A complete inventory of Earth’s biological communities would provide crucial information for conserving biodiversity and for sustainable use of natural resources. Even though forest is one of the world’s well-described ecosystems, efforts to enumerate forest communities based on their species composition have been lacking in some regions of the world. In the meantime, alien species are spreading (for example, Aung and Koike, 2015) and forest vegetation types are changing due to the creation of ‘‘novel ecosystems” composed of these species (Martinuzzi et al., 2013).