The Global Distribution and Drivers of Alien Bird Species Richness.
The Global Distribution and Drivers of Alien Bird Species Richness.
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DOI：
10.1371/journal.pbio.2000942
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发表时间：
2017-01
期刊：
影响因子：
9.8
通讯作者：
Blackburn TM
中科院分区：
文献类型：
--
作者：
Dyer EE;Cassey P;Redding DW;Collen B;Franks V;Gaston KJ;Jones KE;Kark S;Orme CD;Blackburn TM
外来物种是人类引起的环境变化的主要组成部分。在不同地区发现的外来物种数量的差异可能取决于人为和环境因素的组合，人为因素影响引入新地点的物种数量，以及何时引进，以及环境因素影响有多少物种能够在那里生存。然而，对外来物种引进和物种丰富的驱动因素的全球时空差异仍然知之甚少。在这里，我们分析了一个广泛的外来鸟类新数据库，以探索是什么决定了整个分类学类别的外来物种丰富度的全球分布。我们证明了外来鸟类的起源和引入的地点以及它们的身份最初主要是由欧洲(主要是英国)殖民主义驱动的。然而，最近的引进是一个更广泛的现象，涉及更多的物种和国家，部分原因是经济活动的增加。我们发现，在全球范围内，外来鸟类的物种丰富度目前在中纬度地区最高，这在很大程度上取决于人类活动的影响，尤其是引入的物种数量(即“殖民压力”)。然而，环境驱动因素也很重要，本地物种和外来物种的丰富度强烈而一致地呈正相关。我们的结果表明，殖民压力是理解外来物种丰富度的关键，表明本地物种丰富度高的地区在全球范围内对外来物种的殖民没有抵抗力，并强调了物种引进可能对全球环境构成的持续威胁。外来物种的引入是人类行动改变环境的主要方式之一。外来物种是许多全球和局部灭绝的罪魁祸首，并正在侵蚀许多自然环境的独特性。因此，有一种基本需要了解哪些地区最终会出现更多外来物种。在这里，我们使用一个关于外来鸟类分布的大型新的全球数据库来显示，首先，引入一个地点的物种数量的模式(殖民压力)是如何随着时间的推移而变化的。我们发现，历史的引入在很大程度上是由欧洲的殖民主义，尤其是英国的殖民主义推动的。然而，鸟类引进的比率正在增加，原产地和物种引进地点的转变可能是由笼鸟贸易推动的。然后，我们将鸟类物种在哪里引入的信息与外来鸟类物种丰富度的全球地图结合起来，以确定丰富度的主要驱动因素。我们发现，殖民压力是外来鸟类物种丰富度的最强预测因子，但还有其他人为和环境驱动因素。最值得注意的是，一旦考虑到殖民压力，在本地鸟类物种丰富度较高的地区，外来鸟类物种丰富度就会更高。
Alien species are a major component of human-induced environmental change. Variation in the numbers of alien species found in different areas is likely to depend on a combination of anthropogenic and environmental factors, with anthropogenic factors affecting the number of species introduced to new locations, and when, and environmental factors influencing how many species are able to persist there. However, global spatial and temporal variation in the drivers of alien introduction and species richness remain poorly understood. Here, we analyse an extensive new database of alien birds to explore what determines the global distribution of alien species richness for an entire taxonomic class. We demonstrate that the locations of origin and introduction of alien birds, and their identities, were initially driven largely by European (mainly British) colonialism. However, recent introductions are a wider phenomenon, involving more species and countries, and driven in part by increasing economic activity. We find that, globally, alien bird species richness is currently highest at midlatitudes and is strongly determined by anthropogenic effects, most notably the number of species introduced (i.e., “colonisation pressure”). Nevertheless, environmental drivers are also important, with native and alien species richness being strongly and consistently positively associated. Our results demonstrate that colonisation pressure is key to understanding alien species richness, show that areas of high native species richness are not resistant to colonisation by alien species at the global scale, and emphasise the likely ongoing threats to global environments from introductions of species. The introduction of alien species is one of the primary ways in which human actions are changing the environment. Alien species have been responsible for numerous global and local extinctions and are eroding the uniqueness of many natural environments. There is thus a basic need to understand which areas end up with more alien species. Here, we use a major new global database on the distribution of alien birds to show, first, how patterns in the number of species introduced to a location (colonisation pressure) have changed over time. We show that historical introductions were driven largely by European, and especially British, colonialism. However, the rate of bird introductions is increasing, with shifts in the locations of origin and introduction of species probably driven by the cage bird trade. We then combine information on where bird species have been introduced with a global map of alien bird species richness to identify the main drivers of richness. We show that colonisation pressure is the strongest predictor of alien bird species richness, but that there are other anthropogenic and environmental drivers. Most notably, once colonisation pressure has been accounted for, alien bird species richness is higher in areas where native bird species richness is higher.