Bacterial Diversity and Community Composition Distribution in Cold-Desert Habitats of Qinghai-Tibet Plateau, China.

Wei Zhang,Binglin Zhang,Tuo Chen,Ali Bahadur,Wasim Sajjad,Guangxiu Liu,Gaosen Zhang,Xiukun Wu,Fahad Nasir

doi:10.3390/microorganisms9020262

Abstract

Bacterial communities in cold-desert habitats play an important ecological role. However, the variation in bacterial diversity and community composition of the cold-desert ecosystem in Qinghai–Tibet Plateau remains unknown. To fill this scientific gape, Illumina MiSeq sequencing was performed on 15 soil samples collected from different cold-desert habitats, including human-disturbed, vegetation coverage, desert land, and sand dune. The abundance-based coverage estimator, Shannon, and Chao indices showed that the bacterial diversity and abundance of the cold-desert were high. A significant variation reported in the bacterial diversity and community composition across the study area. Proteobacteria accounted for the largest proportion (12.4–55.7%) of all sequences, followed by Actinobacteria (9.2–39.7%), Bacteroidetes (1.8–21.5%), and Chloroflexi (2.7–12.6%). Furthermore, unclassified genera dominated in human-disturbed habitats. The community profiles of GeErMu, HongLiangHe, and CuoNaHu sites were different and metagenomic biomarkers were higher (22) in CuoNaHu sites. Among the soil physicochemical variables, the total nitrogen and electric conductivity significantly influenced the bacterial community structure. In conclusion, this study provides information regarding variation in diversity and composition of bacterial communities and elucidates the association between bacterial community structures and soil physicochemical variables in cold-desert habitats of Qinghai–Tibet Plateau.

Highlights

The cold-desert ecosystem in the northeastern Qinghai–Tibet Plateau is geographically and ecologically distinct
Regardless of the cold and dry nature of the Qinghai–Tibet Plateau desert soils, this study found a relatively high diversity within bacterial community composition
This study provides the first insight into bacterial communities associated with humandisturbed, vegetation coverage, desert land, and sand dune habitats across the desert soil

Summary

Introduction

The cold-desert ecosystem in the northeastern Qinghai–Tibet Plateau is geographically and ecologically distinct. Despite considered an extreme region compared to the surrounding areas, little is known about its microbial diversity and community composition. In addition to extreme fluctuations in annual temperature, other environmental factors, such as low nutrient availability, low-soil-moisture content, and elevated ultraviolet (UV) radiation make the area extremely arid [1,2,3,4,5]. Cold-desert habitats are proposed to reduce the potential productivity of soil or cause destruction of soil system functioning and support relatively simple ecosystems, including food-web structures comprised of cold-adapted plants and microbial taxa [6]. Soil microbial diversity and community functions are greatly affected by complex environmental variations [4,9]

Methods

Results

Discussion

Conclusion