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1.
随着转基因作物在全球范围内大规模的商业化种植,转基因作物向其野生近缘种基因漂移及其引起的环境风险成为转基因生物安全领域的新课题。野生大豆是我国最重要的生物遗传资源之一。目前,我国不但大量进口转基因大豆,而且具有自主知识产权的转基因大豆已经具备了商业化种植的技术条件,然而转基因大豆向野生大豆基因漂移及其对野生大豆物种资源的影响已成为转基因大豆在我国进行商业化种植必须解决的核心问题。从转基因大豆与野生大豆之间的基因漂移、转基因大豆与野生大豆杂交后代的适合度等方面综述了国内外在转基因大豆向野生大豆基因漂移领域的研究进展,指出了包括转基因大豆与野生大豆杂交后代适合度评价研究方面存在的问题和不足,并提出了转基因大豆向野生大豆基因漂移研究方面的未来发展趋势。  相似文献   

2.
基因污染与生态环境安全   总被引:6,自引:0,他引:6  
论述了基因污染可能对生态环境安全造成的影响。转基因作物有可能污染天然物种的基因库;有可能破坏传统农作物品种的遗传多样性,加速作物种植品种的单一化及基因资源的流失;使抗除草剂作物的基因向野生或半野生植物漂移的可能性加大,有可能创造出“超级杂草”;带有病毒型转基因作物的基因重组,有可能创造出新的植物病毒,导致新的病害;BT转基因抗虫作物分泌的毒素,在食物链中传递,很难加以控制,对非目标生物造成危害,并最终破坏自然生态系统的平衡。文章还从不同角度分析了基因污染的严重性。  相似文献   

3.
邵素琴  李建中 《环境化学》2002,21(4):415-416
随着转基因作物商品化的迅猛发展 ,转基因作物作为食品的安全性问题也愈来愈受到人们的关注 ,有关转基因食品安全性问题的报道也愈来愈多 .在其安全性问题没有达到一致认同时 ,许多国家都要求对转基因食品要加贴标签说明 .目前 ,我国在转基因作物商品化方面已处于国际领先地位 ,在我国已获准进入商品化生产的转基因农产品已有六种 ,其中包括耐贮存西红柿和抗花叶病毒的西红柿 .这些已经商品化的转基因西红柿使用的启动子、终止子及标记基因分别为 3 5S ,NOS ,ntpⅡ (覃文 ,董杰等 ,食品中转基因成分的检测 .食品科学 ,2 0 0 1 ,2 2 (…  相似文献   

4.
转基因作物对鱼类的生态毒理效应研究综述   总被引:1,自引:0,他引:1  
转基因作物潜在的健康和环境风险一直以来颇受争议,转基因作物加工成动物饲料后可能会诱导动物产生免疫应激反应,影响动物的生长发育、繁殖等。鱼类是水生脊椎动物的代表,已广泛应用于水环境的监测,但目前转基因作物对鱼类的饲用安全性研究还相对较少。文章基于转基因作物作为鱼饲料原料对鱼类生态毒理学效应的研究现状,综述了转基因作物对鱼的生长表现、生理生化、脏器功能及发育、组织病理以及行为活动等方面的生态毒理学效应,分析了当前研究中存在的问题,并对今后的研究趋势进行了探讨。  相似文献   

5.
院士讲座     
中国工程院院士、原湖南农业大学校长、博士生导师官春云教授应邀于 2 0 0 4年 4月 5日来我院讲学 ,报告题目为《转基因作物与转基因油菜》 ,我院园林专业、园艺专业学生及教师 40 0余人与会听取了报告 ,会后师生与官院士进行了热情的交流。院士讲座$湖南环境生物职业技术学院科研处  相似文献   

6.
转基因作物潜在的健康和环境风险一直以来颇受争议,转基因作物加工成动物饲料后可能会诱导动物产生免疫应激反应,影响动物的生长发育、繁殖等。鱼类是水生脊椎动物的代表,已广泛应用于水环境的监测,但目前转基因作物对鱼类的饲用安全性研究还相对较少。文章基于转基因作物作为鱼饲料原料对鱼类生态毒理学效应的研究现状,综述了转基因作物对鱼的生长表现、生理生化、脏器功能及发育、组织病理以及行为活动等方面的生态毒理学效应,分析了当前研究中存在的问题,并对今后的研究趋势进行了探讨。  相似文献   

7.
随着转基因作物的大规模商业化种植,转基因作物的花粉漂移所引起的生物安全问题倍受关注.以抗小麦黄花叶病毒(WYMV)转基因冬小麦品种N12-1为花粉供体材料,连续2 a在江苏省徐州市转基因作物环境安全实验基地进行可控的农田试验.为了研究风向对转基因小麦花粉漂移的影响,采用同心圆设计,在花粉供体周围8个方向不同距离处检测小麦花粉密度,结果显示8个方向上转基因小麦花粉密度均随与花粉源距离的增加而显著下降,但不同方向小麦花粉密度的衰减速率有显著差异,下风向转基因小麦花粉密度的衰减速率相对较慢.同时,为了研究花粉源大小对转基因小麦花粉漂移的影响,平行设置2块不同面积(100和400 m2)的花粉源,在其下风向检测小麦花粉密度,结果显示花粉源面积增大可以在一定范围内减缓转基因小麦花粉密度的衰减速率.研究结果表明,风向、风速和距离是影响转基因小麦花粉漂移的主要因素.  相似文献   

8.
我国主要农作物转基因逃逸生态风险的初步评价   总被引:5,自引:0,他引:5  
转基因逃逸是伴随着工程作物释放的一种风险。本文首先分析了转基因逃逸的途径,并讨论了影响转基因逃逸的因素,对我国主要窕作物中逃风险进行了初步评价,一些空物中存在较大的转基因逃逸风险,最后探讨了避免和减少逃逸风险的措施。  相似文献   

9.
转基因生物环境释放风险评估的原则和一般模式   总被引:1,自引:0,他引:1  
风险评估是转基因生物环境释放依法管理的一项重要内容 ,也是生物安全研究的核心内容之一。本文在分析和比较国内外有关转基因生物风险评估方法的基础上 ,结合作者近年来对转基因生物风险评估的专题研究 ,对转基因生物环境释放风险评估的基本原则和一般模式进行了全面的描述。这种模式一般包括危险识别、风险估算和风险评价 3个连续过程 ,并可分解为 7个具体步骤  相似文献   

10.
综述了转基因作物根系分泌物和转基因作物残茬对土壤微生物和土壤动物的影响,主要表现在3方面:(1)对某些微生物和土壤动物有毒害作用;(2)为特定的微生物和土壤生物提供营养;(3)对土壤生物可能产生长期累积影响,但对此尚无定论。  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.
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.  相似文献   

14.
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.  相似文献   

15.
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   

16.
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   

17.
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.  相似文献   

18.
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   

19.
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   

20.
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   

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