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1.
利用乌鲁木齐2014年3月1日至2015年2月28日PM2.5、PM10、SO2、CO、NO2、O3浓度的日平均数据,结合相应气象要素资料,分析了大气污染物浓度的逐日变化、季节变化特征.建立了基于气体污染物的PM2.5浓度预测模型,探讨了污染物浓度与气象要素的相关性.结果表明:(1)整个1年期间PM2.5、PM10、SO2、NO2、O3年平均浓度分别为67.9、159.3、24.9、56.1、31.5μg·m-3,CO为1.4 mg·m-3.(2)各污染物浓度频率分布不一.期间SO2的污染并未超标,NO2超标率为15.3%,说明"煤改气"能源结构的调整对SO2浓度的降低起到了积极作用,但是由于机动车保有量的增加,使得机动车排放的NO2浓度超过了燃煤.(3)PM2.5与PM10、SO2、CO、NO2、O3具有很强的相关性,尤其与SO2、CO、NO2更为明显,说明机动车尾气和化石燃料的燃烧是乌鲁木齐市PM2.5的重要来源,此外,建立了基于气体污染物的PM2.5浓度预测模型为:CPM2.5=0.21376CPM10+0.42422CSO2+41.66384CCO-0.24325CNO2+0.12466CO3-24.15316.(4)PM2.5、SO2和CO均与气温和水汽压存在较大的负线性相关关系,与O3呈显著的正相关关系.相对湿度与O3浓度的相关性最高为-0.62,与CO有一定的正相关关系,与其他污染物的相关性不大.风速对大气污染的影响较小.日照时数对污染物也有一定影响.  相似文献   

2.
广州市区大气污染特征与影响因子分析   总被引:9,自引:0,他引:9  
以2000—2004年广州市国控测点的空气环境质量自动监测结果为基础数据,以我国《大气环境质量标准》的日平均质量浓度二级标准为依据计算广州市2000—2004年的各大气污染物的指数及污染负荷率,阐明广州市区主要大气污染物SO2、NO2、PM10、CO的地域分布特征、季节变化特征、年际变化特征以及由于大气中的酸性物质而形成的酸雨的变化特征并提出研究对策。结果表明:各污染物质量浓度存在明显的季节变化规律,除SO2春夏秋季污染最严重,其余几项污染程度由高到低的顺序均为冬季,春季,秋季,夏季。近5年来空气中的一氧化碳呈显著下降趋势,但二氧化硫、二氧化氮和可吸入颗粒物则呈显著上升趋势,综合污染指数也呈明显上升趋势;酸雨频率呈不显著上升且夏秋季污染大于春冬两季。广州市大气污染分布规律与风向频率以北和东北偏北方向较大,东和东南方向次之的分布基本一致。  相似文献   

3.
为研究春运期间北京市PM2.5和气态污染物的污染特征,根据35个空气监测子站周边环境类型的不同将北京市划分为城区、郊区、对照区和交通密集区.结合春运期间的人为活动,比较分析各类污染物在各区域的日均浓度变化特征;将PM2.5日均浓度与SO2、NO2、CO、O3日均浓度及北京市的日均温度、相对湿度、风级进行相关性分析.结果显示,春运期间北京市PM2.5污染最严重,超过《环境空气质量标准》二级标准的天数占45%;PM2.5日均浓度变化趋势与春运客流量变化具有较好的一致性;各区域PM2.5、SO2、NO2和CO的日均浓度均符合交通密集区城区郊区对照区的分布,而O3的情况为对照区郊区城区交通密集区;各区域PM2.5浓度分别与该区域SO2、NO2、CO浓度呈正相关,与O3浓度呈负相关;各区域PM2.5浓度与温度未见相关性,与相对湿度呈正相关,与风级呈负相关.本文的研究结果表明,交通运输、烟花燃放和气象因子对春运期间PM2.5的污染特征影响较大.  相似文献   

4.
以往对PM2.5的研究多集中在气象因子或单一空气污染物对PM2.5质量浓度变化的影响,未考虑多种空气污染物对PM2.5质量浓度的协同作用。通过哈尔滨市环保局发布的2014年1月份(共31 d)市区内主要空气污染物SO2、NO2、PM10、CO、O3、PM2.5的质量浓度数据,运用相关性分析、PLS1和通径分析方法,研究哈尔滨市区内主要空气污染物对PM2.5质量浓度变化的直接影响、通过其他空气污染物的间接影响及污染物之间的协同作用。结果表明,SO2、NO2、PM10、CO与PM2.5质量浓度显著性相关,O3与PM2.5质量浓度相关性不显著,SO2、NO2、PM10、CO之间存在严重的复相关性。依据相关性分析结果,建立了SO2、NO2、PM10、CO对PM2.5质量浓度的PSL1模型,模型的拟合优度r2为0.852,模型拟合良好。对所建立的模型进行通径分析,结果显示,SO2、NO2、PM10、CO对PM2.5质量浓度变化的直接作用分别为0.005、-0.142、-0.140、1.191,CO对PM2.5质量浓度变化的直接影响作用最大。SO2、NO2、PM10通过CO对PM2.5质量浓度变化的间接作用分别为0.706、1.011、1.118均大于它们对PM2.5质量浓度变化的直接作用。SO2、NO2、PM10、CO对PM2.5质量浓度变化的总决定系数为85.9%。CO是主要空气污染物中影响PM2.5质量浓度变化的主要因素,降低冬季煤炭供暖期CO的排放量,有利于提高空气环境质量,降低对人体的健康危害。  相似文献   

5.
郑煜  邓兰 《生态环境》2014,(12):1953-1957
以往对PM2.5的研究多集中在气象因子或单一空气污染物对PM2.5质量浓度变化的影响,未考虑多种空气污染物对PM2.5质量浓度的协同作用。通过哈尔滨市环保局发布的2014年1月份(共31 d)市区内主要空气污染物SO2、NO2、PM10、CO、O3、PM2.5的质量浓度数据,运用相关性分析、PLS1和通径分析方法,研究哈尔滨市区内主要空气污染物对PM2.5质量浓度变化的直接影响、通过其他空气污染物的间接影响及污染物之间的协同作用。结果表明,SO2、NO2、PM10、CO 与 PM2.5质量浓度显著性相关,O3与 PM2.5质量浓度相关性不显著,SO2、NO2、PM10、CO 之间存在严重的复相关性。依据相关性分析结果,建立了SO2、NO2、PM10、CO对PM2.5质量浓度的PSL1模型,模型的拟合优度r2为0.852,模型拟合良好。对所建立的模型进行通径分析,结果显示,SO2、NO2、PM10、CO对PM2.5质量浓度变化的直接作用分别为0.005、-0.142、-0.140、1.191,CO对PM2.5质量浓度变化的直接影响作用最大。SO2、NO2、PM10通过CO对PM2.5质量浓度变化的间接作用分别为0.706、1.011、1.118均大于它们对PM2.5质量浓度变化的直接作用。SO2、NO2、PM10、CO对PM2.5质量浓度变化的总决定系数为85.9%。CO是主要空气污染物中影响PM2.5质量浓度变化的主要因素,降低冬季煤炭供暖期CO的排放量,有利于提高空气环境质量,降低对人体的健康危害。  相似文献   

6.
稳定气象条件对天津市环境空气质量的影响   总被引:2,自引:0,他引:2  
环境空气中污染物浓度不仅与污染源的排放有关,更与气象条件的变化密不可分。在不利气象条件下,空气中污染物浓度可能在极短时间内就出现峰值,造成城市空气质量迅速恶化。通过对天津市2005年11月上旬连续出现的空气污染实证,分析了主要气象因子(温度、相对湿度、能见度)与空气污染物(PM10、SO2、NO2)之间的关系,探讨了稳定天气条件对空气环境质量的影响。  相似文献   

7.
利用嘉兴2012年10月—2013年9月污染气体和PM2.5的连续观测资料,结合HYSPLIT_4轨迹模式计算得到的观测期间嘉兴不同季节的主导气团,分析了嘉兴市大气污染物的变化特征及不同季节下不同气团类型对该地污染物的影响.结果表明,嘉兴市CO、SO2、NO2和PM2.5日变化为双峰型分布,峰值位于07∶00—09∶00和16∶00—18∶00;O3呈单峰分布,峰值位于14∶00,这与人为活动和大气边界层变化密切相关.大气污染物具有显著的季节变化特征,SO2、CO和PM2.5冬季高(43.5,950.3,79.8μg·m-3),夏季低(21.5、522.4、38.0μg·m-3);NO2在春季最高(49.9μg·m-3),夏季最低(30.4μg·m-3);O3夏季最高(88.9μg·m-3),冬季最低(17.2μg·m-3).影响嘉兴的主导气团的来源和路径存在显著季节变化,不同气团对大气污染物的分布影响较大,局地气团下SO2的浓度显著降低;大陆气团下污染物浓度普遍偏高,SO2、CO、NO2和PM2.5分别是海洋性气团的1.6—3.0、1.5—1.6、1.6—2.0和1.5—2.3倍;海洋性气团下污染物浓度普遍较低;混合性气团对应的污染物水平介于海洋性气团和大陆气团之间.  相似文献   

8.
天津夏季地面O3浓度变化规律与影响因素   总被引:2,自引:1,他引:1  
臭氧是城市污染大气中的首要光化学污染物,其变化规律与前体物(NO、NO2和CO)和气象因素关系密切.利用2008年夏季天津城区地面大气O3、相关前体物和气象因素等观测数据,研究了O3浓度水平和时间变化规律,重点分析了7月3日-8月5日O3与NO、NO2和CO等前体物及气象因素(气温、相对湿度和风速)的相关性.结果表明,天津城区夏季O3存在一定的污染,超标时段多发生在13:00-19:00,这一时段对应高温、低湿、大风的天气条件;NO、NO2和CO作为O3的前体物,昼间其浓度与O3浓度呈线性负相关,夜间相互作用较为复杂,相关性显著降低;气象因素对O3浓度影响明显,高温、低湿利于光化学反应的进行,O3浓度与风速呈正相关表明可能有外来源的存在.  相似文献   

9.
利用2016—2020年上海市PM_(10)、PM_(2.5)、SO_2、NO_2、O_3的质量浓度和温度、相对湿度、平均风速、水平能见度气象条件,分析了上海市PM_(10)、PM_(2.5)、SO_2、NO_2、O_3污染物的时间变化趋势。同时,利用多元线性回归模型及BP神经网络建立污染物与气象因素之间的相关关系,对其质量浓度进行预测,分析对比不同模型的预测结果。研究表明:2016—2020年上海市大气污染物质量浓度随时间变化整体呈现下降趋势;污染物质量浓度季节性差异显著,PM_(2.5)及PM_(10)质量浓度呈现"冬高夏低",而O_3质量浓度呈现"冬低夏高";可吸入颗粒物质量浓度(PM_(2.5)、PM_(10))与SO_2、NO_2质量浓度,O_3质量浓度与NO_2的质量浓度之间存在显著相关性;多元线性回归分析表明相对湿度、平均风速及水平能见度3个气象因素对上海市PM_(2.5)、PM_(10)质量浓度产生显著影响;温度、相对湿度、平均风速及水平能见度4个气象因素对上海市O_3质量浓度产生显著影响;多元线性回归分析表明上海市PM_(10)质量浓度与温度之间显著性水平为0.303,意味着温度对上海市大气PM_(10)质量浓度并没有产生显著影响;PM_(10)质量浓度随相对湿度的增加、平均气压及水平能见度的增大而减小;O_3质量浓度则与温度和平均风速呈正相关,与相对湿度和水平能见度呈负相关。相比多元线性回归,BP神经网络在预测上海市气象污染物质量浓度表现出强大的泛化能力,PM_(2.5)、PM_(10)、NO_2与O_3的真实值与预测值相关系数(r~2)分别为98.6%,97.4%,97.6%和98.3%。  相似文献   

10.
利用山东省济南、青岛2001—2010年以及其他7个重点城市2005—2010年逐日空气污染指数(API)和同期的常规气象资料,运用统计方法,分析了各市空气质量年、季变化特征,并利用SPSS软件进一步分析探讨了API指数与风速、气温、降水、湿度、日照时数等气象因子的相关关系。结果表明:济南由于受能源结构、地形、气象条件等因素的影响,API指数累年平均值最大达到91.2,沿海城市空气质量明显好于内陆城市,日照 API 指数最小仅为56.5;从年际变化来看,济南由于加强对空气污染的治理,空气质量明显改善,API指数呈逐年下降趋势,其他城市有不同程度的增加或减小。空气质量具有明显的季节变化,各城市均是夏季空气质量最好,优良率天数频率最多,冬季最差,济南冬季发生轻微污染以上天数的频率最大占39.8%;各城市均以 PM10为首要污染物出现的频率为最多,出现以 NO2、SO2为首要污染物频率最多的城市分别是枣庄、潍坊,出现空气质量为优频率最多的城市是日照;各城市4季 API 指数与同期常规气象要素密切相关,4季API指数与降水均呈负相关,除济南春季外,与风速基本呈负相关,春、夏、秋3个季节API指数与相对湿度基本均成负相关,冬季API指数与日照时数成负相关、与气温、相对湿度成正相关。  相似文献   

11.
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  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
Effects of Coffee Management on Deforestation Rates and Forest Integrity   总被引:1,自引:0,他引:1  
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  相似文献   

16.
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.  相似文献   

17.
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  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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