Blumenthal Dana M
Rangeland Resources Research Unit, USDA Agricultural Research Service, 1701 Center Avenue, Fort Collins, CO 80526, USA.
Ecol Lett. 2006 Jul;9(7):887-95. doi: 10.1111/j.1461-0248.2006.00934.x.
Understanding why some exotic species become invasive is essential to controlling their populations. This review discusses the possibility that two mechanisms of invasion, release from natural enemies and increased resource availability, may interact. When plants invade new continents, they leave many herbivores and pathogens behind. Species most regulated by enemies in their native range have the most potential for enemy release, and enemy regulation may be strongest for high-resource species. High resource availability is associated with low defence investment, high nutritional value, high enemy damage and consequently strong enemy regulation. Therefore, invasive plant species adapted to high resource availability may also gain most from enemy release. Strong release of high-resource species would predict that: (i) both enemy release and resources may underlie plant invasion, leading to potential interactions among control measures; (ii) increases in resource availability due to disturbance or eutrophication may increase the advantage of exotic over native species; (iii) exotic species will tend to have high-resource traits relative to coexisting native species; and (iv) although high-resource plants may experience strong enemy release in ecological time, well-defended low-resource plants may have stronger evolutionary responses to the absence of enemies.
了解为何某些外来物种会成为入侵物种对于控制其种群数量至关重要。本综述探讨了两种入侵机制——摆脱天敌和资源可利用性增加——可能相互作用的可能性。当植物入侵新的大陆时，它们会甩掉许多食草动物和病原体。在其原生范围内受天敌调控最严格的物种，天敌释放的潜力最大，而且对于高资源物种来说，天敌调控可能最为强烈。高资源可利用性与低防御投入、高营养价值、高天敌损害以及因此而来的强烈天敌调控相关联。因此，适应高资源可利用性的入侵植物物种可能也会从天敌释放中获益最多。高资源物种的强烈释放预示着：(i) 天敌释放和资源可能都是植物入侵的基础，从而导致控制措施之间存在潜在的相互作用；(ii) 由于干扰或富营养化导致的资源可利用性增加可能会增加外来物种相对于本地物种的优势；(iii) 相对于共存的本地物种，外来物种往往具有高资源特征；以及(iv) 尽管高资源植物在生态时间内可能会经历强烈的天敌释放，但防御良好的低资源植物可能对没有天敌的情况具有更强的进化反应。
