The Tanggula Mountains enhance population divergence in Carex moorcroftii: a dominant sedge on the Qinghai-Tibetan Plateau

Abstract

High-altitude mountains are often geographic barriers to gene flow and play important roles in shaping population divergence. The central Qinghai-Tibetan Plateau (QTP) stands the location of the Tanggula Mountains (TM). We use the TM as a case, using Carex moorcroftii, a dominant species on the QTP to test the effects of geographic barriers on plant population divergence. We sampled 18 C. moorcroftii populations along a north-south transect crossing the TM to investigate the correlations of genetic variation and morphological traits with climate variables. The results showed this species holds high genetic diversity (He = 0.58) and the surveyed populations can be genetically clustered into two groups: populations from the north face of TM, and the other from the south. Gene flow between populations within groups is higher than those between groups. The traits, number and mass of seeds, mass of root and infructescence significantly varied among populations. Mantel-tests detected a weak but significantly positive correlation between genetic and geographic (R2 = 0.107, p = 0.032) and climatic distance (R2 = 0.162, p = 0.005), indicating both isolation by distance and isolation by environment. These findings together suggest high-altitude mountains of TM interrupt habitat continuity, result in distinct climatic conditions on both sides, increasing population divergence of plant species.

Drivers of population divergence and species differentiation in a recent group of indigenous orchids (Vanilla spp.) in Madagascar

“…Potential ecological drivers of orchid diversification are multiple, such as adaptation to pollinators (Ayasse et al., 2011; Dressler, 1982; Van der Niet et al., 2014), mycorrhizal specificity (Otero et al., 2007), differences in flowering phenology, and floral characteristics (color, form and fragrance) resulting from adaptation to different environmental conditions (Givnish et al., 2015; Pansarin & Ferreira, 2019; Sun et al., 2015) and leading to isolation by ecology. Although the various patterns namely IBD, IBE, and IBA have gained attention in the literature (e.g., Garot et al., 2019; Liu et al., 2018; Noguerales et al., 2016; Orsini et al., 2013; Shafer & Wolf, 2013), few studies have evaluated their joint contribution in orchid species differentiation (e.g., Jaros et al., 2016; Mallet et al., 2014), and no research efforts, to our knowledge, have been invested so far on this subject regarding Vanilla species divergence.…”

Relative importance of isolation‐by‐environment and other determinants of gene flow in an alpine amphibian

“…2000; Liu et al. 2018; Sanchez‐Montes et al. 2018), and in other cases divergence depends on whether the dispersal path passes through particularly high‐ or low‐elevation terrain (Cushman et al.…”

Localized environmental heterogeneity drives the population differentiation of two endangered and endemic Opisthopappus Shih species

“…With peaks reaching ~ 2800 m in elevation, the Taihang Mountains have many deep gullies and immense valleys. Its complex topography serves as a significant geographical barrier in Northern China [ 22 ], which can cause distributional gaps between species, leading not only to disjointed populations but also to cascading effects associated with interrupted gene flow and habitat heterogeneity [ 48 ]. Following limited gene exchange, O. taihangensis and O. longilobus , which are distributed only on the Taihang Mountains, were segmented into spatially isolated subpopulations (Figs.…”