Proximate grassland and shrub-encroached sites show dramatic restructuring of soil bacterial communities

PeerJ

article

Xingjia Xiang¹  Sean M. Gibbons²  He Li³  Haihua Shen⁴  Haiyan Chu⁵ 

[1] Anhui Province Key Laboratory of Wetland Ecological Protection and Restoration, School of Resources and Environmental Engineering, Anhui University;Institute for Systems Biology;School of Geography, Geomatics and Planning, JiangSu Normal University;State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences;State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences

关键词: Shrub encroachment;    Bacterial community;    Grassland ecosystem;    Niche filtering;    Sequencing;   

DOI  :  10.7717/peerj.7304

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Background Changes in aboveground community composition and diversity following shrub encroachment have been studied extensively. Recently, shrub encroachment was associated with differences in belowground bacterial communities relative to non-encroached grassland sites hundreds of meters away. This spatial distance between grassland and shrub sites left open the question of how soil bacterial communities associated with different vegetation types might differ within the same plot location. Methods We examined soil bacterial communities between shrub-encroached and adjacent (one m apart) grassland soils in Chinese Inner Mongolian, using high-throughput sequencing method (Illumina, San Diego, CA, USA). Results Shrub-encroached sites were associated with dramatic restructuring of soil bacterial community composition and predicted metabolic function, with significant increase in bacterial alpha-diversity. Moreover, bacterial phylogenic structures showed clustering in both shrub-encroached and grassland soils, suggesting that each vegetation type was associated with a unique and defined bacterial community by niche filtering. Finally, soil organic carbon (SOC) was the primary driver varied with shifts in soil bacterial community composition. The encroachment was associated with elevated SOC, suggesting that shrub-mediated shifts in SOC might be responsible for changes in belowground bacterial community. Discussion This study demonstrated that shrub-encroached soils were associated with dramatic restructuring of bacterial communities, suggesting that belowground bacterial communities appear to be sensitive indicators of vegetation type. Our study indicates that the increased shrub-encroached intensity in Inner Mongolia will likely trigger large-scale disruptions in both aboveground plant and belowground bacterial communities across the region.

【 授权许可】

CC BY