Abstract:

A database of alien flora is important for better understanding the patterns of plant invasions, as well as explicating the mechanisms promoting plant invasion at local, regional and global scales. However, little attention has been paid to the construction of such a database of terrestrial alien herbs in China. Here, we attempt to summarize literature and reveal chronological and biogeographical patterns of alien herbaceous plant invasions. In total, 800 herbaceous alien species were identified, belonging to 37 orders and 72 families, ten families which account for 60% of the total flora. The families containing large numbers of species include Asteraceae, Fabaceae, Cactaceae, Poaceae and Brassicaceae. Species originating from the Americas made up 47% of total species. In relation to life forms, most species are perennial herbs (293 species, 40%) and annuals (272 species, 37%). About 46% of species are often found in highly disturbed habitats with rich resources. Our results suggest that, in China, terrestrial alien herbs are distributed throughout the entire country, with particularly high species richness in the Southeast (23% of total richness, 4 species per 10,000 km²). Eighty percent of alien plants were introduced into China intentionally, and there has been a steady increase in the number of neophyte species over the last two centuries, of which about 90% were introduced after 1800s and 60% post-1950s. The information on diversity and ecological characteristics of terrestrial alien herbs provided in this paper can be used for designing national management strategies for alien plants in China.

Key words: diversity, terrestrial herbs, alien species, China