南四湖湿地外来入侵植物

南四湖是我国重要的淡水湖泊湿地之一。为阐明南四湖湿地外来植物的现状及入侵规律,为湿地生态系统的重建、生物多样性的保护和湿地资源开发等提供指导,通过野外调查和参考有关文献资料,对南四湖湿地外来植物进行了较为深入的研究,并与青岛、昆嵛山、滨州沿海三地作了比较。结果表明,南四湖湿地外来入侵植物有41种,隶属19科35属;以菊科和豆科为优势科;外来入侵物种中热带来源与温带来源比例相当,人为引入导致的外来入侵植物高达39%。南四湖与沿海三地相比,沿海三地外来入侵植物的种类均比南四湖湿地多,其中以经济最发达的青岛种类最多;青岛外来入侵植物中有35种在南四湖湿地未发现;南四湖湿地的特有外来入侵植物有5种,体现出湿地外来入侵植物水生特性。群落相似性分析表明,Jaccard指数和Sorenson指数呈现的规律一致,南四湖与滨州的相似性最高,其次为昆嵛山,与青岛的差异最大。通过分析南四湖湿地外来入侵植物种类和分布规律,提出了相应的防治对策。     

乐山地区外来入侵植物风险评估

[目的]全面了解乐山地区的外来入侵植物现状,为乐山地区外来入侵植物的防控提供可行性建议对策,并为防控进展研究和预警机制的建立提供参考。[方法]通过实地调查、查阅文献和标本数据库分析乐山地区外来入侵植物情况,利用层次分析法建立乐山地区外来入侵植物的评估体系,评估所有外来入侵植物的风险值,并根据等级划分标准和风险值将外来入侵植物划分为5个风险等级(I~V级)。[结果]乐山地区入侵植物种类共109种,隶属38科86属。其中菊科17属20种,为最大优势科,豆科、苋科、茄科、禾本科次之,且草本植物占优。I级风险(恶性入侵)植物有10种,II级风险(严重入侵)的有11种,III级风险(局部入侵)的有13种,IV级风险(一般入侵)的有27种,其他48种(有待观察)为V级风险。中高危害风险的外来入侵植物共34种,隶属18科32属。[结论]乐山地区外来入侵植物种类繁多且危害风险高,基于上述入侵现状和风险等级提出了防控外来植物入侵的对策。     

Impacts of Alien Invasive Species on Freshwater Fauna at Risk in Canada

Freshwater aquatic organisms in North America are disproportionately imperilled when compared to their terrestrial counterparts due to widespread habitat alteration, pollution, overexploitation and the introduction of alien species. In this review, we examine the threat factors contributing to the endangerment of freshwater fishes and molluscs in Canada and further examine the nature of alien invasive species introductions affecting aquatic species at risk. Habitat loss and degradation is the predominant threat factor for Canadian freshwater fishes and molluscs that are listed as Extinct, Extirpated, Endangered and Threatened. Alien invasive species are the second most prevalent threat for fishes, affecting 26 of 41 listed species. Alien invasive species are a threat in most parts of Canada where listed fishes are found. Most (65%) of the alien invasive species affecting listed fishes are the result of intentional introductions related to sport fishing, and the majority of these introductions are unauthorized. Fifteen fishes and two plant species are cited as alien invasive species that impact listed fishes with brown bullhead (Ameiurus nebulosus) and pumpkinseed (Lepomis gibbosus) being the most prevalent. Alien species are a threat to 6 of 11 listed mollusc species. All six species are threatened by the alien zebra mussel (Dreissena polymorpha) in the Great Lakes basin. An erratum to this article is available at .     

厦门市外来物种入侵现状及其风险评价指标体系

通过对厦门地区外来物种入侵状况的实地调查,对已有文献资料的查阅和专家咨询,整理了厦门市已入侵或值得警惕的外来植物名录。并从气候、土壤、植被生态群落结构、地貌特征、人为和自然干扰状况以及港口交通贸易等方面分析了厦门市外来生物入侵现状的原因。结合前人在外来生物入侵的风险评价方面的研究成果,针对厦门市的外来植物入侵现状,构建了适应厦门地区外来植物入侵风险评价指标体系框架,该指标体系由“移居与建群的可能性”、“危害与影响”和“预防与控制”3大部分,共计6个一级指标,17个二级指标构成。     

植物外来种的生态风险评估和管理

生物入侵是指物种借助于自身力量或外界力量 ,传入到其进化史上未曾分布过的地域 ,并能繁衍后代的过程。植物外来种的入侵可以通过多种途径 :如野生动物、风、水和人类的活动等传播 ,尤其是人类活动的影响使生物入侵的范围、频率和强度超过自然入侵。目前已有部分外来的植物被人们确定为生物污染剂。生物污染剂不同于化学污染剂 ,后者可以随时间而减弱或分解掉 ,而前者则有持久性、倍增性和传播性。有些入侵性的外来植物可以对自然资源造成不可挽救的破坏 ,使经过几千年协同进化的植物、动物、土壤和水分的生态平衡被破坏。当本地植物被外来…     

Invasiveness potential of Miscanthus sinensis: implications for bioenergy production in the United States

Miscanthus sinensis (Anderss.) is a perennial grass species that has been grown widely as an ornamental since the late 1800s and is now being considered for bioenergy production in the United States. With its ability to be grown from seed and tolerate cold climates, this species offers practical advantages over current cultivars of the higher‐yielding hybrid species, M.×giganteus. Yet a large‐scale release of M. sinensis for bioenergy production in colder northern regions could result in new invasions into natural areas. We show, with reference to historical records and data collected in six wild US populations of M. sinensis in 2009, that ornamental varieties of this species have a long history of localized escape in the Eastern United States, primarily within the Appalachian region. To prevent further escape and gene flow, we recommend the development of sterile or functionally sterile varieties of M. sinensis or the restriction of its usage as a donor of genetic material to new sterile cultivars of M. ×giganteus. Other appropriate precautions for new biomass varieties include experimental demonstration of low invasiveness in the target region ahead of commercial production, along with postintroduction stewardship programs.     

北京市建成区绿地植物物种来源分析

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。     

Andropogon gayanus (Gamba Grass) Invasion Increases Fire-mediated Nitrogen Losses in the Tropical Savannas of Northern Australia

Invasive alien grasses can substantially alter fuel loads and fire regimes which could have significant consequences for fire-mediated nutrient losses. The effects of the alien grass Andropogon gayanus Kunth. (Gamba grass) on fire-mediated nutrient losses was evaluated in Australia’s tropical savannas. Losses of macronutrients during fire were determined by comparing the nutrient pools contained in the fine fuel before fire and in the ash after fire. Pre-fire grass nutrient pools were significantly higher in A. gayanus plots than in native grass plots for all nutrients measured (N, P, K, S, Ca, and Mg). Nutrient losses were substantially higher in A. gayanus plots, with 113% higher losses for N, 80% for P, 56% for K, 63 for S, 355% for Ca, and 345% for Mg. However, only losses of N and Mg varied significantly between grass types. A simplified savanna ecosystem nutrient budget estimated that A. gayanus fires led to the net N loss of 20 kg ha⁻¹ y⁻¹. This is a conservative estimate because total fuel loads were relatively low (7.85 t ha⁻¹) for A. gayanus invaded plots leading to a relatively moderate intensity fire (6,408 kW m⁻¹). Higher A. gayanus fuel loads and fire intensities could potentially lead to losses of up to 61.5 kg N ha⁻¹ from the grass fuel. Over the long term, this is likely to lead to depletion of soil nutrients, particularly N, in the already low-fertility tropical savanna soils.     

“973”项目“农林危险生物入侵机理与控制基础研究”简介

2002年12月,国家重点基础研究发展计划("973"项目)"农林危险生物入侵机理与控制基础研究"经科技部批准正式立项,2003年启动。文章主要介绍该项目的立项背景、主要研究内容、研究方案和技术路线、总体研究目标及研究进展。     

北京外来入侵植物刺萼龙葵的生态状况

调查了北京密云县李各庄和小漕村荒草地90个2m×2m草本优势型样方的刺萼龙葵入侵地,分析了样方中各种植物的种类组成和区系特点以及种群的多度、频度和重要值,并结合其生长型、生态优势和竞争关系,评估了北京外来入侵植物刺萼龙葵的生态状况和生态危害风险。结果表明:在多度方面,刺萼龙葵在李各庄群落(共29种植物)中位列第3,在小漕村群落(共51种植物)中位列第5;在频度方面,刺萼龙葵在李各庄群落和小漕村群落中都位列第1;重要值数据表明,刺萼龙葵在李各庄群落和小漕村群落中的综合适应力均最大。综合分析可知,刺萼龙葵在北京的入侵生长尚处于局部危害阶段,但在其范围内已经突破生长瓶颈,成为优势种,同时禾本科、菊科和桑科的一些物种在抗衡刺萼龙葵的进一步扩展上具有一定的潜力。在生态干预策略上,可立足于若干具一定优势的本地物种,在刺萼龙葵发展到单优势种之前对其实行生态更替和铲除。     

中国西南纵向岭谷区外来入侵植物对生物多样性的影响

论述中国西南纵向岭谷区外来入侵植物对生物多样性的影响。中国西南纵向岭谷区是我国生物多样性保护的关键地区。目前,该区域已成为外来植物入侵的重灾区,外来入侵植物种类多达70余种,其中,紫茎泽兰Ageratina adenophora（Eupatoriumadenophorum）、飞机草Chromolaena odorata（Eupatorium odoratum）和肿柄菊Tithonia diversifolia等在该区域危害严重,该区域的生态系统的结构与功能遭受破坏,本地物种面临灭绝,农、林、牧生产乃至区域的生态安全受到威胁。该区域的外来入侵植物的危害居全国之冠。研究该区域的外来入侵植物,揭示其危害规律,遏制其危害速度,最终清除该区域的外来入侵植物,恢复该区域的生态平衡,具有十分重要的现实意义和科学价值。文中详细论述了外来入侵植物对植物物种多样性、植物群落多样性、生态系统多样性、农牧业及林业的影响,最后指出消除和控制外来入侵植物的途径。     

Niche-based modelling as a tool for predicting the risk of alien plant invasions at a global scale

Predicting the probability of successful establishment of plant species by matching climatic variables has considerable potential for incorporation in early warning systems for the management of biological invasions. We select South Africa as a model source area of invasions worldwide because it is an important exporter of plant species to other parts of the world because of the huge international demand for indigenous flora from this biodiversity hotspot. We first mapped the five ecoregions that occur both in South Africa and other parts of the world, but the very coarse definition of the ecoregions led to unreliable results in terms of predicting invasible areas. We then determined the bioclimatic features of South Africa's major terrestrial biomes and projected the potential distribution of analogous areas throughout the world. This approach is much more powerful, but depends strongly on how particular biomes are defined in donor countries. Finally, we developed bioclimatic niche models for 96 plant taxa (species and subspecies) endemic to South Africa and invasive elsewhere, and projected these globally after successfully evaluating model projections specifically for three well‐known invasive species (Carpobrotus edulis, Senecio glastifolius, Vellereophyton dealbatum) in different target areas. Cumulative probabilities of climatic suitability show that high‐risk regions are spatially limited globally but that these closely match hotspots of plant biodiversity. These probabilities are significantly correlated with the number of recorded invasive species from South Africa in natural areas, emphasizing the pivotal role of climate in defining invasion potential. Accounting for potential transfer vectors (trade and tourism) significantly adds to the explanatory power of climate suitability as an index of invasibility. The close match that we found between the climatic component of the ecological habitat suitability and the current pattern of occurrence of South Africa alien species in other parts of the world is encouraging. If species' distribution data in the donor country are available, climatic niche modelling offers a powerful tool for efficient and unbiased first‐step screening. Given that eradication of an established invasive species is extremely difficult and expensive, areas identified as potential new sites should be monitored and quarantine measures should be adopted.     

中国1,334种兰科植物就地保护状况评价

作者通过对中国543个自然保护区内兰科植物数据的分析,对我国1,334种兰科植物的就地保护状况进行了逐一评价。我们根据有记录分布保护区的数量,通过专家咨询的方式,将兰科植物就地保护水平划分为"有效保护"、"较好保护"、"一般保护"、"较少保护"、"保护状况不明"和"未予评价"6个等级。结果发现:有676种兰科植物在自然保护区内得到了不同程度的就地保护,占所评价兰科植物总数的51.9%;但有626种兰科植物保护状况不明,尚未受到就地保护,占总数的46.9%。另外有32种仅分布在香港、澳门和台湾地区,本研究中未予评价,约占总数的2.4%。根据评价结果,就兰科植物就地保护中存在的基础调查不足、受关注程度低、受保护率低等问题进行了深入的讨论,提出5条有针对性的建议对策:(1)加强兰科植物的调查监测;(2)提高兰科植物的保护级别与受关注程度;(3)进一步完善兰科自然保护区建设;(4)规范自然保护区综合科学考察;(5)定期评价我国兰科植物保护成效。     

Habitat Invasibility and Dominance by Alien Annual Plants in the Western Mojave Desert

Patterns of habitat invasibility and alien dominance, respectively measured as species richness and biomass of alien annual plants, were evaluated in association with four habitat factors at the Desert Tortoise Research Natural Area (DTNA) in the western Mojave Desert, USA. Habitat factors varied in levels of disturbance outside (high) and inside (low) the DTNA, and in levels of soil nutrients in washlet (high) and hummock (low) topographic positions, in Larrea-north (high), Larrea-south (medium), and interspace (low) microhabitats near creosote bushes (Larrea tridentata), and during 1995 when rainfall was 207% (high) and 1994 when rainfall was 52% (low) of the long-term average. Dominant alien plants included the annual grasses Bromus rubens, Bromus trinii, and Schismus spp., and the forb Erodium cicutarium. Species richness and dominance of alien annual plants were slightly higher where disturbance was high, and much higher where soil nutrients were high. B. rubens and B. trinii were most dominant in washlets and in the Larrea-north microhabitats during both years. These two species evolved in mesic ecosystems, and appeared to be particularly limited by soil nutrients at this site. Schismus spp. and E. cicutarium were also most dominant in washlets, but their dominance varied between interspaces in 1994 and the Larrea-south microhabitat in 1995. Monitoring to detect the invasion of new annual plants should focus on regions of high rainfall and nitrogen deposition and on washes and beneath-canopy microhabitats. The ecological range of each alien species should be evaluated separately, because their evolutionary origins may greatly affect their patterns of invasion and dominance in the Mojave Desert. This revised version was published online in July 2006 with corrections to the Cover Date.     

Resource-Ratio Theory and the Control of Invasive Plants

There have been relatively few tests of resource-ratio theory in terrestrial systems. Additionally, resources are known to be an important factor determining the success of invasive species. Here I discuss how the study by Newingham and Belnap (pp. 29–40, this issue) tests predictions of resource-ratio theory and how they apply it to questions of invasion by Bromus tectorum in a terrestrial grassland.     

A New Approach Toward Natural and Anthropogenic Risk Assessment of Gas Power Plants

The current study focuses on identification and prioritization of the most important risks affecting a gas power plant located in southern Iran that was selected as a case study. After identifying risky activities, plant operations, and natural disasters, a Delphi questionnaire was prepared to specify crisis and accident-prone centers that could lead to the plant's destruction. After analyzing the questionnaires, the final criteria were determined. Subsequently, multi-criteria decision-making methods including the technique for order preference by similarity to ideal solution (TOPSIS) and analytical hierarchy process (AHP) were applied to prioritize the identified criteria. The relative weights of the criteria were calculated using the eigenvector method in the environment of MATLAB and Expert Choice. In some cases, there was no correlation between the obtained results, resulting in a novel integrated technique consisting of three methods: average, Borda, and Copeland were used to reach a consensus for prioritizing the criteria. The risk assessment results indicate that gas and oil pipes, dust storm, and terrorism have the first to third priorities among the other risks. Some strategies are proposed to control and mitigate the identified risks.     

Ten Years of the Relative Risk Model and Regional Scale Ecological Risk Assessment

It has been 10 years since the publication of the relative risk model (RRM) for regional scale ecological risk assessment. The approach has since been used successfully for a variety of freshwater, marine, and terrestrial environments in North America, South America, and Australia. During this period the types of stressors have been expanded to include more than contaminants. Invasive species, habitat loss, stream alteration and blockage, temperature, change in land use, and climate have been incorporated into the assessments. Major developments in the RRM have included the extensive use of geographical information systems, uncertainty analysis using Monte Carlo techniques, and its application to retrospective assessments to determine causation. The future uses of the RRM include assessments for forestry and conservation management, an increasing use in invasive species evaluation, and in sustainability. Developments in risk communication, the use of Bayesian approaches, and in uncertainty analyses are on the horizon.     

Practical Issues in the Use of Probabilistic Risk Assessment

Probabilistic risk assessment (PRA) represents an important step in the evolution of risk assessment methodology to assist decision-making at hazardous waste sites. Despite considerable progress in the development of PRA techniques, regulatory acceptance of PRA has been limited, in part because a number of practical issues in its use must yet be resolved. A recent workshop on PRA identified several areas to be addressed, including the need for: (1) better demonstration of the value of PRA in risk management; (2) PRA training and education opportunities; (3) the development of technical criteria for acceptability of a PRA; (4) policy decisions on acceptable risk distributions; (5) ways to deal with risk communication issues; and (6) a variety of technical issues, including ways to include estimates of variability and uncertainty associated with toxicity values. Solutions to many of these issues will require better dialog between risk assessors and risk managers than has existed in the past.