CSIRO Ecosystem Sciences, St. Lucia, Qld 4067, Australia.
Ecol Lett. 2011 Mar;14(3):274-81. doi: 10.1111/j.1461-0248.2010.01584.x. Epub 2011 Feb 1.
Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at 39 sites, within eight countries, revealed that species abundances were similar at native (home) and introduced (away) sites - grass species were generally abundant home and away, while forbs were low in abundance, but more abundant at home. Sites with six or more of these species had similar community abundance hierarchies, suggesting that suites of introduced species are assembling similarly on different continents. Overall, we found that substantial changes to populations are not necessarily a pre-condition for invasion success and that increases in species abundance are unusual. Instead, abundance at home predicts abundance away, a potentially useful additional criterion for biosecurity programmes.
许多全球生态系统都由引入的植物物种主导，导致生物多样性和生态系统功能丧失。一个常见但很少被测试的假设是，这些植物在引入和本地社区中更为丰富，因为种群的生态或进化变化是入侵成功的基础。在这里，来自八个国家的 39 个地点的 26 种草本物种的数据表明，本地（本土）和引入（外来）地点的物种丰度相似——草种在本地和外来地区都很丰富，而杂类草的丰度较低，但在本地更为丰富。有六种或六种以上这些物种的地点具有相似的群落丰度层次结构，这表明引入物种的组合在不同大陆上的组装方式相似。总的来说，我们发现种群的大量变化不一定是入侵成功的先决条件，而且物种丰度的增加并不常见。相反，本地的丰度预测了外地的丰度，这可能是生物安全计划的一个有用的附加标准。
