The role of geographic distance in shaping belowground microbial community composition in a long-term field experiment of soil transplantation

In this study, we report a large-scale soil transplantation experiment, whereby the same two soils (red soil and purple soil) were placed in two geographic locations of ~ 1000 km apart in China: Yingtan and Fengqiu in mid-subtropical and warm temperate regions, respectively. The resulting soil microbial communities were assessed 20 years after the soil transplantation, using the 454 pyrosequencing technique based on the analysis of 16S and 18S ribosomal genes. Results show that both the prokaryotic and eukaryotic microorganisms are primarily grouped by the factor of geographic location rather than soil type, and are closely related to microbial communities in the local soil (i.e., Chao soil in Fengqiu). The data suggest that the historical effects persistent in soil microbial communities can be largely erased by 20 years of contemporary disturbance, including changes of climate conditions, implicating a weak effects of historical contingencies on microbial community composition.

本研究报道了一项大规模土壤移植实验：将红壤与紫壤两种土壤，分别放置于中国相距约1000公里的两个地理区域——鹰潭与封丘，二者分别处于中亚热带与暖温带气候区。土壤移植20年后，我们基于16S与18S核糖体基因的分析，采用454焦磷酸测序技术对移植土壤的微生物群落进行了检测。结果显示，原核与真核微生物群落的聚类主要受地理区位因素驱动，而非土壤类型，且与当地原生土壤（封丘地区的潮土）的微生物群落高度相似。本研究数据表明，土壤微生物群落中留存的历史遗留效应，可通过20年的现代环境扰动（包括气候条件变化）大幅消除，这暗示历史偶然性对微生物群落组成的影响相对微弱。