海洋外来物种入侵生态学研究

海洋外来物种入侵已成为最为严重的全球性环境问题之一。海洋生态系统类型多样、环境复杂,其生物入侵的监测、控制与管理难度相对较大。我国对陆地外来生物的入侵已开展了较为深入的研究,但对于海洋外来生物的入侵研究仍处于起步阶段,对其入侵监测、入侵机制、入侵危害的程度以及防治等问题缺乏基础数据。本文在分析国内外海洋外来生物入侵现状的基础上,概述其入侵生态学研究形势及相关成果,包括海洋外来物种的入侵途径、入侵过程、入侵生态效应以及全球变化对入侵的影响等。海洋外来生物的入侵可能对海洋生态系统造成直接或间接的影响,如种间竞争破坏生态环境、与土著种杂交造成遗传污染、病原生物及有毒藻类导致海洋生态灾害加剧等。此外,从政策和法规、入侵风险评估、监测和公共宣传教育、生物信息系统和有效管理机制等方面提出对我国海洋外来物种入侵的防治策略。本研究为我国海洋外来物种的进一步研究提供了参考。     

外来种入侵的生物学与生态学基础的若干问题

外来物种的入侵及其所造成的危害已越来越为人们所认识。一个外来物种入侵一个新的生境无疑要具备一定的条件 ,尽管目前对这种条件的研究还只是初步的。首先从其自身来说 ,需要有足够的入侵性 ,这可以认为是入侵种的生物学基础 ,可能表现为具有多倍性、一定的遗传变异、杂合性或表型可塑性 ,以及不同的交配系统等 ;其次一个物种的入侵成功还取决于入侵生境的可入侵性 ,这可以认为是入侵种的生态学基础 ,而新的种间关系的形成 ,尤其是入侵种与其他种类的互惠共生关系的建成是关键。本文主要介绍了有关入侵种的生物学和生态学基础中的一些最新进展 ,希望有助于我国学者对相关研究内容的开展以及对有害外来种入侵的防治     

我国外来入侵生物防控现状、问题和对策

外来物种入侵已经威胁全球多个国家和地区,严重影响农林牧渔业生产,威胁生态系统稳定,是当前全球生物多样性丧失的主要原因之一,开展入侵物种防控已成为生物多样性保护与农业绿色发展的重点工作。我国已经成为全球遭受生物入侵威胁与损失最为严重的国家之一,截至2018年底,入侵我国的外来物种有近800种,已确认入侵农林生态系统的有638种,全国31个省（区、市）均有外来生物入侵发生并带来危害,半数以上县域都有入侵物种分布,几乎涉及所有类型的生态系统。本文对全球主要发达国家外来入侵物种发生情况及防控进行梳理发现,从国家层面立法开展外来入侵生物防控成为主流,制定长期防控战略并增加投入是入侵物种防控成功的关键。近些年,我国在外来入侵物种防控方面初步建立了工作机制,发布了重点管理外来入侵物种名录,完成了重点入侵物种的调查监测,开展了局部地区的防控措施,积极推动立法工作。根据国外生物入侵防治经验与我国实际情况,本研究提出我国外来入侵物种防控对策建议,包括加强法制建设、开展本底调查和启动重大防控工程等,为我国外来侵入生物的防控提供借鉴。     

中国外来入侵生物的空间分布格局及其影响因素

不同地理区域影响生物分布格局的因子不同,对外来入侵物种也是如此。在区域尺度上分析外来入侵生物的空间分布格局及其影响因子对预测生物入侵的影响及入侵种的控制管理具有重要意义。本研究应用中国外来入侵物种数据库、自然环境数据库和社会人文环境数据库,分析了我国外来入侵动植物的空间格局;并运用主成分分析（PCA）和典范对应分析（CCA）探讨了自然环境和人类活动等因素对外来入侵动植物分布格局的影响;同时研究了外来入侵物种多样性与本地物种多样性之间的关系。结果表明,我国现有外来入侵动物138种、入侵植物384种,其数量和密度都呈现出由东南沿海向西北内陆减少的趋势,且入侵动物和入侵植物空间格局基本一致;降水（MAP）是决定我国外来入侵动植物分布格局的主要自然环境因子,国民生产总值（GDP）是主要社会经济影响因子。在全国尺度上,外来入侵物种多样性与本地物种多样性之间呈显著的正相关关系,但地域间存在较大差异。不同区域外来入侵物种与本土物种多样性的相关关系表现出不同,与研究尺度有密切关系。     

维护我国生态安全,防范外来物种入侵的几点思考

随着全球经济一体化,国际贸易和旅游业的快速发展,外来物种入侵现象日益加剧,对我国生态安全和生物多样性保护构成了极大的威胁,加强外来入侵物种的防范和管理已迫在眉睫。本文分析了我国外来物种入侵的途径、入侵特征以及外来入侵物种对我国造成的危害,探讨了防范外来入侵物种的对策。     

“世界100种恶性外来入侵物种”在我国大陆的入侵现状

[目的] 明确世界自然保护联盟公布的“世界100种恶性外来入侵物种”在我国大陆发生分布现状,为我国制定外来入侵物种管控对象和分级管理对策提供依据。[方法] 基于在线数据库系统、文献报道以及外来入侵物种本底调查结果,采用分类统计方法,对物种的分类地位、原产地、在我国的入侵状态及其所在的生态系统进行分析。[结果] 世界100种恶性外来入侵物种已有82种在我国发生分布,包括本地种33种、外来入侵种32种、外来非入侵种16种,以及未明确入侵状态1种。其中,32种外来入侵种包括陆生无脊椎动物8种、哺乳动物2种、鱼类2种、两栖动物1种、爬行动物1种、水生无脊椎动物2种、陆生植物9种、水生植物4种、真菌1种、卵菌1种和病毒1种。以上物种主要分布在东南沿海地区和西南地区,而较少分布在西北地区和东北地区;约75%物种分布在农田、城镇、森林和湿地4类生态系统。[结论] 建议外来入侵物种管理部门重点关注尚未在国内发生分布的18种潜在外来入侵物种,并列入国家外来入侵物种相关管理对象,严防其传入与扩散;严密监控国内已发生且具有潜在危险的外来物种,防止其向可能入侵的生态系统边缘扩散;继续对在国内已发生的外来入侵种实施区域性分级控制管理措施。     

外来入侵物种管理中的排序体系研究进展

外来物种入侵是继生境破坏之后的第二大世界性的环境问题, 如何实现外来入侵物种分级, 对其进行有效管理是一个世界性的难题。研究总结了国内外外来入侵物种的排序体系, 从三个方面归纳了目前的排序系统: 1)针对所有入侵以及潜在入侵物种开展综合风险评估, 以此为基础提出防控管理清单; 2)针对已建群的外来入侵物种, 围绕不同管理目标进行入侵物种的排序, 包括以降低外来入侵物种对生物多样性影响为目的的外来植物排序、以生物防治为控制手段的外来物种排序、基于土地利用的种群管理排序; 3)针对区域管理提出外来入侵物种分区管理。认为外来入侵物种的入侵性、生态危害、分布范围、潜在分布和控制技术是实现排序的关键因素, 指标的选择与确定依赖于管理目标的设定。我国亟需确定外来入侵物种的优先控制区域, 并针对不同优先控制区域内外来入侵物种开展排序工作。     

Bacillus promotes invasiveness of exotic Flaveria bidentis by increasing its nitrogen and phosphorus uptake

芽孢杆菌通过提高黄顶菊对氮和磷的吸收促进外来黄顶菊的入侵 外来植物入侵对土壤芽孢杆菌(Bacillus)多样性的影响及芽孢杆菌在外来植物入侵中的作用目前尚不清楚。黄顶菊(Flaveria bidentis)是入侵中国的有害杂草,狗尾草(Setaria viridis)是黄顶菊入侵地常见的伴生植物种。本研究利用野外大田试验和温室盆栽试验,比较黄顶菊和狗尾草根际土壤芽孢杆菌群落结构的差异,以及黄顶菊和狗尾草根际土壤芽孢杆菌对黄顶菊竞争生长的影响。野外大田试验包括黄顶菊 单种、黄顶菊和狗尾草混种、狗尾草单种3个处理。利用16S rRNA基因测序技术研究了不同处理两种植物 根际土壤芽孢杆菌的多样性,获知黄顶菊根际土壤聚集的优势芽孢杆菌;利用温室盆栽试验探究优势芽孢杆菌对黄顶菊竞争生长的影响。研究结果表明,黄顶菊和狗尾草根际土壤芽孢杆菌多样性差异显著,其中耐寒芽孢杆菌是黄顶菊和狗尾草根际土壤聚集的优势芽孢杆菌,但是黄顶菊根际土壤中耐寒芽孢杆菌相对丰度显著高于狗尾草根际土壤耐寒芽孢杆菌的相对丰度。接菌试验表明,与狗尾草根际土壤中的耐寒芽孢杆菌相比,黄顶菊根际土壤聚集的耐寒芽孢杆菌提高了黄顶菊体内氮和磷的水平。总之,黄顶菊入侵改变了根际土壤芽孢杆菌的群落结构,黄顶菊根际土壤聚集的耐寒芽孢杆菌通过提高黄顶菊植株体内氮、磷水平来促进黄顶菊的生长。     

我国部分国家级自然保护区外来入侵物种的分布概况

基于我国53 个国家级自然保护区外来入侵植物调查与24 个国家级自然保护区外来入侵动物调查数据, 分析了外来入侵物种种类、分布状况等。调查共发现外来入侵物种201 种, 包括入侵植物176 种和入侵动物25 种。52.08%的外来入侵植物已入侵到我国国家级自然保护区, 30 个国家级自然保护区受外来入侵物种影响显著, 52 个国家级自然保护区分布有环保部公布的外来物种。云南纳板河流域国家级自然保护区外来入侵物种数目最多, 为61 种; 小蓬草(Erigeron canadwnsis)在国家级自然保护区中的出现频率最高, 为0.736。外来入侵物种已严重威胁我国自然保护区的生态安全, 亟需对保护区的外来入侵物种采取相应的防控措施, 推进外来入侵物种管理成为保护区管理工作的基本内容。     

苋科(广义)入侵植物墙生藜在中国的新记录

外来物种的归化和入侵对全球环境和社会发展造成了严重影响，已成为当今各国生物多样性管理和生态保护中所面临的全球性问题。我国是遭受外来入侵危害最为严重的国家之一，在外来物种入侵的预警、管理和治理等方面形势严峻。基于野外调查和文献研究，该文报道了苋科(广义)入侵植物墙生藜[Chenopodiastrum murale(L.) S. Fuentes, Uotila&Borsch]在中国的新记录。墙生藜原产于地中海地区，现已扩散到欧洲、美洲、非洲和大洋洲的40多个国家，是一种危害较大的外来入侵植物，同时也是我国海关和检验检疫部门明确规定禁止入境的检疫性有害生物，现于云南省昆明市呈贡区发现该外来入侵植物。该文对其形态特征进行了详细描述，简要介绍了其分类历史，并提供了可供鉴定比对的野外生态照片；此外，对墙生藜可能的传入途径进行了分析，对其危害和风险作了简要评估。该物种的新发现说明我国外来入侵生物的本底调查还存在不足。     

Status, invasiveness and environmental threats of three tropical American invasive weeds (Parthenium hysterophorus L., Ageratum conyzoides L., Lantana camara L.) in India

Invasive weeds have threatened the integrity of ecosystems throughout the world. They affect not only the species diversity of native areas but also their biological integrity. In India, a number of invasive exotic weeds have been reported but some viz. Parthenium hysterophorus, Lantana camara and Ageratum conyzoides, especially those from tropical America are troublesome and have caused adverse ecological, economic and social impact. These weeds can be seen growing in different landscapes but are luxuriantly localized in unattended forests and cultivated areas. Parthenium hysterophorus (Asteraceae, commonly known as congress grass) is perhaps the most troublesome and noxious weed of urban and rural India. Besides rapidly colonizing areas replacing the native vegetation, it is also known to cause a number of human health problems such as skin allergy, rhinitis and irritation to eyes of the residents in the vicinity. Likewise, it causes fodder scarcity in addition to being unpalatable and toxic to livestock. Lantana camara (Verbenaceae), another serious tropical American pest, has encroached upon large areas of land, especially the forests where it has virtually replaced the forest floor vegetation and reduced tree growth. Also because of its bushy and spreading type of growth it obstructs forest operations. The third weed, Ageratum conyzoides (Asteraceae, Billy goat weed) has invaded agricultural fields. It interferes with crops and causes yield reductions of major staple crops of India. When it invades rangeland areas, it out competes native grasses causing scarcity of fodder. These weeds have similar growth strategies such as fast growth rates, short life-cycles, greater reproductive potential, high competitive abilities and allelopathy that make them successful invaders of native habitats. Mechanical, chemical, biological and cultural control tactics have failed individually, though integrated approaches combining all these approaches along with community participation and proper land management have been relatively successful. This paper presents various aspects of biology, ecology, hazards and control measures of these weeds.     

Utilization of the Exotic Weed Pluchea odorata (Asteraceae) and Related Plants by the Introduced Biological Control Agent Acinia picturata (Diptera: Tephritidae) in Hawaii

The flower-head feeding fly Acinia picturata (Diptera: Tephritidae) was deliberately introduced from Mexico into Hawaii in 1959 for biological control of the exotic weed Pluchea odorata (Snow) (Asteraceae). Neither field efficacy nor possible non-target effects of the fly have been evaluated in the 40 years since the introduction. We assessed the impact of the fly on both its target host and on seven non-target plant species. The impact on the target weed was limited, with only 5-13% of the developing seeds in P. odorata flowerheads being destroyed by larval feeding. We did not detect any host range expansion of A. picturata onto flowerheads of two exotic or 5 endemic non-target plant species in the family Asteraceae.     

外来杂草入侵的化学机制

由外来杂草入侵引发的严重生态和经济问题已倍受关注,外来杂草在新生境成功入侵,除了具备一些基本的生物生态学特征外,还应具备一些特有的入侵机制,阐明外来杂草的各种入侵机制可以为入侵杂草的预测和控制提供科学依据。外来杂草只有在新生境中与原产地生物种间的相互作用中取得优势,才能定植并扩增种群而成功入侵．在这些外来杂草和原产地生物种间的相互作用关系中,化学关系是不可忽视的方面．目前研究已经证实：植物的化感作用在外来杂草成功入侵中发挥着重要的作用．事实上,植物也可以通过合成和释放特定的化学物质防御或抑制新生境的动物、植物和微生物．外来杂草入侵的化学机制涉及到植物化学生态学的各个方面。因此,外来杂草的化学生态学特征应作为入侵种预测的重要指标之一,外来杂草入侵的化学机制应是今后重要的研究方向。     

Integrating Management Techniques to Restore Sites Invaded by Mile‐a‐Minute Weed,Persicaria perfoliata

Efforts to suppress an invasive weed are often undertaken with the goal of facilitating the recovery of a diverse native plant community. In some cases, however, reduction in the abundance of the target weed results in an increase in other exotic weeds. Mile‐a‐minute weed (Persicaria perfoliata (L.) H. Gross (Polygonaceae)) is an annual vine from Asia that has invaded the eastern United States, where it can form dense monocultures. The host‐specific Asian weevil Rhinoncomimus latipes Korotyaev (Coleoptera: Curculionidae) was first released in the United States in 2004 as part of a classical biological control program. At three sites invaded by mile‐a‐minute weed, biological control was integrated with pre‐emergent herbicide use and two densities of native plantings. After 2 years, native plant cover differed significantly and was greater than 80% in the plots with plantings and pre‐emergent herbicide but less than 30% in the planting treatments without herbicide. Where mile‐a‐minute cover decreased at the two sites with the greatest pressure from exotic plants, plots were dominated by another exotic weed, Microstegium vimineum (Trin.) A. Camus, Japanese stiltgrass. The combination of biocontrol, pre‐emergent herbicide, and revegetation with native plants suppressed mile‐a‐minute weed, prevented invasion by Japanese stiltgrass, and increased the abundance of native plants. The selection of the management strategies used to control mile‐a‐minute weed determined the extent of recovery of the native plant community.     

Native versus exotic community patterns across three scales: Roles of competition,environment and incomplete invasion

Three fundamental, interrelated questions in invasion ecology are: (1) to what extent do exotic species outcompete natives; (2) are native and exotic communities functionally similar or different; and (3) are differences in biogeographic patterns in native and exotic communities due to incomplete invasions among exotics? These questions are analogous to general questions in community ecology regarding the relative roles of competition, environmental response and dispersal limitation in community assembly. We addressed each of these questions for plant communities in discrete meadow patches, using analyses at three scales ranging from the landscape to microsites. A weak positive relationship between native and exotic species richness in microsites, and a predominance of positive correlations in abundance among native and exotic species pairs suggest that competition has been less important than other factors in determining native versus exotic abundance and community composition. In contrast, models of species richness and community compositional change across scales suggest native versus exotic community patterns are largely determined by a mix of scale-dependent concordant (shared positive or negative) and discordant relationships with environmental variables. In addition, detailed analyses of species-area and species-abundance relationships suggest ongoing expansion of exotic species populations, indicating that the assembly of the exotic community is in its early stages. Thus, while competition does not appear to strongly affect native versus exotic abundances and compositions at present, it may intensify in the future. Our results indicate that synoptic patterns in native versus exotic richness that have been previously attributed to a single cause may in fact be due to a complex mix of concordant and discordant responses to environmental factors across scales. They also suggest that conservation efforts aimed at promoting natives and reducing exotics should focus on the factors and scales for which such a response (i.e., promotion of high native and low exotic richness) can be expected.     

黄顶菊在中国的潜在适生区

菊科黄菊属植物黄顶菊近年出现在我国华北地区天津市和河北省的衡水、廊坊等地,其入侵范围有不断扩大的趋势.黄顶菊是一种入侵性极高的一年生杂草,对农牧业生态系统有极大的破坏性.为指导黄顶菊的防除和制定相关的控制政策,本研究根据黄顶菊在其原产地南美洲及扩散入侵地的分布资料,采用CLIMEX生态位模型对其在中国的潜在适生分布区域进行预测.结果表明,黄顶菊在中国的潜在适生区域集中分布于东南部的广东、广西、云南、海南、福建、台湾、江西、湖南、贵州、四川、重庆、湖北、安徽、江苏、上海15个省（市、自治区）,其中高风险区域包括广东、广西、台湾、海南、福建、云南、四川、贵州、重庆和西藏局部地区.     

Testing the Australian Weed Risk Assessment with different estimates for invasiveness

The Weed Risk Assessment (WRA) has become an effective tool in predicting invasiveness of exotic plant species. In studies testing the WRA, exotic plant species are usually divided into major weeds, minor weeds and non-weeds. However, these divisions are qualitative, as the categories are assigned by experts. Many studies searching for plant traits that are indicative of plant invasiveness use quantitative estimates to measure invasiveness. We compared how quantitative and qualitative estimates of invasiveness may relate to WRA scores. As quantitative estimates we used regional frequency (spread), change in regional frequency and local dominance of naturalized exotic plant species in The Netherlands. To obtain a qualitative estimate we determined if the exotic plant species occurred on a black list in neighbouring regions. We related WRA scores of the exotic plant species to these qualitative and quantitative estimates of invasiveness. Our results reveal that the WRA predicted the qualitative (black list) estimate more accurately than the quantitative (dominance and spread) ones. The black list estimate matches with the overall impact of exotic species, which is assumed to incorporate regional spread, local dominance and noxiousness. Therefore, the WRA predicts the noxiousness component, but to a lesser extent the spatial components of impact of exotic species. On the other hand, studies that use regional spread and other quantitative estimates of invasiveness tend not to include the noxiousness component of impact. We propose that our analyses may also help to further solve the recent debate on whether or not performing research on exotic species.     

外来入侵植物银胶菊在广西的分布与危害

银胶菊为一种菊科植物,原产中、南美洲。尽管在广西出现的时间不长,但分布范围较广,由路旁向荒地、耕地发展,引起了很大的危害,包括入侵道路旁,阻碍交通、破坏道路环境;入侵放牧地,减少放牧地产草量;入侵耕地,引起农作物减产;且有毒,能引起人的皮炎、鼻炎及哮喘,危害人类健康。在广西发展成为一种重要的外来入侵植物,已引起科学家的注意。该文介绍了银胶菊的生物学特性和在广西的入侵、扩散等情况,提出了防治措施。     

薇甘菊研究历史与现状

薇甘菊是一种危害极大的杂草,６０年代末就已传入我国的海南,而传入广东大陆沿岸及邻近岛屿如香港、内伶仃岛等并造成较大生态危害是在８０年代末期。９０年代初期,论文从薇甘菊的危害性、生物学、生态学及防治等方面的研究进行综述。     

Plant invaders and their novel natural enemies: who is naïve?

Introduced exotic species encounter a wide range of non‐coevolved enemies and competitors in their new range. Evolutionary novelty is a key aspect of these interactions, but who benefits from novelty: the exotic species or their new antagonists? Paradoxically, the novelty argument has been used to explain both the release from and the suppression by natural enemies. We argue that this paradox can be solved by considering underlying interaction mechanisms. Using plant defenses as a model, we argue that mismatches between plant and enemy interaction traits can enhance plant invasiveness in the case of toxin‐based defenses, whereas invasiveness is counteracted by mismatches in recognition‐based defenses and selective foraging of generalist herbivores on plants with rare toxins. We propose that a mechanistic understanding of ecological mismatches can help to explain and predict when evolutionary novelty will enhance or suppress exotic plant invasiveness. This knowledge may also enhance our understanding of plant abundance following range expansion, or during species replacements along successional stages.