Determinants of global variation in taxonomic and phylogenetic diversity of invasive plants

Information on the determinants of taxonomic and phylogenetic diversity of
invasive plant species is crucial for managing invasive plants. With
globalization, most countries have experienced substantial economic losses
and environmental damage due to biological invasions. We analyzed the
determinants of variation in the diversity and phylogenetic structure of
invasive plants among countries worldwide.  To do so, we used a
comprehensive checklist of invasive plants in 152 countries worldwide to
calculate taxonomic and phylogenetic diversity (i.e., Faith’s PD metric)
and phylogenetic structure, using Mean Phylogenetic Distance (MPD) and
Mean Nearest Taxon Distance (MNTD). We then combined these data in minimum
adequate models with data on geographic, climatic, socio-economic, and
international trade variables. We also conducted randomization tests to
determine whether phylogenetic diversity of invasive plants in these
countries was clustered or overdispersed.  Taxonomic and
phylogenetic diversity of invasive plants exhibited spatial congruence,
both positively correlated with insularity, mean annual precipitation
(MAP), and HS-12 import values per capita, but negatively associated with
mean annual temperature (MAT) and HS-07 import evenness. In addition,
taxonomic diversity also increased with airport density, HS-12 import
evenness, and lower HS-08 imports. MPD increased with greater land area
and airport density, and fewer HS-12 exporting source countries. MNTD
increased with MAT but declined with greater land area and insularity.
Phylogenetic clustering occurred in 28.9–49.3% of countries, whereas
phylogenetic overdispersion was rare, observed only in 0.6–5.3% of
countries.  synthesis. Our study reveals that variation in
taxonomic and phylogenetic diversity of invasive plant species among
countries is shaped by geographic, socio-economic, climatic, and
international trade factors. Nearly one-third of the countries showed
phylogenetic clustering of invasive plant species, indicating a relatively
consistent global pattern. These findings underscore the importance of
integrating both taxonomic and phylogenetic perspectives in invasion
ecology, emphasizing the need for regionally tailored management
strategies that effectively account for regional geographic, climatic,
socio-economic, and trade-related factors to mitigate future plant
invasions.