再谈生物入侵

生物入侵就是某种物种从它的原产地,通过非自然途径迁移到新的生态环境的过程。这些被称为生物入侵者的物种或外来种（在新区定殖,建立自然种群的生物）,其中一部分是有益的,如玉米、红薯、马铃薯等,已为世界公认,但另一部分有害：由于其有广泛的适应性,极强的繁殖能力,不仅会对“入侵领地”的生物多样性形成威胁,破坏生态平衡,还会给人类社会造成难以估量的损失。１生物入侵对社会经济的危害 如果一个物种在新的生存环境中不受食物竞争以及天敌伤害等因素制约,那么它很可能无节制地繁衍,种群迅速扩大,发展成为当地新的优势种…     

生物入侵及其影响

生物入侵是物种进入其在进化史上未分布过的地域而且能在该地繁衍.生物入侵是一种十分普遍的现象.生物入侵的影响大,危害严重.生物入侵的影响有:①对生物个体的影响;②对遗传的影响; ③对种群动态的影响;④对群落的影响;⑤对生态系统进程的影响.不同的生物入侵造成的影响不一样,应该有区别地分析.     

生物入侵对鸟类的生态影响

生物入侵是全球生物多样性面临的最主要威胁之一, 入侵种在改变入侵地环境的同时也使当地的生物受到极大影响。鸟类在生态系统中处于较高的营养级, 生态系统中任何一个环节的变化都可能对鸟类造成一定的影响。本文回顾了哺乳动物、鸟类、无脊椎动物和植物等不同生物类群的入侵对本地鸟类生态影响方面的研究进展。外来生物对鸟类的影响主要表现在以下几方面: (1)外来哺乳动物对成鸟、幼鸟或鸟卵的捕食作用; (2)外来鸟类与本地鸟类竞争栖息地和食物资源, 与当地的近缘种杂交而造成基因流失; (3)外来无脊椎动物改变本地鸟类的栖息环境和食物状况, 甚至直接捕食本地鸟类; (4)外来植物入侵改变入侵地的植物群落组成和结构, 造成本地鸟类的栖息地丧失或破碎化, 并通过改变入侵地生态系统的食物链结构而对高营养级的鸟类产生影响。最后, 作者还提出了该领域有待解决的问题和今后可能的研究方向。     

狙击生物入侵的对策探讨

我国加入 WTO后 ,随着世界经济贸易自由化进程和改革开放步伐的加快 ,国际生物水平的科技成果或产品将渗透进入我国生物界中 ,外来生物在丰富我们生物物种的同时 ,也会带来负面影响。近期生物界出现一个新的名词——生物入侵 ,是指生物由原生地经自然或人为的途径侵入到另一个新环境 ,对入侵地的生物多样性 ,农林牧渔业生产以及人类健康造成经济损失或生态灾难。通俗地说 ,就是外来物种“入侵并打败”当地物种 ,“反客为主”,导致当地生态失衡 ,进而引发一系列的问题。近年来 ,随着全球经济一体化步伐的加快 ,国内外贸易往来越来越频繁 ,…     

生物入侵的影响是否准确可知?

生物入侵常常带来一系列负面影响, 如物种快速丧失、巨大经济损失、生态公益急剧降低、不可逆环境破坏等。正是这些负面影响引起科技界、政府和公众对生物入侵的极大关注。因此, 准确量化生物入侵的影响非常重要。然而, 广泛使用的生物入侵影响评估方法存在两个严重缺陷: 一是缺乏真实对照, 二是包含非入侵效应。这两个缺陷使得人们对生物入侵影响的了解相对粗略。为此, 作者提出两点建议: 一是在实验条件下设置真实对照, 二是考虑同步对照。评估方法的完善将有助于人们更加准确地理解生物入侵的影响。     

生物入侵的进化生物学

生物入侵(Biological invasion) 是指一种生物在人类活动的影响下,从原产地进入到一个新的栖息地,并通过定居(Colonizing) 、建群( Establishing) 和扩散(Diffusing) 而逐渐占领该栖息地,从而对当地土著生物和生态系统造成负面影响的一种生态现象。       

浅谈生物入侵的条件及其两面性

外来入侵生物日益影响着生态系统和人类的生存环境,引起人们的广泛关注。生物入侵的条件是适应性强、繁殖力强、缺少天敌且入侵地的生态系统比较脆弱。生物入侵虽然在一定程度上给人类带来许多不利因素,增加了不必要的劳力和财力,但在获得当地生态系统的"包容"后,又能产生一定的生物学和经济学价值。在避害除弊的同时,合理管理和利用入侵外来生物,可减少其危害程度,增加可用性。基于现状/危害评估的应对机制和基于国情/地区实情的应对机制,可以采取生物入侵综合控制与管理的措施。     

生物入侵的后果凸显种间互惠对植物群落的重要性

“动物＿植物＿种子传播”系统中种子传播者和植物的互惠关系对维持物种延续、群落结构与更新及多样性等有着重要的作用。世界范围内种子传播者的减少甚至灭绝对植物的影响日益受到关注。“关键互惠假说 (ｋｅｙｓｔｏｎｅｍｕｔｕａｌｉｓｔｈｙｐｏｔｈｅｓｉｓ)”认为 ,人为因素使群落中某一物种丢失 ,会引发相关物种连锁灭绝的灾难。在南非高山硬叶灌木群落 (ｆｙｎｂｏｓ)中 ,30 %植物种子依靠蚂蚁传播。按种子大小及种子上的油状物 (ｅｌａｉｏｓｏｍｅ)将群落中蚁传的优势种山龙眼科 (Ｐｒｏｔｅａｃｅａｅ) 2 3种植物分为大种子和小…     

生物入侵对黄河流域生态系统的影响及对策

黄河流域健康的生态系统是沿黄地区生态保护和高质量发展的核心。然而, 随着经济高速发展和人类活动增加, 大量的外来生物传入并占据黄河流域生态位。这些外来生物在黄河流域的大肆扩繁给黄河流域本土生物和生态系统带来了严重威胁, 甚至严重影响人类健康。因此, 研究黄河流域的外来生物入侵问题, 并提出保护对策, 对于黄河流域生态保护和高质量发展具有重大意义。本文主要从黄河流经九省区(包含黄河流域)外来入侵生物的传入特征、传播途径、种群动态、成灾机制以及入侵生物对黄河流域重要生物资源和生态系统的影响等方面进行综述, 并提出了防控黄河流域生物入侵、保护黄河流域健康的生态系统的措施和对策。     

全球气候变化与生物入侵

近年来,人们能越来越明显地感受到全球气候的变化,例如气温升高、降水量增加和极端气候事件增多等。而生物入侵由于对生物多样性和经济造成了巨大影响,也逐渐受到研究人员和各国政府的重视。全球气候变化因素众多,不可避免地影响到了生物入侵进程和成功率,而大规模生物入侵对森林和海滨生态系统的破坏反过来也将对全球气候造成影响。本文探讨了全球气候变化与生物入侵的关系,以及造成这些关系的相关机理。     

A proposed unified framework for biological invasions

There has been a dramatic growth in research on biological invasions over the past 20 years, but a mature understanding of the field has been hampered because invasion biologists concerned with different taxa and different environments have largely adopted different model frameworks for the invasion process, resulting in a confusing range of concepts, terms and definitions. In this review, we propose a unified framework for biological invasions that reconciles and integrates the key features of the most commonly used invasion frameworks into a single conceptual model that can be applied to all human-mediated invasions. The unified framework combines previous stage-based and barrier models, and provides a terminology and categorisation for populations at different points in the invasion process.     

Allee effects in biological invasions

Understanding the dynamics of small populations is obviously important for declining or rare species but is also particularly important for invading species. The Allee effect, where fitness is reduced when conspecific density is low, can dramatically affect the dynamics of biological invasions. Here, we summarize the literature of Allee effects in biological invasions, revealing an extensive theory of the consequences of the Allee effect in invading species and some empirical support for the theory. Allee effects cause longer lag times, slower spread and decreased establishment likelihood of invasive species. Expected spatial ranges, distributions and patterns of species may be altered when an Allee effect is present. We examine how the theory can and has been used to detect Allee effects in invasive species and we discuss how the presence of an Allee effect and its successful or unsuccessful detection may affect management of invasives. The Allee effect has been shown to change optimal control decisions, costs of control and the estimation of the risk posed by potentially invasive species. Numerous ways in which the Allee effect can influence the efficacy of biological control are discussed.     

Global change and biological invasions

Invasion by exotic species is one of the serious socio-economic, environmental and ecological problems currently faced by mankind. Biological invasions have changed the species composition, structure and function of ecosystems, and are seriously threatening global biodiversity, economy and human health (Iqbal et al. 2021; Wang et al. 2020; Yang et al. 2021; Zhao et al. 2020; Zheng et al. 2015). Biological invasions have resulted in an economic loss of at least US$ 1.288 trillion over the past few decades worldwide (Diagne et al. 2021). As a consequence of these far-reaching impacts, biological invasions have become a hot research topic in modern ecology, and attract major attention from international organizations, governments and scientists all over the world. There is a complex interaction between biological invasions and global environmental change. Biological invasions are not only passengers of global change, but can also be major drivers of global change (MacDougall and Turkington 2005). Other components of global change, such as atmospheric CO₂ enrichment, global warming, nitrogen deposition, changes in precipitation regimes, habitat fragmentation and land-use change, affect species distributions and resource dynamics of ecosystems, and consequently drive invasion success of many exotic species. On the other hand, invasion by exotic species can also alter basic ecosystem properties, which in turn affect many components of global change. Research on the patterns, processes and mechanisms of biological invasion can shed light on the drivers and consequences of biological invasions in the light of global change, and serve as a scientific basis for forward-thinking management plans. The overarching challenge is to understand the basic ecological interactions of, e.g., invasive and native species, plants and soil, and plants and animals.     

The fungal dimension of biological invasions

Fungi represent an essential component of biodiversity, not only because of the large number of species, but also for their ecological, evolutionary and socio-economic significance. Yet, until recently, fungi received scant consideration in ecology, especially invasion ecology. Their under-representation is largely the result of a lack of scientific knowledge of fungal biodiversity and ecology. With the exception of pathogenic fungi, which cause emergent infectious diseases, the impact of fungal invasions is often difficult to quantify owing to limited baseline data on fungal communities. Here, we aim to raise awareness among mycologists and ecologists of the fungal dimension of invasions and of the need to intensify research in fungal ecology to address issues of future introductions.     

Evolutionary indirect effects of biological invasions

Just as ecological indirect effects can have a wide range of consequences for community structure and ecosystem function, theory suggests that evolutionary indirect effects can also influence community dynamics and the outcome of species interactions. There is little empirical evidence documenting such effects, however. Here, I use a multi-generation selection experiment in the field to investigate: (1) how the exotic plant Medicago polymorpha and the exotic insect herbivore Hypera brunneipennis affect the evolution of anti-herbivore resistance traits in the native plant Lotus wrangelianus and (2) how observed Lotus evolutionary responses to Hypera alter interactions between Lotus and other members of the herbivore community. In one of two study populations, I document rapid evolutionary changes in Lotus resistance to Hypera in response to insecticide treatments that experimentally reduced Hypera abundance, and in response to Medicago-removal treatments that also reduced Hypera abundance. These evolutionary changes in response to Hypera result in reduced attack by aphids. Thus, an evolutionary change caused by one herbivore species alters interactions with other herbivore taxa, an example of an eco-evolutionary feedback. Given that many traits mediate interactions with multiple species, the effects of evolutionary changes in response to one key biotic selective agent may often cascade through interaction webs to influence additional community members.