General laws of biological invasion based on the sampling of invasive plants in China and the United States

A comparative analysis of invasive plants in China and the USA, the climates of which are similar, revealed both similarities and differences in taxonomic characteristics, morphological characteristics, areas of origin, invaded regions, and histories of introduction. Generally, there were more species from Asteraceae and Poaceae than from other families, and a high proportion of families were represented by only one invasive species. Most invaders had at least one reproductive mode, with sexual reproduction being the main mode, as well as the adaptation of flower, fruit, and seed characteristics for successful seed production and dispersal. Many invasive plants are able to reproduce clonally. An analysis of the invasive species in China and the USA indicated that they are mainly derived from continents with climates similar to that of the invaded area or at latitudes within the same range. Species from tropical areas invaded more easily than those from other climatic zones. Our study of the invasive histories of species introduced into China and the USA demonstrates that it takes about 100 years for an exotic species to become an invasive species. Keywords: Distribution, Invasibility, Invasive capacity, Introduction history, Alien species