Moderate grazing promotes genetic diversity of Stipa species in the Inner Mongolian steppe

Abstract

Context Disturbances may affect the spatial patterns of plant genetic diversity, but these effects are not yet well understood for lack of direct experimental evidence. Grazing is one of such environmental disturbance factors which may lead to small-scale spatial heterogeneity in natural grasslands. Objectives Our main goal was to determine whether a grazing disturbance alters population genetic diversity and genetic structure of the dominant species in the Inner Mongolia Steppe. Methods We performed inter-simple sequence repeat (ISSR) molecular marker analysis on populations of Stipa grandis and S. krylovii which were exposed to five consecutive years of varying degrees of grazing disturbance. Results The amplification results showed that the genetic diversity of both S. grandis and S. krylovii populations varied under different grazing intensities; the highest diversity (Nei's index and Shannon's index) were under moderate disturbance, whereas the lowest under the heavy grazing. The coefficient of gene differentiation (G ST ) of S. grandis and S. krylovii populations were 16.82 and 21.00°%, respectively. These results suggest that the genetic diversity of these two dominant populations was altered by the smallscale grazing disturbance, which provides new evidence supporting the theories of landscape genetics. Conclusions The enhancement of moderate grazing on genetic diversity implies the necessity to involve animal grazing in the design of management regimes for biodiversity conservation of the Inner Mongolia steppes.

De novo assembly, annotation, marker discovery, and genetic diversity of the Stipa breviflora Griseb. (Poaceae) response to grazing

“…Anthropogenic activity, such as grazing, can increase, decrease, or have no significant effects on the genetic diversity of plants. In the genus Stipa, moderated grazing was found to promote the genetic diversity of S. grandis and S. krylovii [24]. Similar results were detected in the study by Shan et al [25], and the genetic diversity of S. grandis under light grazing conditions was higher than that under no grazing.…”

Towards a better understanding of landscape patterns and ecosystem processes of the Mongolian Plateau

“…Peng et al (2015) investigated whether grazing would also affect plant genetic diversity in a natural grassland in Inner Mongolia, a question related to landscape genetics. They found that the genetic diversity of two dominant species (Stipa grandis and S. krylovii) varied under different grazing intensities: the highest genetic diversity was found under moderate grazing, whereas the lowest genetic diversity was associated with heavy grazing.…”

Reduced fine-scale spatial genetic structure in grazed populations of Dianthus carthusianorum

“…Because rotational sheep grazing can provide effective seed dispersal and gene flow at the landscape-scale (Rico et al, 2012;Rico et al, 2014b), sheep grazing might also influence the development of fine-scale spatial genetic structure within grazed patches. Experimental studies that have quantified the effects of grazing on the strength of SGS suggest that intensive grazing can negatively impact levels of genetic diversity within populations (Ma et al, 2014;Peng et al, 2015). The effect of grazing on SGS in empirical systems has rarely been studied, and results from available studies are mixed.…”