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。     

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。     

澳大利亚外来入侵物种管理策略及对我国的借鉴意义

澳大利亚是一个岛状大陆,海洋运输业十分发达,通过贸易、旅游、运输等途径有意或无意引进有害外来物种的风险较大。澳大利亚政府高度重视外来入侵物种的管理工作,制定了《澳大利亚国家生物多样性保护策略》,针对外来杂草和通过压舱水载入的海洋外来入侵物种的管理制定了《国家杂草策略》、《杂草风险评价系统》和《压舱水指南》等法规和技术性文件,加强了对外来入侵物种的管理。本文简要介绍了澳大利亚外来入侵物种管理的有关策略和指南,并提出了我国在外来入侵物种管理方面的对策建议：（1）尽快建立相应的法规体系,实现外来入侵物种的依法管理;（2）加强机构建设,形成多部门的协调管理机制;（3）加强外来入侵物种管理制度的建设;（4）采取适当的引进预防、消除、控制和恢复措施;（5）开展科学研究,为外来入侵物种的管理提供科学依据;（6）制定教育和培训计划,提高公众意识。     

影响河北省外来物种入侵的社会经济因素分析

【目的】探讨影响河北省外来物种入侵的社会经济因素,以期能够为河北省外来物种的防控提供可行性建议对策。【方法】通过查阅期刊、专著和数据库等分析了河北省外来入侵物种情况,对2003、2007、2011、2015、2019年5个时间节点的进口贸易、旅游人数、境内公路公里数3个社会经济变量与外来入侵物种量进行相关性分析,明确影响河北省外来入侵生物的社会经济因素,进而通过建立时间序列模型预测出未来几年进口贸易额的变化情况,利用曲线估计预测2023年的外来入侵物种数量。【结果】河北省外来入侵物种数呈现逐年增长的趋势,且在各年的外来入侵物种中均有超过85%是与人类活动有关;进口贸易总额、入境旅游总人数和境内公路公里数与外来入侵物种数之间都表现出显著的正相关关系;预测显示,到2023年河北省的外来入侵物种数将达到367种。【结论】社会经济的发展将会带来更多的外来入侵物种,基于河北省外来入侵生物的入侵途径提出了防控外来物种入侵的对策。     

微生物入侵影响因素研究进展

探明生物入侵的影响因素能够有效防治生物入侵,减少其对生态系统的破坏,但现有的入侵研究主要集中于动植物入侵,对微生物入侵关注较少。本文综述了外来微生物自身属性、入侵地生物和非生物状况以及外来种和土著种之间差异等对微生物入侵的影响,比较了微生物入侵与动植物入侵、微生物定殖之间的差别,提出了今后需要进一步加强的研究内容。外来微生物入侵受其自身种系、形态、大小等特性,入侵地生物多样性、天敌、有效资源等生物或非生物因子,以及外来-本地种谱系距离、生态位差异、相对适应性差异等三方面因素共同影响,但不同因素之间的关联度、交互性及相对贡献仍不清楚。外来微生物入侵过程与动植物入侵过程、微生物定殖过程有诸多类似之处,但同时也存在不少差异。今后,需加强研究外来微生物独特性状(如:持留状态和群体感应等)对其入侵影响,关注微生物进入新环境的存活数量、扩散范围和影响程度,加强利用定殖研究中常用的微生物作为入侵物种验证经典入侵理论,以及注重观察全球变化下外来微生物的入侵趋势和区分微生物在不同入侵阶段的主要影响因素。     

安徽省外来入侵植物的分布格局及其等级划分

区域性外来入侵植物的研究及其入侵等级划分在地方入侵植物管理与防治对策的制定上具有重要的指导意义。本文基于文献报道、标本记录和必要的分类学考证,特别是通过2013-2015年对安徽省外来入侵植物的全面调查,统计分析了安徽省外来入侵植物的物种组成、生活型、原产地、区系组成和水平分布格局,并对其入侵危害进行等级划分。结果显示,安徽省有外来入侵植物37科86属132种,总体上呈现种类丰富、原产于美洲的种类多、泛热带起源的种类多、危害严重的种类多、区域分化明显、入侵途径集中等特征。提出在外来入侵植物的防控中应重点警惕起源于美洲的、泛热带分布属的植物和关注人类活动频繁的热点区域。还对中国外来入侵植物研究中存在的问题进行了探讨,澄清了几个长期以来被忽视的关于外来入侵物种认知的问题。     

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。     

云南的外来入侵植物

综述云南外来入侵植物的现状、分布、入侵的主要途径和危害等。列出云南外来入侵植物75种的详细资料,详细论述其中危害较严重的紫茎泽兰、飞机草、凤眼莲、空心莲子草、马缨丹和肿柄菊等,并讨论应采取的防治对策。提出云南是我国生物多样性最丰富的地区,但也是外来入侵植物危害最严重的地区;虽然很多外来入侵植物都能在云南蔓延,但真正引起严重危害的却不多;恢复本地植被,减少对生态系统的干扰,建立外来入侵物种监测机制和风险评价体系将是防范外来入侵植物的有效途径。     

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。     

京津冀外来入侵植物的种类调查与分析

【目的】近年来,外来入侵植物对京津冀地区的生态安全和经济贸易发展构成了严重威胁。了解京津冀地区入侵植物种类组成,分析其分布特点,能够为京津冀地区外来入侵植物扩散的防控、生物多样性保护与生态安全提供理论依据。【方法】对京津冀外来入侵植物的种类、原产地、生活型、危害程度、引入途径等进行调查和分析。【结果】京津冀目前有99种外来入侵植物,其中恶性杂草11种。菊科和禾本科为优势科,所含种数分别为24和12种。京津冀外来入侵植物以一、二年草本植物为主;美洲是京津冀入侵植物的最大起源地,其中,北美地区23种,美洲热带和中、南美洲共32种;人为有意引进共56种,占外来入侵植物总种数的56.57%。【结论】当前京津冀地区外来植物入侵状况比较严重,且该地区入侵植物的入侵与其社会经济学因子和生物地理学因子密切有关,有意引入是京津冀地区外来植物入侵的主要途径。     

Exploration for native parasitoids of Asian longhorned beetle in China as prospective biological control agents

1. Native to China and the Korean Peninsula, the Asian longhorned beetle (ALB) Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) is a high-risk invasive pest of hardwood trees.
2. To explore the potential of biological control of ALB in the United States, we conducted surveys of ALB parasitoids using sentinel logs in five geographical regions (Beijing, Gansu, Guizhou, Shanghai, and Yunnan) in China from 2019 to 2022.
3. Seven hymenopteran larval parasitoid species, Bracon planitibiae Yang, Eurytoma chinensis Yang, Heydenia sp., Oxysychus glabripennis Yang, Sclerodermus guani Xiao et Wu, Spathius anoplophorae Yang, and Zolotarewskya anoplophorae Yang, were collected in Beijing. Four, three and two of these species were also found in Shanghai, Guizhou, and Yunnan, respectively. No parasitoid was found in Gansu.
4. Mean parasitism rates by all parasitoid species were 3.6%–15.8% in Beijing, 1.4%–16.4% in Guizhou, 1.6%–7.1% in Shanghai, and 5.8% in Yunnan.
5. Spathius anoplophorae and O. glabripennis were the two most dominant parasitoids collected consistently in the four different regions and may be considered as prospective agents for biological control introduction against ALB in the United States.
6. We discuss some underlying ecological mechanisms that might contribute to the rarity of egg parasitoids and future opportunities and challenges for biological control of ALB.

     

The influence of forest stand and site characteristics on the composition of exotic dominated ambrosia beetle communities (Coleoptera: Curculionidae: Scolytinae)

Economic and biological consequences are associated with exotic ambrosia beetles and their fungal associates. Despite this, knowledge of ambrosia beetles and their ecological interactions remain poorly understood, especially in the oak-hickory forest region. We examined how forest stand and site characteristics influenced ambrosia beetle habitat use as evaluated by species richness and abundance of ambrosia beetles, both the native component and individual exotic species. We documented the species composition of the ambrosia beetle community, flight activity, and habitat use over a 2-yr period by placing flight traps in regenerating clearcuts and older oak-hickory forest stands differing in topographic aspect. The ambrosia beetle community consisted of 20 species with exotic ambrosia beetle species dominating the community. Similar percentages of exotic ambrosia beetles occurred among the four forest habitats despite differences in stand age and aspect. Stand characteristics, such as stand age and forest structure, influenced ambrosia beetle richness and the abundances of a few exotic ambrosia beetle species and the native ambrosia beetle component. Topographic aspect had little influence on ambrosia beetle abundance or species richness. Older forests typically have more host material than younger forests and our results may be related to the amount of dead wood present. Different forms of forest management may not alter the percent contribution of exotic ambrosia beetles to the ambrosia beetle community.     

白蜡窄吉丁虫在中国的研究现状与分布调查

2002年在美国密执安州发现了一重大外来入侵害虫,白蜡窄吉丁Agrilus planipennis Fairmaire, 由于该虫新近在美国发现,危害白蜡树,故英文名称为Emerald Ash Borer (EAB)。初步分析显示,该虫至少在5年前就已传入美国,只是现在刚爆发被发现。目前该虫在美国密执安州和加拿大安大略省可致死各种大小的白蜡树。该虫在我国曾被定名为花曲柳窄吉丁Agrilus marcopoli Obenberger,为鞘翅目吉丁科。据资料报道分布于黑龙江、吉林、辽宁、山东、内蒙古和台湾等地;在国外分布于朝鲜,日本,蒙古,俄罗斯远东地区。危害木樨科属树木。两年一代或一年一代,因地而已。在东北三省主要危害水曲柳和花曲柳等树木,但不是主要害虫。天津市1993年在引种白蜡树上发现了白蜡窄吉丁,1998年严重爆发造成大面积白蜡树死亡。在亚洲的其他分布区,该虫还危害另外一些阔叶树,如多种蜡树、榆树等。鉴于该虫的广泛分布和寄主树种多及毁灭性危害的特点,美国一些专家认为其潜在危害不亚于1996年在美国发现的光肩星天牛。因此,美国已全面开展对该虫的研究,包括资料收集,风险性评估,研究各种控制措施等。 本文是中美对此虫合作研究的一部分,旨在对该虫在我国的分布、 危害、 研究基础作一调查与回顾, 为下一步深入研究提供信息与参考资料。白蜡窄吉丁入侵北美再一次显示随着贸易的全球化发展, 外来入侵种问题也越来越严重。国际合作共同开展研究是控制入侵种的重要举措之一。     

Large carbon release legacy from bark beetle outbreaks across Western United States

Warmer conditions over the past two decades have contributed to rapid expansion of bark beetle outbreaks killing millions of trees over a large fraction of western United States (US) forests. These outbreaks reduce plant productivity by killing trees and transfer carbon from live to dead pools where carbon is slowly emitted to the atmosphere via heterotrophic respiration which subsequently feeds back to climate change. Recent studies have begun to examine the local impacts of bark beetle outbreaks in individual stands, but the full regional carbon consequences remain undocumented for the western US. In this study, we quantify the regional carbon impacts of the bark beetle outbreaks taking place in western US forests. The work relies on a combination of postdisturbance forest regrowth trajectories derived from forest inventory data and a process‐based carbon cycle model tracking decomposition, as well as aerial detection survey (ADS) data documenting the regional extent and severity of recent outbreaks. We find that biomass killed by bark beetle attacks across beetle‐affected areas in western US forests from 2000 to 2009 ranges from 5 to 15 Tg C yr^?1 and caused a reduction of net ecosystem productivity (NEP) of about 6.1–9.3 Tg C y^?1 by 2009. Uncertainties result largely from a lack of detailed surveys of the extent and severity of outbreaks, calling out a need for improved characterization across western US forests. The carbon flux legacy of 2000–2009 outbreaks will continue decades into the future (e.g., 2040–2060) as committed emissions from heterotrophic respiration of beetle‐killed biomass are balanced by forest regrowth and accumulation.     

树木-蛀干昆虫-天敌昆虫间的三级营养关系

以小蠹虫和天牛为主的蛀干昆虫是为害林木的重要经济害虫,常对森林生态系统造成重大灾害.本文以林业主要害虫——小蠹虫和天牛为例,综述了树木、蛀干害虫和其天敌组成的三级营养系统间相互关系的研究概况,从不同侧面介绍了近十年来在引诱天敌的信息化学物质的释放部位、活性化合物的鉴定、挥发性化合物的释放动态等方面的研究成果,同时对于天敌对信息化学物质的选择性、天敌视觉在寻找寄主或猎物方面的作用以及是否涉及到影响天敌行为的三级营养以外的其它生物活性物质等的研究进展作了简略介绍.     

Interactions among fire, insects and pathogens in coniferous forests of the interior western United States and Canada

1 Natural and recurring disturbances caused by fire, native forest insects and pathogens have interacted for millennia to create and maintain forests dominated by seral or pioneering species of conifers in the interior regions of the western United States and Canada. 2 Changes in fire suppression and other factors in the last century have altered the species composition and increased the density of trees in many western forests, leading to concomitant changes in how these three disturbance agents interact. 3 Two‐ and three‐way interactions are reviewed that involve fire, insects and pathogens in these forests, including fire‐induced pathogen infection and insect attack, the effects of tree mortality from insects and diseases on fuel accumulation, and efforts to model these interactions. 4 The emerging concern is highlighted regarding how the amount and distribution of bark beetle‐caused tree mortality will be affected by large‐scale restoration of these fire‐adapted forest ecosystems via prescribed fire. 5 The effects of fire on soil insects and pathogens, and on biodiversity of ground‐dwelling arthropods, are examined. 6 The effects of fire suppression on forest susceptibility to insects and pathogens, are discussed, as is the use of prescribed fire to control forest pests.     

Roles of bacteria in the bark beetle holobiont – how do they shape this forest pest?

Bark beetles are well‐known forest pests, some species inducing massive attacks on trees, resulting in the devastation of entire woodlands. Bark beetles are associated with microorganisms, forming an entity known as ‘holobiont’. Beetles and fungi are the best‐studied members of this multipartite symbiosis. However, recent studies have shown that bacteria may play important roles in the bark beetle holobiont, such as providing certain nutrients, promoting the growth of beneficial fungi, detoxifying the environment by lowering the levels of phenolic compounds synthesised by the host tree or by inhibiting the growth of antagonistic fungi whereas some bacterial symbionts have the potential to kill beetles under certain conditions. Therefore, bacteria probably greatly affect the life cycle of bark beetles; hence, more research is needed to clarify the extent to which a bacterial associate is implicated in a bacterial bark beetle symbiosis and how much it determines host's performance. This review summarises all of the known activities of bacteria present in the bark beetle holobiont, indicates some important gaps in the knowledge of this symbiosis and provides some guidance for overcoming the difficulties in investigating this relationship in future studies.     

Deciphering the worldwide invasion of the Asian long‐horned beetle: A recurrent invasion process from the native area together with a bridgehead effect

Retracing introduction routes is crucial for understanding the evolutionary processes involved in an invasion, as well as for highlighting the invasion history of a species at the global scale. The Asian long‐horned beetle (ALB) Anoplophora glabripennis is a xylophagous pest native to Asia and invasive in North America and Europe. It is responsible for severe losses of urban trees, in both its native and invaded ranges. Based on historical and genetic data, several hypotheses have been formulated concerning its invasion history, including the possibility of multiple introductions from the native zone and secondary dispersal within the invaded areas, but none have been formally tested. In this study, we characterized the genetic structure of ALB in both its native and invaded ranges using microsatellites. In order to test different invasion scenarios, we used an approximate Bayesian “random forest” algorithm together with traditional population genetics approaches. The strong population differentiation observed in the native area was not geographically structured, suggesting complex migration events that were probably human‐mediated. Both native and invasive populations had low genetic diversity, but this characteristic did not prevent the success of the ALB invasions. Our results highlight the complexity of invasion pathways for insect pests. Specifically, our findings indicate that invasive species might be repeatedly introduced from their native range, and they emphasize the importance of multiple, human‐mediated introductions in successful invasions. Finally, our results demonstrate that invasive species can spread across continents following a bridgehead path, in which an invasive population may have acted as a source for another invasion.     

外来入侵林业害虫强大小蠹的侵袭以及相关信息化学物质

强大小蠹是入侵我国并造成很大危害的鞘翅目棘胫小蠹科大小蠹属树皮低干森林害虫。它能侵害多种针叶树和松树 ,能被寄主挥发物和其它小蠹虫的外激素所引诱。该文综述了强大小蠹的侵袭习性以及寄主挥发物、其它小蠹虫的外激素对强大小蠹的引诱和驱避作用。     

Cross-Attraction between an Exotic and a Native Pine Bark Beetle: A Novel Invasion Mechanism?

Background

Aside from the ecological impacts, invasive species fascinate ecologists because of the unique opportunities that invasives offer in the study of community ecology. Some hypotheses have been proposed to illustrate the mechanisms that allow exotics to become invasive. However, positive interactions between exotic and native insects are rarely utilized to explain invasiveness of pests.

Methodology/Principal Findings

Here, we present information on a recently formed association between a native and an exotic bark beetle on their shared host, Pinus tabuliformis, in China. In field examinations, we found that 35–40% of P. tabuliformis attacked by an exotic bark beetle, Dendroctonus valens, were also attacked by a native pine bark beetle, Hylastes parallelus. In the laboratory, we found that the antennal and walking responses of H. parallelus to host- and beetle-produced compounds were similar to those of the exotic D. valens in China. In addition, D. valens was attracted to volatiles produced by the native H. parallelus.

Conclusions/Significance

We report, for the first time, facilitation between an exotic and a native bark beetle seems to involve overlap in the use of host attractants and pheromones, which is cross-attraction. The concept of this interspecific facilitation could be explored as a novel invasive mechanism which helps explain invasiveness of not only exotic bark beetles but also other introduced pests in principle. The results reported here also have particularly important implications for risk assessments and management strategies for invasive species.