三丁基锡和菲对鳗鲡的毒性效应（Toxic Effects of Tributyltin and Phenanthrene on Eels）

采用腹腔注射方式(每周1次,共5次)将生活于淡水或海水中的日本鳗鲡(Anguilla japonica)暴露于三丁基锡氯化物(TBTCl)和菲(Phe),以研究这两种污染物对鳗鲡的毒性效应以及该效应与鱼体所处环境盐度的关系.鳗鲡暴露于TBTCl或Phe1w后,其肝脏和脾脏的组织结构就已发生明显病变,且病变程度随着暴露时间的延长而加剧,其中海水鳗鲡比淡水鳗鲡表现更为严重;但肝体指数(HSI)和性腺组织结构均无明显变化.暴露于TBTCl4～5w后,海水鳗鲡肝脏的谷胱甘肽-S-转移酶(GST)活性比对照组显著升高,而淡水鳗鲡组无明显变化;暴露于TBTCl或Phe3w后,淡水鳗鲡的血浆皮质醇水平显著升高,但海水鳗鲡组无明显变化.TBTCl和Phe对淡水或海水鳗鲡的血浆雌二醇(E2)水平均无明显影响.以上结果表明:有机锡和菲对鳗鲡的肝脏、脾脏有毒性作用,对皮质醇分泌具有内分泌干扰作用,且该效应与暴露时间和鱼体所处环境盐度有关.     

双酚A对斑马鱼不同发育阶段的毒性及机理

对双酚A(BPA)暴露下的斑马鱼胚胎、仔鱼和成鱼三个发育阶段进行对比研究,并从代谢和DNA损伤两个角度对其致毒机理进行初步探讨.结果显示: 斑马鱼成鱼24h的LC50(8.00-10.00mg·l-1)比胚胎(16.4±0.40mg·l-1)低,表明斑马鱼成鱼更适用于急性毒性试验,而胚胎更能体现出亚急性效应和遗传效应;在5.00mg·l-1 的BPA中连续暴露48h后,胚胎和成鱼体内的BPA含量分别为373.57±39.76μg·g-1和155.78±17.97μg·g-1,即胚胎在5.00mg·l-1 BPA溶液中的蓄积能力大约是成鱼的两倍; DNA断裂检测表明BPA对斑马鱼胚胎的DNA造成了一定程度的损伤.     

全氟辛烷磺化物(PFOS)诱导斑马鱼胚胎p53基因的点突变

将斑马鱼胚胎于0μg·1-1(空白对照),5μg·l-1,16μg·l-1和50μg·l-1全氟辛烷磺化物(PFOS)溶液中暴露染毒5h,采用变性高效液相色谱方法对PCR扩增的含斑马鱼胚胎p53基因外显子7的173 bp的目标片段进行突变分析.结果显示,16μg·l-1和50μg·l-1两个处理组与对照组相比均有显著性差异,表明PFOS可以诱导斑马鱼胚胎p53基因外显子7的点突变.     

壬基酚对Americamysis bahia种群安全暴露基准浓度的确定

采用正态分布累积函数和幂函数,分别建立了壬基酚(NP)对Americamysis bahia多代种群暴露影响的浓度-种群周限增长率(λ)和浓度-种群内禀增长率(r)曲线,根据各自拟合的模型选择基准(MSC)值选择幂函数浓度-r曲线来估算种群安全暴露浓度.使用浓度-r曲线的浓度(r=0)的95%置信区间下限作为种群水平上的安全暴露基准浓度,确定了NP对Americamysis bahia种群多代安全暴露浓度(1.87μg·l-1).这个基准浓度要低于多代暴露实验所获得的NP的个体水平上的慢性繁殖毒性的安全浓度(12μg·l-1).     

低浓度五氯酚对鲫鱼血液细胞毒性的体外研究

通过细胞体外毒性试验,研究了低浓度五氯酚对鲫鱼血液淋巴细胞和红细胞的毒性影响.结果表明:在2.50—1000.00μg·l-1范围内,五氯酚对鲫鱼淋巴细胞的活性没有显著效应,但在500.00和1000.00μg·l-1(高浓度组)时,对淋巴细胞膜的完整性产生显著影响,造成乳酸脱氢酶(LDH)相对释放量增加,并随五氯酚浓度的增加和暴露时间的延长而增加.低浓度五氯酚组(5.00—1000.00μg·l-1)对红细胞溶血没有显著影响,但与二苯并[a,h]蒽联合作用产生协同效应,红细胞溶血效应明显高于两种化合物单独作用,并且随浓度的增加,血色素相对释放量显著增加.另外,鲫鱼淋巴细胞膜的完整性(LDH的释放)比淋巴细胞活性和红细胞溶血对低浓度五氯酚更敏感.     

氯化三丁基锡(TBTCl)对罗非鱼精巢细胞凋亡的影响

以雄性奥利亚罗非鱼为试验材料,分别以0、1、3、5和10μg·L-1氯化三丁基锡(TBTCl)通过接触染毒的方式,研究TBTCl对鱼类精巢细胞凋亡的影响.细胞凋亡分析结果表明,在同一染毒时间下,除染毒时间为24和48h,染毒浓度为1μg·L-1处理组与对照组之间细胞凋亡率差异不显著(P>0.05)以外,其余情况下各处理组与对照组之间差异均显著(P<0.05或P<0.01).各相邻2个浓度处理组之间,3μg·L-1处理组和5μg·L-1处理组之间细胞凋亡率差异均不显著(P>0.05),其余各组之间差异均显著(P<0.05或P<0.01).随着TBTCl浓度的升高,罗非鱼精巢细胞凋亡率逐渐升高,剂量-效应关系显著.精巢细胞Ca2+-ATP酶活性测定结果表明,在同一染毒时间下,除在染毒时间为24和96 h时,染毒浓度为1μg·L-1处理组与对照组之间差异不显著(P>0.05)以外,其余情况下各处理组与对照组之间差异均显著(P<0.05或P<0.01).在同一染毒时间下,各处理组之间,除染毒时间为24 h时,染毒浓度1μg·L-1处理组和3 μg·L-1处理组之间差异不显著(P>0.05)以外,其余情况下各处理组之间差异显著(P<0.01);随着染毒浓度的升高,Ca2+-ATP酶活性逐渐升高,并且剂量一效应关系显著(P<0.05或P<0.01).奥利亚罗非鱼精巢细胞凋亡率与精巢Ca2+-ATP酶活性间具有一定的协同关系.     

五氯酚和八氯代二苯并二嗯英复合暴露对斑马鱼胚胎发育的毒性效应

为了评价环境中五氯酚(PCP)和八氯代二苯并二嚼英(OCDD)对水环境以及鱼类的影响,以斑马鱼为模式生物,研究了PCP和OCDD对其胚胎发育的单一及复合毒性效应.结果表明,PCP单独暴露(浓度25μg·L-1～5mg·L-1)对斑马鱼胚胎发育具有较强的毒性效应,可导致胚胎孵化率显著下降,死亡率、畸形率显著上升,而OCDD单独暴露(200、500μg·L-1)对斑马鱼胚胎发育没有明显的毒性效应;OCDD与环境浓度的PCP复合暴露(OCDD PCP1:250μg·L-1 25μg·L-1;OCDD PCP2:250μg·L-1 50μg·L-1)对斑马鱼胚胎的存活与发育等没有显著影响,对斑马鱼胚胎内CYP1A基因表达以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)的酶活力也没有显著影响,在实验浓度下二者共存没有明显的复合毒性效应.     

太湖春季水体中胶体态痕量金属的含量

对太湖典型湖区水体中的胶体态痕量金属进行了定量分析. 结果表明,太湖春季水体中胶体态Cu,Zn,Pb,Fe,Mn和Cd的浓度分别为0.46-0.86μg·l-1,2.06-8.24μg·l-1,2.62-3.70μg·l-1,3.48-24.79μg·l-1,0.31-1.62μg·l-1和6.71-17.94ng·l-1,平均分别占各自总溶解态(＜1μm)的22.3%,26.3%,20.7%,58.9%,40.4%和59.2%,而胶体态Cu,Pb,Fe,Mn和Cd平均分别占各自总量的17.4%,19.1%,55.1%,1.98%和52.8%.     

林丹短期暴露对斑马鱼生长发育和繁殖的影响

以斑马鱼为受试生物,研究在低浓度(0.005、0.05、0.5峭μg·L-1)林丹暴露条件下,林丹对斑马鱼体长、体质量、肝脏指数、性腺指数、产卵量和受精率的影响.结果显示,经14 d暴露后,处理组斑马鱼体长和体质量与空白对照组或溶剂对照组之间差异不显著;与空白对照组和溶剂对照组相比,0.5μg·L-1处理组雄性和雌性斑马鱼肝脏指数均显著增加(P＜0.05),雄性斑马鱼性腺指数显著降低(P＜0.05),其他处理组无明显变化;林丹对斑马鱼产卵量和受精率表现出明显的抑制作用,与空白对照组相比,0.05和0.5μg·L-1处理组斑马鱼平均产卵量和受精率均极显著降低(P＜0.01).该研究表明林丹具有环境内分泌干扰物特性,在低浓度暴露条件下可对斑马鱼的生长发育和繁殖产生一定抑制影响.     

椒江口水体和生物体中典型有机污染物的浓度水平及来源初探

研究了椒江口海水、沉积物和生物体中苯胺、硝基苯、多氯联苯、多环芳烃的浓度水平及来源,评价了各种有机污染物在沉积物和生物体内的富集情况.结果表明,椒江口海水中苯胺、硝基苯、多氯联苯(PCBs)、多环芳烃(PAHs)的浓度范围分别为9.3-105.1μg·l-1,46.2-268.5μg·l-1,57.5-519.3ng·l-1和356.9-1021.4 ng·l-1;沉积物中苯胺、多氯联苯、多环芳烃的浓度(干重)范围分别为0.76-1.12μg·g-1,5.78-10.42 ng·g-1,77.5-165.4 ng·g-1;生物体中PCBs、PAHs的浓度(湿重)范围分别为19.51-20.62 ng·g-1,0.11-1.03 ng·g-1.生物体内PCBs的富集倍数高于PAHs,而沉积物中PAHs的富集倍数高于PCBs.海水、沉积物中的苯胺和硝基苯主要来自源于椒江口化工废水的排放,PAHs主要来源于台州火力发电厂的燃烧污染,PCBs主要来源于废旧电器拆解业污染物的排放迁移.     

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.