBL3对土壤中呋喃丹的生物降解

从农药污染的农田土壤中分离到一株假单胞菌AEBL3，该菌能够以呋喃丹为唯一的碳源和氮源生长。使用AEBL3作为生物强化剂对模拟呋喃丹污染的土壤环境进行了生物修复试验。结果表明，接种AEBL3能够明显增加土壤中呋喃丹的降解率。降解菌AEBL3在土壤中具有一定的移动性，当从土壤表层加菌时，对0-7cm深土层中的呋喃丹都有很好的降解效果。在各种投加方式的比较中，以投加降解菌原液修复效果最好，缓冲液悬浮的菌细胞次之，砂粒混合物的效果最差。16S rRNA的变性梯度电泳(DGGE)结果揭示了生物修复过程中土壤微生物菌群结构中的动态变化。     

2种甲氧基丙烯酸酯类杀菌剂在土壤中的降解吸附特性及对地下水的影响

采用室内模拟试验,以江西红壤、东北黑土和太湖水稻土为代表性土壤,研究了啶氧菌酯和肟菌酯在土壤中的降解、吸附特性,并利用地下水污染指数(GUS)分析了其对地下水污染的影响。结果表明,杀菌剂的降解速率因含有的官能团不同而差异较大,常温、好氧条件下,啶氧菌酯在江西红壤和东北黑土中为较难降解性,在太湖水稻土中为难降解性,肟菌酯在上述3种土壤中均为易降解性;常温、积水厌气条件下,啶氧菌酯在江西红壤、太湖水稻土和东北黑土中均为中等降解性,肟菌酯在3种土壤中均为易降解性。积水厌气条件有利于啶氧菌酯和肟菌酯的降解,厌氧微生物是影响甲氧基丙烯酸酯类杀菌剂降解的重要因素。啶氧菌酯在江西红壤、东北黑土和太湖水稻土中的吸附均较好地符合Freundlich吸附等温方程,土壤有机碳分配系数(Koc)分别为811、613和926,属较难吸附等级,土壤有机质含量是影响啶氧菌酯在土壤中吸附性能的主要因素。采用高效液相色谱法估算可知,肟菌酯Koc20 000,属易吸附等级。啶氧菌酯在3种土壤中的GUS值介于1.8~2.8,具有一定的淋溶性,对地下水具有一定的潜在污染风险;肟菌酯在3种土壤中的GUS值均1.8,不淋溶,对地下水的潜在污染风险较小。     

强化生物堆法修复多环芳烃污染土壤的初步研究

以多环芳烃(PAHs)污染场地土壤为研究对象,研究了不同工艺条件的生物堆反应器中PAHs降解效果,并通过对PAHs高效降解混菌的筛选富集,探讨菌液投加对生物堆技术处理PAHs污染土壤的强化修复作用效能。结果表明,生物堆运行过程中土壤pH和含水率基本保持稳定,总PAHs在9 d内快速降解,降解率达到80%以上,之后基本不变;生物堆在短期内(9 d)对低分子质量(2～3环)PAHs具有较高降解效率,达到91%;但中、高分子质量(4～6环)PAHs的降解效率只有60%,降解中、高分子质量PAHs可能需要更长时间。在试验期内添加表面活性剂、通风和投加PAHs降解菌液对总PAHs降解率均没有显著提升,但添加菌液后土壤脱氢酶活性大幅升高,投加菌液的3#和4#处理在80 d时脱氢酶活性较41 d时分别增加约7倍和9倍。PAHs降解菌液可能对PAHs降解中间产物的进一步矿化起到显著促进作用。添加表面活性剂并通风处理的脱氢酶活性更高,达到10 740μg·g~(-1)·h~(-1),说明其对中间产物降解的促进作用更大。该研究验证了生物堆技术在PAHs污染土壤修复中的有效性,并对比了不同强化措施对修复效果的影响,为该技术在PAHs污染场地修复中的应用提供了重要数据支撑。     

外源降解菌对黄麻根区净化能力的生物强化作用

通过原生质体电融合得到经EGFP标记的外源细菌(蒽高效降解菌An和表面活性剂产生菌P)与黄麻根际优势菌融合的2株融合子Tu-An与融合子Tu-P,然后将两种融合子以及出发菌株分别定殖到播种了黄麻(Corchoruscapsulari)的蒽污染土壤中,对不同污染物浓度下的细菌定殖、植物生长及蒽降解做了初步研究.研究表明,在相同的初始接种量下,融合子的定殖数量明显高于出发菌株;在两种融合子共存的条件下,定殖数量也略高于单一融合子的定殖数量.在接种外源菌的土壤中,植物获得了更好的生长条件,得以良好生长;而没有投加降解菌的组别中,黄麻的生长明显受到了较严重的抑制.投加外源降解菌可以促进生物降解,达到生物强化的目的.实验研究说明,把外源降解菌投加到污染土壤中进行生物强化修复是可行的.图3表2参20     

土壤中总石油烃污染（TPH）的微生物降解与修复研究进展

微生物降解和修复是处理土壤中总石油烃(TPH)污染最简单、有效的方法之一.论文阐述了土壤TPH污染的产生、危害以及物理、化学、生物等修复方法的各自特点,其中重点介绍了微生物修复方法,论述了土壤中TPH在微生物表面的吸附、转运,在微生物体内的降解以及相关降解酶及基因;详细介绍了电子受体、温度、pH、营养元素等外界因素对微生物修复TPH污染的影响,在此基础上对土壤TPH污染的微生物修复现状和发展趋势进行了讨论.     

甲磺隆污染土壤的生物修复

在室内条件下,研究高效降解菌MD对甲磺隆污染环境的修复作用.结果表明,在土壤中,甲磺隆的降解顺序是:加菌鲜土>加菌灭菌土>鲜土>灭菌土,在添加MD时,1.0mg*l-1甲磺隆的降解速率明显高于10.0mg*l-1;在加菌土壤中,甲磺隆的降解遵循一级动力学方程;在土壤培养实验中,用菌处理10d的培养土壤中的生长量和不加药对照基本无差别.     

植物-微生物修复石油烃污染土壤与根际微生态环境变化

石油烃作为一类持久性难降解有机污染物对土壤环境质量产生严重的危害。以天津大港油田原油污染土壤中筛选出的耐低温高效石油烃降解菌为靶细胞,以小麦、紫花苜蓿作为供试植物,利用盆栽试验,对植物-外源菌协同修复体系中的脱氢酶活性和土壤微生物多样性进行研究,分析其变化及其与石油烃降解率的关系。结果表明植物-微生物协同修复对石油烃具有较好的降解能力,其中小麦-固定化外源菌组具有最高的降解率,石油烃含量从最初的30 600 mg獉kg-1下降为24 300 mg獉kg-1,降解率为20.6%,并且其试验后期石油烃的降解率最大,远远高于其他时期,表现出良好的修复潜力。外源菌投加的初始阶段会迅速提高脱氢酶活性,然而这种影响随着降解时间延长而逐渐减弱。初期脱氢酶活性与总石油烃的降解存在较好的相关性,脱氢酶活性可以在一定程度上表征土壤石油烃的降解情况。微生物多样性与总石油烃降解也存在一定的相关性。     

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     

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.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

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.     

Cost‐effective conservation of an endangered frog under uncertainty

How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.     

Parasitic wasps orient to green leaf volatiles

Summary Undamaged plants emit low levels of green leaf volatiles (GLVs), while caterpillar-damaged and artificially damaged plants emit relatively higher levels of certain GLVs. Female braconid parasitoids,Microplitis croceipes, oriented to both damaged plants and to individual GLVs in no-choice tests in a wind tunnel, but seldom oriented to undamaged plants. Female ichneumonid parasitoids,Netelia heroica, also oriented to individual GLVs in a wind tunnel. Males of both wasp species failed to orient to the GLVs. These data show that leaf-feeding caterpillars can cause the release of GLVs, and that parasitic wasps can respond to these odors by flying upwind (chemoanemotactic response), which brings the wasps to their caterpillar hosts. This supports the hypothesis that plants communicate with members of the third trophic level,i.e., plants under herbivore attack emit chemical signals that guide natural enemies of herbivores to sites of plant damage. In this interaction, the GLVs serve as tritrophic plant-to-parasitoid synomones. That parasitoids from two different wasp families oriented to GLVs suggests that the response may be widespread among the Hymenoptera.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture     

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.