Insights Into the Significance of the Chinense Loess Plateau for Preserving Biodiversity From the Phylogeography of Speranskia tuberculata (Euphorbiaceae)

Abstract

The significance of the Chinese Loess Plateau (CLP) in maintaining biodiversity for northern China has rarely been shown, as previous phylogeographic studies are mostly woody species and they have revealed that Quaternary refugia are mainly located in mountain regions. We selected a drought-enduring endemic herb, Speranskia tuberculata (Euphorbiaceae), to determine its glacial refugia and postglacial demographic history. To this end, we sampled 423 individuals from 38 populations covering its entire geographic distribution. Three chloroplast DNA (cpDNA) fragments, two low-copy nuclear genes, and six nuclear microsatellites (nSSRs) were used and supplemented with ecological niche modeling (ENM) to infer the phylogeographic history of this species. Populations with private haplotypes and high haplotype diversity of cpDNA are mainly located in the CLP or scattered around northeastern China and the coastal region. Spatial expansion, detected using a neutrality test and mismatch distribution, may have resulted in a widely distributed ancestral cpDNA haplotype, especially outside of the CLP. For nuclear DNA, private haplotypes are also distributed mainly in the CLP. In nSSRs, STRUCTURE clustering identified two genetic clusters, which are distributed in the west (western cluster) and east (eastern cluster), respectively. Many populations belonged, with little to no admixture, to the western cluster while (hardly) pure populations of the eastern cluster were barely found. Genetic differentiation is significantly correlated with geographic distance, although genetic diversity is uniformly distributed. ENM suggests that the distribution of S. tuberculata has recently expanded northwards from the southern CLP, whereas it has experienced habitat loss in the south. Thus, S. tuberculata populations probably survived the last glacial maximum (LGM) in the southern CLP and experienced post-glacial expansion. Wind-dispersed pollen could bring the majority of genotypes to the front during spatial expansion, resulting in uniformly distributed genetic diversity. Based on evidence from molecular data and vegetation and climate changes since the LGM, we conclude that drought-enduring species, especially herbaceous species, are likely to have persisted in the CLP during the LGM and to have experienced expansion to other regions in northern China.

Associations between Surface Deformation and Groundwater Storage in Different Landscape Areas of the Loess Plateau, China

“…The Loess Plateau is one of the four chief plateaus in China and has the largest loess accumulation district in the world [1]. The Loess Plateau is rich in resources and provides Land 2024, 13, 184. https://doi.org/10.3390/land13020184 https://www.mdpi.com/journal/land an important ecological habitat for biodiversity [2]. In recent years, the uncontrolled development of coal and groundwater mineral resources and population increases have resulted in the ecological environment deteriorating severely [3].…”

Biologically Active Copmounds in the Exrtacts of Speranskia Tuberculata (Bunge) Baill and Their Effect on the Viability of Cancer Cells of Five Different Lines

“…is a typical example. It is a perennial herbaceous plant that is endemic to Northeast China and grows on grassy slopes, meadows, or thickets, usually in dry places, 300-1900 m in height [2,3]. Speranskia tuberculata is a drought-resistant plant.…”

“…Accordingly, there are fewer and fewer areas of natural, wild growth of this plant. Nevertheless, it is pretty widespread in many Chinese provinces, such as Anhui, Hebei, Henan, Jilin, Liaoning, Nei Mongol, Ningxia, Shaanxi, Shandong and Shanxi [3].…”