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1.
Surrogate species approaches, including flagship, focal, keystone, indicator, and umbrella, are considered an effective means of conservation planning. For conservation biologists to apply surrogates with confidence, they must have some idea of the effectiveness of surrogates for the circumstances in which they will be applied. We reviewed tests of the effectiveness of surrogate species planning to see if research supports the development of generalized rules for (1) determining when and where surrogate species are an effective conservation tool and (2) how surrogate species should be selected such that the resulting conservation plan will effectively protect biodiversity or achieve other conservation goals. The context and methods of published studies were so diverse that we could not draw general conclusions about the spatial or temporal scales, or ecosystems or taxonomic groups for which surrogate species approaches will succeed. The science of surrogate species can progress by (1) establishing methods to compare diverse measures of effectiveness; (2) taking advantage of data-rich regions to examine the potential effectiveness of surrogate approaches; (3) incorporating spatial scale as an explanatory variable; (4) evaluating surrogate species approaches at broader temporal scales; (5) seeking patterns that will lead to hypothesis driven research; and (6) monitoring surrogate species and their target species.  相似文献   

2.
评世界保护联盟新的物种受威胁分类系统草案   总被引:2,自引:0,他引:2  
为了进一步了解物种受威胁的情况和发展,以加强物种保护工作,世界保护联盟制定了一个新的物种受威胁分类系统草案,把物种受威胁的程度分为9个级别,即绝灭种、野生状态下的绝灭种、极危种、濒危种、渐危种、敏感种、安全的/危险性小的种、不充分了解的种和未估价的种。本文对这个分类系统草案作了简略的评介。  相似文献   

3.
CITES(濒危野生动植物国际贸易公约)是一个通过控制贸易的方法来维护物种生存及其持续利用的国际法规,其附录中所列的物种是重点管理的对象,主要根据现有的Berne标准来确定。但是,长期的实践证明,它已不能满足实际的需要。1992年6月CITES常务委员会要求世界保护联盟协助制定一个简明、实用、科学和客观的新标准,本文对此作一简介和讨论。  相似文献   

4.
Florida has one of the two worst non-indigenous invasive species problems in the United States, and all such species are considered by statute to be a potential ecological problem. Unfortunately, little information is available about most of Florida's invasive species. Here, we provide information on range expansion of a population of one of the lesser-known species. The Palm Beach County, Florida, population of the northern curly-tailed lizard, Leiocephalus carinatus armouri, was examined for north–south expansion of its previously documented range. Observations were conducted as contiguous expansion outward from the previously known range. We found a substantial contiguous range expansion by a minimum of 46.3 km to the south and 34.1 km to the north. This species appears to be closely associated with coastal habitat degradation in the form of human infrastructure, especially ageing pavement, sea walls, buildings, and bridge bases.  相似文献   

5.
《遗传学报》2021,48(10):867-871
Although many species have gone extinct, their genetic components might exist in extant species because of ancient hybridization. Via advances in genome sequencing and development of modern population genetics, one can find the legacy of unknown or extinct species in the context of available genomes from extant species. Such discovery can be used as a strategy to search for hidden species or fossils in conservation biology and archeology, gain novel insight into complex evolutionary history, and provide the new sources of genetic variation for breeding and trait improvement in agriculture.  相似文献   

6.
北京市建成区绿地植物物种来源分析   总被引:1,自引:0,他引:1  
为探讨北京市建成区绿地植物的物种构成、外来植物组成及其在不同功能区的分布,采用机械布点和随机抽样法对北京市建成区绿地植物资源进行系统调查。结果表明:(1)北京市建成区绿地植物外来引进种173种,外来归化入侵种20余种:(2)外来引进种以国内引进为主,境外起源物种中美洲和欧亚区系植物占绝对优势:(3)外来种丰度按大小排列为:大型公园〉高等院校〉居住区绿地〉街头绿地/街心花园〉附属绿地〉街道绿地〉片林绿地,而各绿地类型的入侵种数量没有显著差异。  相似文献   

7.
In Australia's arid and semi‐arid zone, most aquatic habitats are nonpermanent. Although approximately 70% of its land surface belongs to these zones, very little is known of the iconic ‘large branchiopods’ that inhabit these important and widespread habitats. In the present study, we investigated 737 Australian specimens of the spinicaudatan taxa Caenestheria and Caenestheriella with a combination of one mitochondrial (cytochrome oxidase subunit I; COI) and three nuclear (elongation factor 1α, internal transcribed spacer 2, and 28S) markers to assess the diversity of species, their phylogenetic relationships, and phylogeographical history. The initial species delimitation was based on COI employing a combination of phylogenetic analyses and two automated approaches to species delimitation (general mixed Yule coalescent model and Automated Barcode Gap Discovery). The outcome was tested by the nuclear markers and considered under differing species concepts. The number of delineated species ranged from 14–27, in no case being in full agreement with any of the two automated approaches. The lower numbers resulted if inferred reproductive isolation, as required for the biological or Hennigian species concept, was employed. Although nuclear markers did not indicate ongoing reproduction, the lack of sympatric co‐occurrences inhibited inferences of definitive reproductive isolation in several instances. If monophyly or an ‘independent evolutionary fate’ was employed, as required for the phylogenetic or evolutionary species concepts, the species' distribution was of no importance and up to 27 species could be delimitated. Because the Australian representatives of both studied genera could not be clearly separated from each other but constitute a single monophyletic clade separated from all available non‐Australian representatives of these genera, we describe a new spinicaudatan genus Ozestheria gen. nov. to accommodate these species. Populations revealed relatively small levels of genetic differentiation over large areas of central and eastern Australia. By far the most pronounced levels of genetic differentiation were observed towards the north‐eastern regions, a pattern possibly explainable by ecological conditions and the movement of nomadic water birds that disperse resting eggs. © 2015 The Linnean Society of London  相似文献   

8.
Dictyota cyanoloma has recently been described from the Mediterranean Sea and Macaronesia but doubt had arisen as to whether this species was truly native in Europe. The species is mainly found on non-natural substrata (harbour walls, marinas, boat hulls, etc.), strongly suggesting that it is an introduction. Molecular sequence information from historical herbarium samples proves the presence of D. cyanoloma in the Adriatic Sea as early as 1935. Since approximately the year 2000, however, the number of records as well as the geographic range of the species has expanded significantly. The present-day distribution of D. cyanoloma occupies most of the Mediterranean Sea, Macaronesia, NW Africa and southern Portugal, but recent records from Galicia and SW England (Falmouth, Cornwall) indicate that the species is rapidly expanding northward. Collections from Australia demonstrated that the species is also present from Perth in Western Australia, over much of the southern Australian coastline up to Minnie Water in New South Wales. Phylogenetic analyses resolve D. cyanoloma in a sister clade to a previously unreported Australian Dictyota species. Analysis of genetic diversity of the mitochondrial markers (nad6–nad11 and atp9–orf11) reveals that even though Australian populations contain a much higher haplotype richness, European populations are also fairly diverse. Furthermore, only two out of 25 haplotypes are shared between both regions. These somewhat counterintuitive results could be indicative of a more complicated introduction history.  相似文献   

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11.
The subterranean genus Niphargus is one of the most species‐rich genera among freshwater amphipods in the world, distributed in the Western Palearctic. Thus far, taxonomic and phylogenetic research has focused mainly on the European half of the genus range. In this study, 25 populations of Niphargus from Iran, Lebanon and the Crimean Peninsula were investigated. Bayesian inference based on 28S, H3 and COI gene sequences suggests that populations from the area belong to four different clades. Three species from Crimea and one species from Iran are nested at basal nodes, indicating their rather ancient origin. The rest of the species are younger and belong to two separate clades. One Crimean species is a sister‐species to east Romanian species. The second clade includes one species from Lebanon and all but one population from Iran. The origin of this clade corresponds to marine transgression between the Black Sea and Mediterranean approximately 12 Mya. This clade was further investigated taxonomically. Revision of qualitative morphological traits and unilocus species delimitation methods using COI suggest that this clade comprises 12–16 species, of which only three have been described so far. Multilocus coalescence delimitation methods (using fragments of COI, 28S, H3 and ITS) strongly supported 11 of these species. The remaining populations comprise at least two species complexes that require further and more detailed taxonomic research. © 2015 The Linnean Society of London  相似文献   

12.
With many species predicted to respond to a changing climate by shifting their distribution to climatically suitable areas, the effectiveness of static protected areas (PAs) is in question. The Madagascan PA network area has quadrupled over the past 15 years, and, although conservation planning techniques were employed to prioritise suitable areas for protection during this process, climate change impacts were not considered. We make use of species distribution models for 750 Madagascan vertebrate species to assess the potential impacts of climate change on (1) species richness across Madagascar, (2) species gain, loss and turnover in Madagascar's PAs and (3) PA network representativeness. Results indicate that Madagascar is predicted to experience substantial shifts in species richness, with most PAs predicted to experience high rates of species turnover. Provided there are no barriers to species movements, the representativeness of the current PA network will remain high for the species that are predicted to survive changes in climate by 2070, suggesting that little benefit will be gained from establishing new PAs. However, this rests on the assumption of mobility through areas currently characterised by fragmentation and anthropogenic activity, something that will require considerable expansion in conservation efforts in order to achieve.  相似文献   

13.
关于物种濒危等级标准之探讨--对IUCN物种濒危等级的思考   总被引:10,自引:3,他引:7  
为了保存地球上的生物多样性,我们需要根据物种的种群数量与分布、种群数量波动与分布区下降速率来评定濒危物种的濒危等级,并针对物种的濒危等级提出具体的保护措施。1994年11月,IUCN第40次理事会会议正式通过了经过修订的Mace-Lande物种濒危等级标准作为IUCN物种濒危等级标准。IUCN濒危物种红色名录虽然不是国际法和国家法律,但是对于政府间组织、非政府组织的保护决策以及各国的自然法律法规的制定有着深远的影响,在保护生物学理论研究中也发挥了一定作用。我们在研究制定中国水生野生生物濒危等级标准时发现,如果直接应用IUCN物种濒危等级标准评定水生野生生物濒危等级将存在一些问题。如:(1)如何区别对待那些本来就数量稀少、分布区狭窄的物种和那些由于人类活动而导致其种群数量与生境面积急剧下降的物种?(2)不同的动物类群能否应用同一濒危标准尺度?(3)如何区别对待物种边缘分布区和核心分布区的种群数量与密度的差异?(4)如何处理种群的局部灭绝、局部濒危?(5)一些濒危物种在野生环境中濒危,但是这些物种可以人工繁殖,如何处理可以人工繁殖的濒危物种?(6)如果没有种群与栖息地的精确历史资料和统计数据,怎样应用物种的濒危标准评估其濒危等级?在实践中,我们针对这些问题提出了解决方案。考虑与国际流行的IUCN物种濒危等级标准接轨,我们提出来一个由“无危”、“值得关注”、“受胁”、“濒危”和“灭绝”等5个级构成的濒危等级系统,其中“值得关注”、“受胁”、“濒危”又分为“一般”与“高度”两个亚等级。我们提出应区分“生态濒危物种”、“进化濒危物种”;对于不同生物类群,应区分物种的生活史对策,制定不同生活史物种的濒危标准。对于r-对策物种,引入“经济灭绝”这一等级,将这一等级对应于“受胁”等级,以解决缺少物种数量的统计数据和历史数据这一难题;区别对待特有物种,将其濒危等级提升一等;引进集合种群(metapopulation)概念,将集合种群的局域种群(local population)作为“个体”对待。  相似文献   

14.
指示种、伞护种和旗舰种等的运用常常可以作为解决保护生物学问题的捷径。指示种被用来评价环境中人为干扰因素的程度,监测其他物种的种群动态,或用于确定生物多样性较高的区域;伞护种则常用来确定需保护生境的类型和面积;而旗舰种被用于引起公众对保护行为的关注。本文试图对上述术语和概念在使用上加以明确区分,并对其应用提出一些指导性原则。认为针对上述不同类型的代理种,使用的目的和选择的标准应有所不同,彼此不能混淆使用。  相似文献   

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Abstract The early life history stages of anurans in the Family Bufonidae often possess chemicals that are noxious or toxic to predators. Predators with no evolutionary history of exposure to bufomds may be particularly susceptible to these toxins. We conducted a series of laboratory experiments to investigate the toxic effects of eggs, hatchlings and tadpoles of the introduced toad, Bufo marinus (Linnaeus), on native Australian aquatic predators. There was considerable interspecific and intraspecific variation in these effects. Bufo marinus were highly toxic to some predator species, but were readily consumed by other species without apparent ill effect. Interspecific variation in toxic effects was not related to predator feeding mode or the number of B. marinus ingested by predators, and there was no clear pattern of distribution of vulnerability among species within higher taxa. Intraspecific variation in responses to toxins may result from individual variation in the resistance of predators to B. marinus toxins, or from individual variation in toxicity among B. marinus. Some native species adversely affected by B. marinus appeared unable to detect and avoid B. marinus toxins. This may result from a general inability to assess the toxicity of food items or from a lack of evolutionary exposure to B. marinus toxins.  相似文献   

17.
Abstract. I examined a data set of 77 protected areas in the USA (including national and state parks) to determine which of the following variables most strongly influence alien plant species richness: park area, climate (temperature and precipitation), native species richness, visitation rate, local human population size, total road length, park shape and duration of European settlement. Many of these predictor variables are intercorrelated, so I used multiple regression to help separate their effects. In support of previous studies, native species richness was the best single predictor of alien species richness, probably because it was a good estimator of both park area and habitat diversity available for establishment of alien species. Other significant predictors of alien species richness were years of occupation of the area by European settlers and the human population size of adjacent counties. Climate, visitation rate, road length and park shape did not influence alien species richness. The proportion of alien species (alien richness/native richness) is inversely related to park area, in agreement with a previous study. By identifying which variables are most important in determining alien species richness, such findings suggest ways to reduce alien species establishment.  相似文献   

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19.
Tropical forests are suffering from increasing intensities and frequency of disturbances. As a result, non-native species accidentally introduced or intentionally planted for farming, plantations, and ornamental purposes may spread and potentially invade undisturbed native forest. It is not known if these introduced species will become invasive, as a result of recurrent natural disturbances such as hurricanes. Using data from three censuses (spanning 15 years) of a 16-ha subtropical wet forest plot, we investigated the impact of two hurricanes on populations of plant species that were planted in farms and plantations that were then abandoned and from the natural spread of species introduced into Puerto Rico in the past. The populations of four species (Citrus paradis, Mangifera indica, Musa sp., and Simarouba glauca) changed little over time. Six species (Artocarpus altilis, Calophyllum calaba, Genipa americana, Hibiscus pernambucensis, Syzygium jambos, and Swietenia macrophylla) declined between the first two censuses after Hurricane Hugo, then increased again in Census 3 after Hurricane Georges. Spathodea campanulata gradually increased from census to census, while Coffea arabica declined. These introduced species represent only a small part of the forest basal area and few show signs of increasing over time. The number of stems per plant, new recruits, and the growth rates of these introduced species were within the ranges of those for native plant species. The mortality rates over both census intervals were significantly lower for introduced species (<5% year−1) than for native ones (15% year−1). Many new recruits established after Hurricane Hugo (prior to this study) had opened the forest canopy and these high mortality rates reflect their death as the canopy recovered. Only Swietenia macrophylla and Syzygium jambos showed an increase in stem numbers in the closed canopy area of forest that had suffered limited human disturbance in the past. A future increase in frequency of disturbance may enable greater stem numbers of introduced species to establish, while lower-mortality rates compared to native species, may allow them to persist during inter-hurricane intervals. An increase in the population of introduced species, especially for those that grow into large trees, may have an impact on this tropical forest in the future.  相似文献   

20.
Abbot P 《Molecular ecology》2011,20(22):4587-4589
Nearly 25 years ago, Ellstrand & Roose (1987) reviewed what was known at the time of the genetic structure of clonal plant species. What is the relationship between space and clonal fitness, they asked. What is the best way for a clone to grow within its ecological neighbourhood? The pot had been stirred 10 years previously by Janzen (1977) , who pointed out how little we know about the population biology of clonal organisms like dandelions and aphids. He wondered whether, like good curries, outward appearances masked common ingredients. Because in no small part of the advent of molecular ecology, we know more about clonal life histories today, particularly in plants ( van Dijk 2003 ; Vallejo‐Marín et al. 2010 ). Surprisingly, studies of the spatial architecture of aphid clones have been comparably rare. In this issue of Molecular Ecology, Vantaux et al. characterize the fine‐scale distribution of the black bean aphid (Aphis fabae) and in so doing, help to fill that gap. They describe a moderate degree of intermingling between aphid clones over a growing season—A. fabae clones are ‘sticky’, but only a bit. By mixing, clones directly compete with each other as well. The results of Vantaux et al. (2011) will help to integrate evolutionary patterns in aphids with the appropriate ecological scales out of which those patterns emerge.  相似文献   

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