Exchanges of enemies between native and non-native plants

本地植物和非本地植物之间的天敌交换

• 批准号: RGPIN-2016-06095
• 负责人: Kotanen, Peter
• 金额: $ 2.04万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=682353
• 关键词: Exchanges; enemies; between; native; non

Escape from native-range natural enemies (herbivores and pathogens) often is argued to increase the invasiveness of non-native plants, as described by the Enemy Release Hypothesis. However, once in a new region, exotic invaders acquire new enemies recruited from invaded-range species. As well, enemies from the invader's original range (including biocontrol agents) may be accidentally or deliberately co-introduced; these species also may attack local natives. As a result, few invaders are free of natural enemies, many of which are shared with co-occurring native plants.***Shared enemies can have significant impacts on invaders, reducing their success through biotic resistance. As well, shared enemies may participate in feedbacks on natives through spillover (spread of introduced enemies from exotic hosts to natives) and spillback (spread of native enemies to exotics followed by spread back onto their original hosts); these feedbacks constitute an important but underexplored component of invaders' ecological impacts. However, not all invasive populations may be equally affected by such interactions. First, the probability of exchange is likely to be lower between more distantly-related natives and exotics. Second, plants that are spatially isolated from sources of enemies may experience reduced exchange. Third, populations of enemies may vary regionally, resulting in geographic trends in exchange. Fourth, even if enemies are shared, tolerance to damage may reduce their effects in favourable habitats. Finally, impacts such as herbivory are likely to be most critical for small populations of invaders; this is the stage at which most unsuccessful invasions fail.***Here, I propose to investigate key factors that affect the exchange of enemies between natives and exotics, and the consequences for the performance of both. We will experimentally test the importance of phylogeny, spatial isolation, and geographic variation for shared enemies, will evaluate the role of tolerance in mitigating these impacts, and will investigate factors affecting the success of small populations. By illuminating the complex web of interactions surrounding invasive plants, this novel research will clarify the importance of shared enemies to the spread of exotics and their impacts on co-occurring natives, and will contribute to my long-term objective of understanding interactions between invasive plants and their natural enemies.**

正如敌人释放假设所描述的那样，经常有人认为逃离天然范围的天然敌人（食草动物和病原体），以增加非本地植物的侵入性。但是，一旦进入新地区，异国情调的入侵者就获得了从入侵范围的物种中招募的新敌人。同样，入侵者原始范围（包括生物防治剂）的敌人可能是意外或故意共同引入的；这些物种也可能攻击当地人。结果，很少有入侵者没有天然敌人，其中许多与共同发生的本地植物共享。同样，共享的敌人可以通过溢出（从异国主义的主人到本地人传播的敌人传播）和溢出（将本地敌人传播到异国情调，然后扩散到他们的原始寄宿者）；这些反馈构成了入侵者生态影响的重要但毫无创伤的组成部分。但是，并非所有侵入性种群都可能同样受这种相互作用的影响。首先，在更遥远的本地人和外来者之间，交换的可能性可能会较低。其次，从敌人来源中空间分离的植物可能会减少交换。第三，敌人的种群可能会在区域变化，从而导致地理趋势交换。第四，即使共享敌人，对损害的容忍度也可能会减少其在有利的栖息地中的影响。最后，诸如食草动物之类的影响可能对少数入侵者人群最为重要。这是最不成功的入侵失败的阶段。我们将在实验上测试系统发育，空间隔离和地理变异对共享敌人的重要性，将评估耐受性在减轻这些影响中的作用，并将研究影响小种群成功的因素。通过阐明围绕侵入性植物的复杂互动网的复杂网络，这项新颖的研究将阐明共同的敌人对外来者的传播及其对共同存在的本地人的影响的重要性，并将有助于我理解入侵植物与自然敌人之间的相互作用的长期目标。** ** ******************************** **