Fig. 3.

NTI (red triangle) for introduced (left), naturalized (middle), and invasive (right) angiosperm species for China as a whole and for each of the eight selected province-level regions, with respect to their respective national and provincial species pools. Species pool for introduced species included all (i.e., native and introduced) species; species pool for naturalized species included introduced species only; species pool for invasive species included naturalized species only. Species pools for different plant groups in each province-level region included only respective species (i.e., all, introduced, naturalized) in the region. Each histogram represents the frequency of NTI values derived from 999 null assemblages randomly drawn from the species pool.