Anthropogenic environmental changes are known to influence the Earth’s ecosystems. However, how these changes affect assembly trajectories of the impacted communities remains a largely open question. In this study, we investigated the influence of elevated nitrogen (N) deposition and increased precipitation on plant taxonomic and phylogenetic β-diversity in a 9-year field experiment in the temperate semi-arid steppe of Inner Mongolia, China.
Results/Conclusions
We found that both N and water addition significantly increased taxonomic β-diversity, whereas N, not water, addition significantly increased phylogenetic β-diversity. After the differences in local species diversity were controlled using null models, the standard effect size of taxonomic β-diversity still increased with both N and water addition, while water, not N, addition, significantly reduced the standard effect size of phylogenetic β-diversity. The increased phylogenetic convergence observed in the water addition treatment was associated with the colonization of phylogenetically closely related species. Our analyses demonstrate that anthropogenic environmental changes may influence the assembly trajectories of plant communities at both taxonomic and phylogenetic scales. Moreover, our findings indicate that studying phylogenetic β-diversity could provide additional insight into the mechanisms driving community assembly in the face of environmental changes, compared to studies focusing exclusively on species-level β-diversity.