Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark.
Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark
AoB Plants. 2015 Apr 8;7:plv025. doi: 10.1093/aobpla/plv025.
Introduction of exotic organisms that subsequently become invasive is considered a serious threat to global biodiversity, and both scientists and nature-conservationists attempt to find explanations and means to meet this challenge. This requires a thorough analysis of the invasion phenomenon in an evolutionary and ecological context; in the case of invasive plants, we must have a major focus on above-belowground interactions. Thus, we discuss different theories that have been proposed to explain the course of invasions through interactions between plants and soil organisms. Further, a thorough analysis of invasion must include a temporal context. Invasions will typically include an initial acute phase, where the invader expands its territory and a later chronic phase where equilibrium is re-established. Many studies fail to make this distinction, which is unfortunate as it makes it impossible to thoroughly understand the invasion of focus. Thus, we claim that invasions fall into two broad categories. Some invasions irreversibly change pools and pathways of matter and energy in the invaded system; even if the abundance of the invader is reduced or it is completely removed, the system will not return to its former state. We use earthworm invasion in North America as a particular conspicuous example of invasive species that irreversibly change ecosystems. However, invasions may also be reversible, where the exotic organism dominates the system for a period, but in the longer term it either disappears, declines or its negative impact decreases. If the fundamental ecosystem structure and flows of energy and matter have not been changed, the system will return to a state not principally different from the original.
引入随后成为入侵物种的外来生物被认为是对全球生物多样性的严重威胁，科学家和自然保护主义者都试图寻找解释和方法来应对这一挑战。这需要在进化和生态背景下对入侵现象进行彻底分析；就入侵植物而言，我们必须将重点主要放在地上和地下相互作用上。因此，我们讨论了不同的理论，这些理论试图解释植物与土壤生物之间的相互作用导致入侵的过程。此外，对入侵的彻底分析必须包括时间背景。入侵通常包括一个初始的急性阶段，在此阶段，入侵者会扩大其领地，然后进入一个后期的慢性阶段，在这个阶段会重新建立平衡。许多研究未能做出这种区分，这很不幸，因为这使得人们不可能彻底理解所关注的入侵。因此，我们声称入侵可以分为两大类。有些入侵会不可逆转地改变被入侵系统中物质和能量的库和途径；即使入侵生物的丰度减少或被完全清除，系统也不会恢复到原来的状态。我们以北美蚯蚓入侵为例，特别明显的例子是入侵物种会不可逆转地改变生态系统。然而，入侵也可能是可逆的，外来生物在一段时间内主导系统，但从长期来看，它要么消失、衰退，要么其负面影响减小。如果基本的生态系统结构和能量及物质的流动没有改变，系统将恢复到与原始状态基本不同的状态。
