Miller Joseph T, Hui Cang, Thornhill Andrew, Gallien Laure, Le Roux Johannes J, Richardson David M
National Research Collections Australia, CSIRO National Facilities and Collections, GPO Box 1600, Canberra, ACT 2601, Australia.
Office of International Science and Engineering, National Science Foundation, Arlington, Virginia 22230, USA.
AoB Plants. 2016 Dec 30;9(1). doi: 10.1093/aobpla/plw080.
For a plant species to become invasive it has to progress along the introduction-naturalization-invasion (INI) continuum which reflects the joint direction of niche breadth. Identification of traits that correlate with and drive species invasiveness along the continuum is a major focus of invasion biology. If invasiveness is underlain by heritable traits, and if such traits are phylogenetically conserved, then we would expect non-native species with different introduction status (i.e. position along the INI continuum) to show phylogenetic signal. This study uses two clades that contain a large number of invasive tree species from the genera Acacia and Eucalyptus to test whether geographic distribution and a novel phylogenetic conservation method can predict which species have been introduced, became naturalized, and invasive. Our results suggest that no underlying phylogenetic signal underlie the introduction status for both groups of trees, except for introduced acacias. The more invasive acacia clade contains invasive species that have smoother geographic distributions and are more marginal in the phylogenetic network. The less invasive eucalyptus group contains invasive species that are more clustered geographically, more centrally located in the phylogenetic network and have phylogenetic distances between invasive and non-invasive species that are trending toward the mean pairwise distance. This suggests that highly invasive groups may be identified because they have invasive species with smoother and faster expanding native distributions and are located more to the edges of phylogenetic networks than less invasive groups.
对于一种植物物种要成为入侵物种，它必须沿着引入-归化-入侵（INI）连续统发展，该连续统反映了生态位宽度的联合方向。识别与物种在连续统上的入侵性相关并驱动其入侵性的特征是入侵生物学的一个主要重点。如果入侵性由可遗传的特征支撑，并且如果这些特征在系统发育上是保守的，那么我们会预期具有不同引入状态（即沿着INI连续统的位置）的非本地物种会表现出系统发育信号。本研究使用了两个包含大量来自金合欢属和桉属的入侵树种的分支，以测试地理分布和一种新的系统发育保守方法是否能够预测哪些物种已被引入、已归化以及具有入侵性。我们的结果表明，除了引入的金合欢外，两组树木的引入状态均没有潜在的系统发育信号。入侵性更强的金合欢分支包含地理分布更平滑且在系统发育网络中更处于边缘位置的入侵物种。入侵性较弱的桉属组包含地理上更聚集、在系统发育网络中位置更居中且入侵物种与非入侵物种之间的系统发育距离趋向于平均成对距离的入侵物种。这表明，高度入侵的群体可能因其入侵物种具有更平滑且扩张更快的原生分布，并且比入侵性较弱的群体更位于系统发育网络的边缘而被识别出来。
