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1.
    
Australia and South Africa have a long history of sharing successful biocontrol agents for cactus weeds but other countries, such as Namibia, could also benefit. There are four biological control agents that are widely utilised in South Africa and/or Australia for the control of 10 invasive alien Cactaceae in Namibia.  相似文献   

2.
During the analysis of alien and invasive flora of Europe, as a threat to biodiversity, data for Croatia were missing. The aim of our research was to analyse distributional patterns and range size of all invasive alien plants (64) for the state area (57,000 km2). They were detected on 49% of the state territory, averaging five taxa per 35 km2. The greatest number of invasive plants (> 30 per grid cell) was recorded in the major urban centres, increasing in the south-east direction and reflecting positive correlation with temperature and negative with altitude. The most endangered areas are in the Mediterranean region, especially on islands. The number of invasive plants increased with habitat diversity and almost 75% of all sites with invasive plants are located within a few habitats with direct anthropogenic influence. The results should provide a reliable regional and global basis for strategic planning regarding invasive alien plants management.  相似文献   

3.
水生植物引种的生态安全评价   总被引:2,自引:0,他引:2       下载免费PDF全文
随着水生植物的大量应用,水域环境的生态安全越来越受到关注。水生植物入侵具有一定的生物学、区系地理、生态位和生境特征,对水生植物的生态安全评价可在一定程度上防止水生植物引种的盲目性。该文针对来自水生外来入侵植物的生态安全威胁,分析了水生外来入侵植物的入侵特征及其危害,提出了水生植物引种的生态安全评价的内容、程序、指标体系和方法。  相似文献   

4.
Since 1969, weed biological control (WBC) practitioners have met at a series of 14 International Symposia on Biological Control of Weeds (ISBCWs). These gatherings have had no societal organization, thus the published proceedings are the main source of information on the recent history of this sub-discipline. Only 1144 individuals (mostly entomologists and plant pathologists) have ever attended an ISBCW: 338 (29.6%) have been at more than one symposium, bringing the total number of attendees to 1972. About 75% of these have come from the main WBC implementing nations, the USA, Australia, South Africa, Canada, and New Zealand. The present analysis of ISBCW attendees has led to estimates that the global WBC research and development effort over the last 50 years has been the domain of about 450–550 WBC practitioners. WBC is presently beleaguered in the USA, Canada and Australia and attendance figures at recent ISBCWs are in decline. A case is made that these trends are largely due to the negative perceptions and damaging consequences of two decades of debates that have exaggerated the risks of non-target impacts and impeded progress in WBC. Further procrastination seems inevitable but in the interests of agriculture and conservation, WBC will need to be deployed more extensively if invasive alien (i.e., introduced, non-indigenous) plants are to be suppressed. In this context, the recent releases of WBC agents in Europe are signal events. It is mooted that a more formal and structured organization for the ISBCW meetings and perhaps a ‘rebranding’ of the sub-discipline is needed to champion and rekindle the practice of WBC.  相似文献   

5.
Invasive Alien Species (IAS) have been emerging as the second biggest threat to global biodiversity after habitat destruction. They intervene in environmental services offered by ecosystems and negatively impact flood control, water supply, water assimilation, nutrient recycling, conservation and regeneration of soils. Due to these threats better IAS management is needed for a biodiversity rich nation like India. To date very few examples of successful eradications of IAS exist. However, some studies have pointed out several economic benefits rendered by IAS which include fodder, food, manure, bio-fuels and medication values which make them interesting from a commercial point of view which could led to an increase in demand for these IAS species by certain industries (pharmaceutical, botanical sectors) in the future driving IAS to the verge of extinction in the wild this way. This review presents an overview of IAS existing in India and their possible medicinal potential which could, if proven useful, lead to an alternative way of controlling the proliferation of IAS and to conserve nature diversity.  相似文献   

6.
We provide an updated inventory of the non-native flora of the Italian island of Sardinia, including accepted names, family, synonyms, biological form, fruit type, introduction pathway and native origin. This inventory was performed by reviewing the available literature and conducting dedicated field surveys across the entire island. The inventory catalogues 931 non-native taxa, including 31 cryptogenic species, 901 species, 14 subspecies, 13 varieties, two forms and one cultivar. We utilised the position on the introduction–invasion continuum concept and meta-population criterion to further label each species. Based on these frameworks, the non-native flora of Sardinia can be divided into 274 casual, 169 naturalised, 19 invasive, 440 exclusively planted and 29 unobserved after 1950. There are 204 archaeophytes and 727 neophytes. The majority of the non-native species (791) were introduced to the island voluntarily, and 140 species were introduced accidentally. The present inventory identifies 72 additional non-native taxa not previously reported in the literature.  相似文献   

7.
[目的]了解湛江市外来入侵植物的种类特征、生活型、起源和危害情况等,对制定预防和控制管理措施提供参考。[方法]以野外调查为主,结合文献资料、网络资源以及标本数据,确定湛江市外来入侵植物的种类、生活型、原产地、引入途径,并进行评估及划分危害等级。[结果]湛江市现有外来入侵植物共112种(含变种),隶属于37科89属,其中,菊科(21种)、禾本科(13种)和豆科(13种)为种类较多的3个科,三者合计占湛江市外来入侵植物总种数的41.96%。湛江市外来入侵植物中以草本植物居多(98种),占入侵植物总数的87.50%。入侵植物主要来源于美洲,共82种,占总种数的73.21%;且55.36%(62种)的入侵植物为有意引入。从危害等级看,外来入侵植物中恶性入侵种(1级)23种,严重入侵种(2级)35种,局部入侵种(3级)21种,一般入侵种(4级)15种,有待观察种(5级)18种。[结论]湛江市的外来入侵植物种类繁多,这与湛江独特的地理位置以及日趋频繁的人类活动息息相关,应当加强监管与防范,及时对外来物种进行治理。  相似文献   

8.
任芝坤  孙燕  黄伟 《植物科学学报》2023,348(5):626-635
全球变化不仅会造成环境中资源的稳态变化,还会引起资源的波动性变化。资源变化影响外来植物的成功入侵,但是资源的波动性变化对入侵植物地上、地下生物量分配模式的影响仍不清楚。本研究以入侵植物小蓬草(Erigeron canadensis L.)为研究对象,设置了4种不同的营养添加方式(恒定低、恒定高、多个小脉冲和单个大脉冲)探究外来入侵植物如何响应环境中资源的波动性变化。结果显示:(1)相比于低营养条件,高营养条件显著提高小蓬草的地上、地下生物量、叶绿素含量以及比叶面积,但是根冠比却表现出显著的下降趋势;(2)在所有的高营养处理中,营养脉冲也会影响小蓬草的生物量、根冠比和比叶面积;(3)单个大脉冲会显著抑制小蓬草的地上生物量,促进地下生物量;(4)多个小脉冲对小蓬草的总生物量有一定的促进作用,并显著增加了比叶面积。研究结果说明,环境中资源波动的变化形式会改变入侵植物的地上-地下生长策略从而影响其生长特征,但是资源的波动性变化并没有显著促进外来入侵植物的生长。  相似文献   

9.
    
An important aspect of conservation is to understand the founding elements and characteristics of metacommunities in natural environments, and the consequences of anthropogenic disturbance on these patterns. In natural Amazonian environments, the interfluves of the major rivers play an important role in the formation of areas of endemism through the historical isolation of species and the speciation process. We evaluated elements of metacommunity structure for Zygoptera (Insecta: Odonata) sampled in 93 Amazonian streams distributed in two distinct biogeographic regions (areas of endemism). Of sampled streams, 43 were considered to have experienced negligible anthropogenic impacts, and 50 were considered impacted by anthropogenic activities. Our hypothesis was that preserved (“negligible impact”) streams would present a Clementsian pattern, forming clusters of distinct species, reflecting the biogeographic pattern of the two regions, and that anthropogenic streams would present random patterns of metacommunity, due to the loss of more sensitive species and dominance of more tolerant species, which have higher dispersal ability and environmental tolerance. In negligible impact streams, the Clementsian pattern reflected a strong biogeographic pattern, which we discuss considering the areas of endemism of Amazonian rivers. As for communities in human‐impacted streams, a biotic homogenization was evident, in which rare species were suppressed and the most common species had become hyper‐dominant. Understanding the mechanisms that trigger changes in metacommunities is an important issue for conservation, because they can help create mitigation measures for the impacts of anthropogenic activities on biological communities, and so should be expanded to studies using other taxonomic groups in both tropical and temperate systems, and, wherever possible, at multiple spatial scales.  相似文献   

10.
[目的] 完善江西省外来植物本底调查数据,为江西省外来入侵植物的预防和预警机制构建提供依据。[方法] 通过文献、标本研究以及野外实地调查,对江西外来植物种类、原产地、生活型、引入途径、引入时间、在各地级市的分布情况以及外来入侵植物的种类进行分析、探讨。[结果] 江西省外来植物有106科407属599种:菊科最多(85种,14.19%),其次是豆科(52种,8.68%),10种以下的科有91个,占总科的85.85%;主要源于美洲(49.25%),其次是亚洲(20.80%),欧洲第三(13.81%),地中海和大洋洲较少;外来植物中草本植物种类最多,乔木次之;大部分被用于观赏、饲料、药物等有意引入。江西省的外来入侵植物有53科168属267种;九江、赣州和南昌由于地理位置优越及经济地位突出被入侵较严重。[结论] 江西省外来植物种类丰富,引入途径多样,入侵物种较多。建议构建风险评价系统,加强外来植物监管监测,科学引种;制订和更新外来植物防控的具体政策法规;同时,加大入侵危害宣传,及时防控和阻止外来植物逃逸入侵对本省生态环境造成侵害。  相似文献   

11.
    
A key scientific challenge relating to the threat of invasive plants on agriculture at the region level is to understand their adaptation and evolution in functional traits. Leaf functional traits, related to growth and resource utilization, might lead to adaptation of invasive plants to the geographical barriers (region or elevation). In the field experiment, we discussed the effects of region and elevation on leaf functional traits on invasive plant Erigeron annuus in farmland habitats in China. We compared leaf size, coefficient of variation (CV) of leaf traits, and fluctuating asymmetry (FA) of E. annuus from three regions (east vs. center vs. west) and two leaf types (vegetative vs. reproductive leaf), and from nine elevations (980–2100 m) in the west region of China. Our results indicated region and leaf type influenced leaf functional traits, and leaf size was significantly higher and CV of leaf traits and FA in reproductive leaves were significantly lower in the east region than in the west and center regions. Elevation and leaf type affected leaf functional traits, and leaf size was significantly higher and CV of leaf traits in reproductive leaves were significantly lower in moderate elevation. E. annuus has higher leaf size and developmental stability (lower CV and FA) in the eastern region due to the longer adaptation period. Therefore, leaf functional traits play an important role in the adaptation of different longitudes and elevations. It can also facilitate the understanding of the invasiveness and adaptation of leaf traits of invasive plants in the agricultural ecosystem during their spread process in China.  相似文献   

12.
中国外来入侵植物区系组成的大尺度格局及其气候解释   总被引:4,自引:0,他引:4  
外来入侵物种的空间分布格局及其影响因子的研究是外来物种管理和控制的基础。本研究利用文献数据和气候资料,探讨了中国外来人侵植物(属)区系组成的大尺度格局及其与气候因子之间的联系。从植物区系的总体构成来看,热带区系成分所占比重较大,其次为温带成分和世界分布成分,说明研究区域内外来人侵植物主要起源于热带地区,其次为温带地区。从空间格局来看,从南到北,热带区系成分所占比重呈递减趋势,而温带区系成分所占比重则呈递增趋势。这说明,在南部区域,外来入侵植物更多的来自于热带地区,但在北部区域,来自于温带地区的外来入侵植物可能占据主导地位。热量水平显著影响外来入侵植物的空间格局,随着热量水平的提高,热带区系比重呈递增趋势,而温带区系成分所占比重则呈递减趋势,这可能与不同区系成分植物的生态特性有关。  相似文献   

13.
We determined the complete mitochondrial genome sequences of two haplotypes of the smallmouth bass, Micropterus dolomieu; individuals used in the analysis were collected from nonindigenous populations in Japan. Both genomes comprised 16,488 bp, with genome contents and gene orders being identical to those of other teleost fishes. A previous study revealed that the Japanese smallmouth bass had only two haplotypes, and the present study revealed that the complete mitochondrial DNA (mtDNA) sequences of the haplotypes differed in only one nucleotide difference. The low genetic diversity in the mtDNA of the smallmouth bass individuals in our study and the results of the mtDNA sequence comparison between the Japanese and the North American individuals suggested that the fish had been transplanted from a fish farm with a low-diversity stock.  相似文献   

14.
    
Yan Sun  Aline Junod 《植被学杂志》2017,28(6):1250-1259
  相似文献   

15.
【背景】广东省是我国遭受外来生物入侵最严重的地区之一,许多外来水生动物在广东省的河流均有分布,但有关其具体分布和数量缺乏系统研究。【方法】通过野外调查的方式对广东省鉴江、韩江、潭江、西江、北江、东江等水系的外来水生动物的分布和数量进行了初步调查,并对调查到的外来水生动物的生态学特征和入侵机制进行了初步研究。【结果】共调查到13种外来水生动物,包括巴西龟、尼罗罗非鱼、莫桑比克罗非鱼、奥利亚罗非鱼、下口鲶、革胡子鲶、食蚊鱼、麦瑞加拉鲮、露斯塔野鲮、斑点叉尾鮰、大口黑鲈等11种脊椎动物和福寿螺、克氏原螯虾2种无脊椎动物;其中以福寿螺、巴西龟和3种罗非鱼的分布最为广泛。【结论与意义】几种外来水生生物主要通过水产养殖、观赏渔业和生物防治引种入侵;典型的\"R\"策略者、对环境具有较强耐受力的生物、杂食性鱼类更容易成功入侵。  相似文献   

16.
在简要讨论外来植物相关定义的基础上, 对中国外来归化植物的调查和编目现状进行了概述; 并对近年发表的两篇文章中外来归化植物数据进行了订正。  相似文献   

17.
紫茎泽兰广泛入侵中国西南地区,研究结果表明化感作用是其入侵的重要武器,但其化感作用的途径并不十分清楚。本研究中,我们发现紫茎泽兰可以通过多种途径对两种栽培植物大麦和玉米的生长产生化感作用,这些途径包括了叶挥发物、叶淋溶物以及根分泌物。并且在紫茎泽兰幼苗早期就可以检测到这些化感作用。然而,没有实验证据表明紫茎泽兰落叶的微生物降解物对两种测试植物具有化感作用。  相似文献   

18.
入侵植物紫茎泽兰化感作用及其途径研究   总被引:1,自引:0,他引:1  
紫茎泽兰广泛入侵中国西南地区,研究结果表明化感作用是其入侵的重要武器,但其化感作用的途径并不十分清楚。本研究中,我们发现紫茎泽兰可以通过多种途径对两种栽培植物大麦和玉米的生长产生化感作用,这些途径包括了叶挥发物、叶淋溶物以及根分泌物。并且在紫茎泽兰幼苗早期就可以检测到这些化感作用。然而,没有实验证据表明紫茎泽兰落叶的微生物降解物对两种测试植物具有化感作用。  相似文献   

19.
云南种子植物中的新入侵和新分布种   总被引:2,自引:0,他引:2  
报道了两个云南的新入侵植物及两个新分布种,分别是光冠水菊和细叶旱芹及俯垂粉报春和针叶韭,并对新入侵植物的危害性及防治措施等进行了初步讨论。  相似文献   

20.
A list of non-native phytophagous insects and mites on woody plants (trees, shrubs, vines) in Canada was compiled using information from literature and input from taxonomists. The 419 recorded species include Hemiptera (53% of species), Lepidoptera (22%), Coleoptera (13%) and Hymenoptera (9%). Almost all species originate from the Palearctic, especially Europe, reflecting historical trade patterns. About 41% of species were directly introduced to Canada from countries of origin, and the remainder spread from the United States of America (USA) after initial establishment there. Major ports on the east and west coasts, on Lake Erie and Lake Ontario are the main points of entry for exotic species directly introduced, and southern British Columbia (BC), Ontario (ON) and Quebec (QC) are the major points of entry for species spreading from the USA. Consequently, BC, ON, QC and Nova Scotia have the highest diversity of non-native species, and the prairie provinces and northern territories have the lowest. The extent of the distribution of individual species is related to length of time in Canada, number of introductions and dispersal abilities. Almost all native woody plant genera in Canada have been invaded by exotic phytophages. The large majority of phytophages occur on angiosperms. Woody plant genera with the largest distribution, highest species diversity and highest local abundances tend to host the greatest number of non-native species, including Picea, Pinus, Malus, Prunus, Salix, Betula, Quercus, Pyrus and Populus. The arrival rate of species in Canada increased from the late nineteenth century until about 1960, and declined rapidly thereafter. Quarantine legislation enacted in the USA in 1912 and in Canada in 1976 seems to have reduced the rate of insect invasion. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

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