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The Mediterranean Sea is subject to an ever-increasing arrival of non-indigenous marine organisms. Microcosmus squamiger is a solitary ascidian that inhabits shallow rocky littoral habitats. It probably originated in Australia and it has shown great invasive potential in other parts of the world. In the Mediterranean, M. squamiger has only been reported at a few sites in Spain and Italy. However, the closely related species Microcosmus exasperatus has been reported in several areas of the western Mediterranean. As these species can be easily confused, we re-examined most of the material from previous studies and our personal collections. In addition, sampling was done at several sites along the western Mediterranean and Atlantic coasts. The results showed that the majority of the M. exasperatus reports correspond to M. squamiger, and that M. squamiger is common on the Atlantic shores. This suggests that M. squamiger has entered the Mediterranean through the Gibraltar Strait, while the restricted distribution in the eastern Mediterranean of M. exasperatus suggests that this species is probably a Lessepsian migrant. In the Mediterranean Sea, M. squamiger has the ability to occupy extensive areas of hard substrata and to outcompete native species. Further studies are necessary to assess what impacts this invasive species have on native communities.  相似文献   

3.
Aim To evaluate the effect of mis‐specifying the correct comparison of species pools in the study of species characteristics associated with the biological introduction of exotic species. Methods We use a high quality data set on biological introductions of parrots (Aves: Psittaciformes). These data allow us to examine relationships between life history traits and probability of successful transition through an introduction stage when the species pool is both correctly and incorrectly specified. Results For the establishment of introduced parrot species, nearly half of the predictor variables showed different patterns of significance when an incorrect pool was specified. Multivariate analysis identified entirely different sets of variables as independent predictors of establishment success, depending on the species pool used. Correct pool specification identified that introduced parrot species have been more likely to establish if they have broader diets and are more sedentary. Main conclusions Conclusions from the analysis of biological introductions are likely to depend on the specification of the species pool for such analyses. In the analysis of parrot introductions, this was particularly apparent in establishment success following release. Further studies that analyse the introduction pathway need to examine the effects of pool mis‐specification so that the generality of our results can be assessed.  相似文献   

4.
《Journal of Asia》2021,24(3):688-694
Two European click beetle species, Agriotes obscurus L. (AO) and A. lineatus L. (AL) have become serious pests of agriculture in the Fraser Valley and Vancouver Island areas of British Columbia (BC), but prior to the start of this survey (2017) it was unknown if they had established elsewhere in the Province. Pitfall traps baited with sex pheromone of AO and AL were placed throughout BC in 2017–2019 and collected a total of 4,988 AO and 20,103 AL beetles in 150 trap pairs. Both species were found to be distributed throughout southern BC, including high numbers in Creston, Kelowna, Pemberton, and Salmon Arm. Traps placed in northern BC, northern Alberta, northern Idaho, or the Willamette valley in western Oregon did not collect AO or AL. Traps were also deployed for A. sputator L., a related European species that has become a serious pest of potato in eastern Canada, but this species was not collected. AO and AL traps placed in the Pemberton valley of BC also collected 474 A. ferrugineipennis (LeConte), and traps placed in the northern Okanagan valley collected 75 A. oregonensis Becker. Both are native Agriotes species not closely related to AO or AL; this is the first time A. oregonensis was collected in Canada. We discuss the potential implications of the spread of AO and AL to other agricultural areas in BC and beyond.  相似文献   

5.
In prairie ecosystems, abiotic constraints on competition can structure plant communities; however, the extent to which competition between native and exotic plant species is constrained by environmental factors is still debated. The objective of our study was to use paired field and greenhouse experiments to evaluate the competitive dynamics between two native (Danthonia californica and Deschampsia cespitosa) and two exotic (Schedonorus arundinaceus and Lolium multiflorum) grass species under varying nutrient and moisture conditions in an upland prairie in the Willamette Valley, Oregon. We hypothesized the two invasive, exotic grasses would be more competitive under high-nutrient, moderate-moisture conditions, resulting in the displacement of native grasses from these environments. In the field, the experimental reduction of competition resulted in shorter, wider plants, but only the annual grass, Lolium multiflorum, produced more aboveground biomass when competition was reduced. In the greenhouse, the two exotic grasses produced more total biomass than the two native grasses. Competitive hierarchies were influenced by nutrient and/or moisture treatments for the two exotic grasses, but not for the two native grasses. L. multiflorum dominated competitive interactions with all other grasses across treatments. In general, S. arundinaceus dominated when in competition with native grasses, and D. cespitosa produced the most biomass in monoculture or under interspecific competition with the other native grass, D. californica. D. californica, D. cespitosa, and S. arundinaceus all produced more biomass in high-moisture, high-nutrient environments, and D. cespitosa, L. multiflorum, and S. arundinaceus allocated more biomass belowground in the low nutrient treatment. Taken together, these experiments suggest the competitive superiority of the exotic grasses, especially L. multiflorum, but, contrary to our hypothesis, the native grasses were not preferentially excluded from nutrient-rich, moderately wet environments. Laurel Pfeifer-Meister and Esther M. Cole contributed equally to this work.  相似文献   

6.
Questions: Exotic plant invasion may be aided by facilitation and broad tolerance of environmental conditions, yet these processes are poorly understood in species‐rich ecosystems such as riparian zones. In the southwestern United States (US) two plant species have invaded riparian zones: tamarisk (Tamarix ramosissima, T. chinensis, and their hybrids) and Russian olive (Elaeagnus angustifolia). We addressed the following questions: (1) is Russian olive able to tolerate drier and shadier conditions than cottonwood and tamarisk? (2) Can tamarisk and cottonwood facilitate Russian olive invasion? Location: Arid riparian zones, southwestern US. Methods: We analyzed riparian tree seedling requirements in a controlled experiment, performed empirical field studies, and analyzed stable oxygen isotopes to determine the water sources used by Russian olive. Results: Russian olive survival was significantly higher in dense shade and low moisture conditions than tamarisk and cottonwood. Field observations indicated Russian olive established where flooding cannot occur, and under dense canopies of tamarisk, cottonwood, and Russian olive. Tamarisk and native riparian plant species seedlings cannot establish in these dry, shaded habitats. Russian olive can rely on upper soil water until 15 years of age, before utilizing groundwater. Conclusions: We demonstrate that even though there is little evidence of facilitation by cottonwood and tamarisk, Russian olive is able to tolerate dense shade and low moisture conditions better than tamarisk and cottonwood. There is great potential for continued spread of Russian olive throughout the southwestern US because large areas of suitable habitat exist that are not yet inhabited by this species.  相似文献   

7.
《Journal of Asia》2022,25(3):101956
The beet armyworm, Spodoptera exigua (Hübner, 1808) and the Egyptian cotton leafworm, S. littoralis (Boisduval, 1833), are amongst the most notorious agricultural pest species in Iran. Spodoptera exigua is considered a serious pest of different crops, whereas S. littoralis is known as an important pest of cotton.In this paper, the potential distribution areas of these species in Iran and the important climatic factors affecting their distribution were predicted using the MaxEnt model and the ArcGIS. The results indicate that the main environmental variables contributing to S. exigua’s distribution were precipitation of the coldest quarter (bio19), average wind speed in April (wind4), and annual precipitation (bio12). Also, minimum temperature of the coldest month (bio6), mean temperature of coldest quarter (bio11), altitude and average wind speed in May (wind5) were dominant climatic factors that affected the potential distribution of S. littoralis. These species overlapped in most parts of coastal areas in the southern and northern parts of Iran, with an average overlapping range of 33.2%. Considering their preferred host plants in Iran, it is necessary to strengthen biosurveillance programes and management of these two species in their suitable areas to prevent further invasion, which endangers agricultural security.  相似文献   

8.
Chestnut blight in south-western Germany was first reported in 1992 and is since expanding in distribution. Here we investigated the invasion history of Cryphonectria parasitica and its associated hypovirus. For this, we characterized 284 isolates collected between 1992 and 2012 for hypovirulence, vegetative compatibility (vc), mating type, and microsatellite haplotype. A total of 27 haplotypes and 15 vc types were observed, although the C. parasitica population analyzed is currently dominated to 50 % by one haplotype and to 64 % by the vc type EU-2. Structure analysis indicated two divergent genetic pools. Over 66 % of the haplotypes belonged to a pool probably originating from northern Italy. Further diversification is expected due to ongoing sexual recombination, but also to new migration and additional introductions. Cryphonectria hypovirus 1 (CHV-1) was found in four of five C. parasitica populations from Baden-Württemberg. Genetic analysis of the 35 CHV-1 isolates obtained revealed that they all belong to the German subtype, although they have clearly diverged from the first German hypovirus isolated in 1992. Our study suggests that C. parasitica has been introduced into Germany several times from two different gene pools, whereas the hypovirus most probably has a single origin.  相似文献   

9.
Non-indigenous plant species have been frequently reported as successful invaders in island environments, changing plant community composition and structure. This is the case of the sweet pittosporum (Pittosporum undulatum), native from Australia, which is one of the most successful plant invaders in the Azores archipelago. Data extracted from recent forestry inventories were used to model and map the potential distribution of P. undulatum in São Miguel, the larger island of the Azores. Current distribution of P. undulatum is related to climate, altitude and some human activity effects. Further analysis of the areas under risk of invasion showed that protected areas are under potential threat, although only a few native forest remnants seem to be threatened due to future expansion of P. undulatum, since the current distribution of these native communities has been reduced due to clearing and competition with invasive plants. We discuss the threats that any further expansion of the species will represent for low-altitude native forests, as well as the utility of species distribution models in the assessment of the areas under risk of invasion.  相似文献   

10.
Geospatial and field data were merged to characterize the invasion of an exotic macrophyte into a large (∼6192 ha), reservoir, the Chippewa Flowage, Wisconsin, USA. Multi-scale analyses provided data for quantitative models of human, abiotic and biotic influences that would explain the presence and abundance of Myriophyllum spicatum L., a widespread, aquatic species. Human and abiotic factors were analysed in a geographic information system and additional abiotic and biotic factors were sampled at 2778 sample points. Using multivariate logistic and multiple linear regressions the relationships between 29 factors and the species’ presence and abundance were quantified. M. spicatum occurred at 181 of 992 vegetated points. M. spicatum abundance was significantly influenced by two geospatial variables (wave action and water-level drawdown) and two site variables (water depth and native species presence). Separate models for shallow and deep water explained 32% and 30% of M. spicatum abundance, respectively (compared to 22.8% using all 181 points). The species’ vertical distribution (range = 0.30-4.27 m) was related to depth of winter drawdown (∼1.3 m on average) and to water depth (an indicator of decreasing light), as well as to shading by floating-leaved macrophytes. Spatial extrapolation of model predictions for M. spicatum presence indicated that a total 940 hectares are at risk for M. spicatum invasion (∼15% of the Chippewa Flowage; about 2.5 times larger than the current distribution).  相似文献   

11.
近20年外来生物入侵危害与风险评估文献计量分析   总被引:3,自引:0,他引:3  
外来生物入侵导致全球生物多样性下降,极大地威胁着生态系统健康,已造成很大的生态损失与经济损失。近年来,随着生物入侵的加剧,全球对生物入侵的研究力度不断加大。外来入侵生物的生态危害与风险评估可以为人们提供对入侵可能性和入侵方式更直接的信息,从而为管理者制定管理策略提供依据。基于最近20年间(1995—2014年)科学文献数据库Web of Science的科学引文索引数据库扩展版(SCI-E)中数据,对外来入侵生物的生态危害与风险评估方面的研究进行了文献计量分析,旨在了解当前国际研究现状,以便推动中国的生物入侵相关研究。为了全面掌握全球外来生物入侵生态危害与风险评估方面的研究,采用Bibexcel与TDA文献计量工具,对Web of Science数据库中相关文献进行了分析,去重后共获取5492篇文献。结果表明:近20年(1995—2014年)入侵生物的生态危害与风险评估方面的研究刊文量呈现前缓后剧增的趋势,2008—2014年进入了快速发展阶段,文献数量急剧增加,2014年达到最高(511篇);美国发文量远超其它国家,占据主导地位,中国刊文量排名第5。美国、澳大利亚、法国、英国、德国的研究论文影响力较大。刊文量最多的研究机构为美国农业部(USDA),中国科学院发文量排名第10位。研究学科主要为昆虫学、农艺学、植物科学、生态学,研究热点集中在生物防治、风险评估、粮食作物和经济作物的病虫害防治、杂草防控,以及生物入侵与气候变化的关系等方面。有关外来入侵生物的生态危害与风险评估的研究多集中于北美、澳大利亚和欧洲,未来要加强亚洲地区,特别是中国外来生物入侵风险评估的研究;要加强气候变化对外来生物物种特性的影响研究,更多关注入侵生物的生态控制与生态恢复方面的研究,以便更好地为今后长期有效地防控入侵生物提供理论与技术指导。  相似文献   

12.
The ecological consequences of homogenization remain relatively unexplored. One example of landscape-homogenizing is the establishment of plantations. We studied the effect of human-made forests by contrasting plant and small-mammal community composition between planted tree stands and adjacent natural habitat in two different Mediterranean habitats in Israel: (1) inland habitat where we focused on pine (Pinus halepensis) and carob (Ceratonia siliqua) stands, and (2) coastal sand dune habitat where we focused on planted acacia (Acacia saligna) stands. We first wanted to verify whether planted trees modify plant species composition, and second, if and how the small-mammal community is affected by the different habitat conditions created in plantations with different canopy cover. We were especially interested in the abundance of the commensal house mouse (Mus musculus). All tree stands underwent biotic homogenization indicated by abundance of house mice coupled with lower diversity of indigenous vegetation and small-mammal abundances and diversities. Habitat structural diversity was positively related with small-mammals diversity and was lower in artificial tree stands in both habitats. Our results suggest that using the abundance of commensal generalist species such as the house mouse relative to other more specialist small-mammals is a good approach to determine ecosystem integrity. Pre-commercial thinning treatment is a potential management tool to maintain a proportion of native tree species within the canopy of planted tree stands. However, until sufficient data is available for making generalizations, the exact level of thinning necessary to reverse the homogenization processes in man-made plantations and keeping indigenous small-mammal communities diverse and less prone to invasion must be determined empirically.  相似文献   

13.
The trade in live animals between India and Brazil dates from the late nineteenth century when European travellers traded animals of Indian origin for display in zoos. Considering the origin of coffee and sugar cane, as well as the expertise related to mineral evaluation, we need to consider that India was involved in important economic cycles of Brazil, even indirectly. This virtuous flow of trade has been maintained and intensified throughout modern history, especially after these two nations gained political independence from their colonisers, thereby becoming independent in mercantile affairs. This paper addresses the main points related to the use of animals of Indian origin in Brazil. We revisit some of the historical aspects of the process of colonisation of Brazil, as well as the importation of animals from India. The restrictions imposed on this process due to the occurrence of diseases in cattle and buffalo in India will be examined. At the end of the text, emphasis will be given to the risks of introducing exotic diseases into Brazil.  相似文献   

14.
INTRODUCTION: The need for early consideration of pediatric investigation plans (PIP) to support an indication in pediatric population has led to an increased focus on the relevance of nonclinical studies in juvenile animals (JAS). The usefulness of JAS is not yet established and a criterion for request is still a learning process. OBJECTIVE: This article compares data from JAS in all medicines approved by European centralized procedure before Pediatric Regulation (1995–2005) and data from JAS in the nonclinical information on all approved PIP (2007–2009). RESULTS: Of the 226 substances licensed by centralized procedure in 10 years, 31.9% were considered for children and 31 JAS were described in 9.7%. Since 2007, of the 205 PIP decisions, 50 PIP (24.3%) have 87 JAS planned or requested. The mean number of JAS in each medicine or PIP, increased from 1.4 to 1.7 between the two periods and the juvenile rat remained as the prevalent species. CONCLUSIONS: Results demonstrate that JAS planned/performed in EU environment has significantly increased. Birth Defects Res (Part B) 92:353–358, 2011. © 2011 Wiley‐Liss, Inc.  相似文献   

15.
Two centuries of historical, archaeological, paleontological, geological, oceanographical and biological data conclusively indicate that the periwinkle snail Littorina littorea was introduced to North America from Europe either by Norse explorers 1000 years ago or by European colonists after 1840. Available genetic data do not indicate ancient divergence of North American and European L. littorea and thus do not challenge all other evidence that it was introduced from Europe by humans.  相似文献   

16.
A Late Pleistocene spotted hyena Crocuta crocuta spelaea (Goldfuss 1823) population from the cave bear den Sloup Cave, Moravia (Czech Republic) consists of mainly adult/senior and few cub/juvenile remains and coprolites, and 139 prey bones. Hyenas used the Nicová Cave branch that is connected to the entrance area mainly as a communal den site. Prey bone damage is most visible on the imported woolly rhinoceros remains. The partly excavated prey bone accumulation consists of a single woolly mammoth Mammuthus primigenius (Blumenbach 1799) tooth (2%), mainly Coelodonta antiquitatis (Blumenbach 1807) remains (16%), 4% Bos primigenius (Bojanus 1827) and 1% each of Megaloceros giganteus (Blumenbach 1799) and Rangifer tarandus (Linnaeus 1758). The other carnivores such as Panthera leo spelaea (Goldfuss 1810), Gulo gulo (Linnaeus 1758) and Canis lupus (Linnaeus 1758) subsp. are less represented (1–3%). Wolverines might have been imported also as prey remains, whereas wolves also possibly used this cave on a short-term basis, whereas steppe lions seem to have preyed upon cave bears deeper in the cave periodically, where even skeletons of P. leo spelaea were found in the Elisabeth Cave part.  相似文献   

17.
We give a mini-review of existing European risk assessment procedures and present a newly developed and tested risk assessment tool for invasive alien species (IAS) in Germany and Austria, the “German–Austrian Black List Information System” (GABLIS). Based on the analysis of existing European national risk assessment systems, we analyse and discuss: the assessment criteria used; which impacts of IAS (biodiversity, economy) have been considered; for which taxonomic groups has the assessment been designed and tested; how many and which list categories have been used; and, the status of the assessment, i.e. legally binding or advisory. We found that the application of risk assessment systems in Europe started belatedly, however recently a considerable number of assessment systems have been developed and tested. These systems encompass a wide range of purposes and approaches, and so far, no common standard on the aspects mentioned above has been emerged.GABLIS has been developed as a trans-national and taxonomically universal risk assessment system, which takes into account solely the detrimental effects of alien species on biodiversity. We describe which kinds of impacts are considered and how the thresholds have been scaled. We present the structure of the list categories, and we discuss the necessary underlying data for assessment, the assessment criteria and their scaling, and the assessment procedure. Five basic and six complementary criteria are used to assess the alien species’ impact. GABLIS includes three main list categories (White List, Grey List, and Black List).We discuss the practicability of GABLIS by presenting the assessment results of a model taxon (fish), and by presenting the assessment protocol for a vascular plant species. We discuss the necessary data quality for assessments, and the factors which account for differences in the assessments between both countries. We also report on experiences gained in assessments (e.g., average time necessary for assessments). The lessons learnt are discussed in the national and European political context of IAS management.Finally, we explore the strengths and caveats of this approach in the context of national policy on IAS in Germany and Austria and the ongoing European political initiatives. GABLIS is intended to serve as a comprehensive, flexible, but robust risk assessment tool for Central Europe. Being a trans-national risk assessment tool, GABLIS also tests principles, which might contribute valuable insights for a future overall strategy against IAS in Europe.  相似文献   

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The seagrass Halophila stipulacea Forsskål, native to the Red Sea, is an invasive species in the Mediterranean that was recently observed offshore Grenada, in the Caribbean. Here, we document the presence of this seagrass in Dominica and St. Lucia, demonstrating it has spread across part of the eastern Caribbean. H. stipulacea in Dominica was present in seven locations along the west coast covering more than 22.9 ha of the benthos, at depths from 2 to 18 m. Populations were concentrated in or adjacent to bays frequented by recreational or commercial boats, likely vectors for the introduction. Morphological features varied from bed to bed, with depth being the predominant driving factor. H. stipulacea had a rapid mean lateral bed expansion rate of 0.5 cm d−1, with a maximum rate of >6 cm d−1. H. stipulacea patches often occurred exclusive of the otherwise dominant seagrasses of the Caribbean. The potential for the expansion of H. stipulacea, combined with its tolerance for a wide spectrum of environmental conditions, positions it as a potential threat to local and regional biodiversity.  相似文献   

20.
This study assesses crop residues in the EU from major crops using empirical models to predict crop residues from yield statistics; furthermore it analyses the inter‐annual variability of those estimates over the period 1998‐2015, identifying its main drivers across Europe. The models were constructed based on an exhaustive collection of experimental data from scientific papers for the crops: wheat, barley, rye, oats, triticale, rice, maize, sorghum, rapeseed, sunflower, soybean, potato and sugarbeet. We discuss the assumptions on the relationship between yield and the harvest index, adopted by previous studies, to interpret the experimental data, quantify the uncertainties of these models, and establish the premises to implement them at regional scale –i.e., NUTS level 3– within the EU. To cope this, we created a consolidated sub‐national statistical data along with an algorithm able to aggregate (figures are provided at country level) and disaggregate (production at 25 km grid is provided assupplementary material) estimates. The total lignocellulosic biomass production in the EU28 over the review period, according to our models, is 419 Mt, from which wheat is the major contributor (155 Mt). Our results show that maize and rapeseed are the two crops with the highest residue yield, respectively 8.9 and 8.6 t ha‐1. The spatial analysis revealed that these three crops, which, according to our results, are feedstocks highly suitable a priori for second generation biofuels in the EU and are unevenly distributed across Europe. Weather fluctuation was identified as the major driver in residue production from cereals, while, in the case of starch crops and oilseeds – which are predominant in northern Europe – corresponded to the marked production trend likely influenced by the agricultural policies and agro‐management over the review period. Our results, among others, could help to understand and quantify the ecological boundaries of the bioeconomy from agriculture.  相似文献   

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