Do alien plants on Mediterranean islands tend to invade different niches from native species?
Do alien plants on Mediterranean islands tend to invade different niches from native species?
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DOI：
10.1007/s10530-007-9163-4
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发表时间：
2008-06-01
影响因子：
2.9
通讯作者：
Hulme, Philip E.
中科院分区：
文献类型：
--
作者：
Lambdon, Philip W.;Lloret, Francisco;Hulme, Philip E.
为了了解入侵，重要的是要知道外来物种如何在不熟悉的生态系统中利用机会。例如，外星人是集中在土著社区开发不足的小生境中，还是广泛分布在整个生态范围内？为了探讨这个问题，我们比较了394个归化外来植物与来自地中海岛屿的本地植物群的代表性样本所占据的生态位。当生态位结构描述的功能组分类，本地和外来物种的分布是非常相似的，虽然“多汁灌木”和“树木专门的动物授粉机制”是在本地物种池的代表性不足。当用Grime的CSR策略描述生态位结构时，外来者和本地人的定位差异更大。压力耐受性是罕见的外国人之间，竞争策略是更普遍的栖息地水平。这一模式类似于以前在欧洲温带地区的发现，尽管在这些地区，它密切反映了本地多样性的模式。在地中海，压力环境更为主导。我们讨论了可能导致这种差异的一些因素，例如，竞争性和原始生态位往往与人类生境有关，其高度可入侵性可能部分是由于引进模式，而不是由于外来者利用这些生态位的效率更高。到目前为止，入侵成功的原因在引进的物种已被证明是难以解开。尽管存在一些差异，但我们的证据表明，外来物种在广泛的生态位中归化。鉴于它们的生态因此差异很大，人们可能会问，为什么这些物种应该被期望分享可预测的特征？
In order to understand invasions, it is important to know how alien species exploit opportunities in unfamiliar ecosystems. For example, are aliens concentrated in niches under-exploited by native communities, or widely distributed across the ecological spectrum? To explore this question, we compared the niches occupied by 394 naturalized alien plants with a representative sample from the native flora of Mediterranean islands. When niche structure was described by a functional group categorization, the distribution of native and alien species was remarkably similar, although "succulent shrubs" and "trees with specialized animal pollination mechanisms" were under-represented in the native species pool. When niche structure was described by Grime's CSR strategy, the positioning of aliens and natives differed more strongly. Stress-tolerance was much rarer amongst the aliens, and a competitive strategy was more prevalent at the habitat level. This pattern is similar to previous findings in temperate Europe, although in those regions it closely reflects patterns of native diversity. Stressed environments are much more dominant in the Mediterranean. We discuss a number of factors which may contribute to this difference, e.g., competitive and ruderal niches are often associated with anthropogenic habitats, and their high invasibility may be due partly to introduction patterns rather than to a greater efficiency of aliens at exploiting them. Thus far, the reasons for invasion success amongst introduced species have proved difficult to unravel. Despite some differences, our evidence suggests that alien species naturalize across a wide range of niches. Given that their ecologies therefore vary greatly, one may ask why such species should be expected to share predictable traits at all?.