Conclusion
The results of this study suggested that the annual ephemeral species
adapt to the common effects of environmental filtration and
interspecific competition through convergence or divergence of root
system architecture traits. Additionally, the divergence of plasticity
of traits related to resource acquisition (e.g. SRL, SRA) and the
convergence of soil space exploration methods (e.g. TI) play an
important role in the process of adapting to highly heterogeneous desert
habitats. The evolutionary history of species significantly affects the
development of MRD in annual ephemerals. The LMF reflects the water
demand of plants, while the RMF is the foundation for root exploration
of soil space. Although root trait variation patterns and biomass
allocation are important ecological indicators reflecting root
adaptation to the environment, the impact of phylogenetic relationships
is equally important.