Distributional Patterns of Alien Plants in China: The Relative Importance of Phylogenetic History and Functional Attributes

Distribution patterns of alien species in nonnative ranges might be driven by a combination of various mechanisms, including phylogenetic history, competition for resource, environmental filtering, and so on. Both phylogenetic and functional limitations might work synergistically to determine the distribution of alien species. In this report, by utilizing the information of provincial distribution, functional attributes, and phylogeny for 95 alien species of China, the corresponding phylogenetic and functional community structures are evaluated. The results show that introduction pathway, life form, and flowering time of alien plants of China processed significant phylogenetic clustering patterns, while both the origin of distribution and reproduction mode of alien species showed phylogenetic overdispersion patterns, as revealed by NRI/NTI indices. The phylogenetic signal tests using Pagel’s statistic and Blomberg et al.’s statistic further verified the previous patterns, even though there are some inconsistencies. Through partial Mantel test, it is found that compositional patterns of alien plant community were mainly affected by phylogenetic limitation but not functional limitation. Conclusively, phylogeny plays a more important role in structuring provincial distribution of alien plants in China. 1. Introduction Alien species may possess novel functional traits for successful colonization of new habitats, in addition to random events or similar traits to native species [1–3]. However, some recent studies have pointed out that phylogeny is also playing some role on influencing alien diversity and distribution patterns [4–7]. Functional attributes and phylogenetic history reflected different facets of biological diversity, and the growing trend in ecological studies nowadays is to combine both to address the questions related to the diversity [8–10], distribution [11], and ecosystem functioning [12, 13]. The application of combining both functional and phylogenetic filtering simultaneously to understand the distributional pattern of alien species in nonnative ranges has been concerned in recent studies [14]. It would be of great value to explore their interplay using alien species as the studied model. Alien species have expanded their distributional ranges in recent decades due to globalization and modernization [15], the processes of which required the rapid ecological adaptation [16, 17]. The rapid range expansion indicated the functional uniqueness or commonness of traits when compared alien and native plants [1, 3]. At another perspective, in