Blow to the Northeast? Intraspecific differentiation of Populus davidiana suggests a northeastward skew of a phylogeographic break boundary in East Asia

Aim: There is increasing interest in the role that biological traits, and historical and biogeographic processes, play in the formation of phylogeographic patterns. An arid belt that once existed in northern China might have affected many plants, but this has yet to be untested in an arid-tolerant, wind-dispersed species. Here we tested how intrinsic and extrinsic factors have affected the phylogeography of Populus davidiana.

Location: East Asia

Methods: Genetic variation was surveyed across 40 populations (555 individuals) covering the Chinese range of P. davidiana, using 16 nuclear microsatellite loci (nSSRs) and four chloroplast fragments (cpDNA). Demographic and migration hypotheses were tested using coalescent-based approaches, and the present and past potential distributions were predicted using species distribution modelling.

Results: Molecular data divides P. davidiana into two lineages, northeastern China (NECR), and central and northern China (CNCR); however, the divi...