Biodiversity Research Center, Academia Sinica, Nankang, Taipei, 11529, Taiwan.
Mackay Junior College of Medicine, Nursing and Management, Beitou, Taipei, 11260, Taiwan.
Sci Rep. 2019 Mar 20;9(1):4689. doi: 10.1038/s41598-019-41170-9.
The effects of biogeographical separation and parent material differences in soil bacterial structure and diversity in offshore islands remain poorly understood. In the current study, we used next-generation sequencing to characterize the differences in soil bacterial communities in five offshore subtropical granite islands (Matsu Islets, MI) of mainland China and two offshore tropical andesite islands (Orchid [OI] and Green Islands [GI]) of Taiwan. The soils of OI and GI were more acidic and had higher organic carbon and total nitrogen content than MI soils. The bacterial communities were dominated by Acidobacteria and Proteobacteria but had different relative abundance because soils were derived from different parent material and because of geographic distance. Non-metric multi-dimensional scaling revealed that the communities formed different clusters among different parent material and geographically distributed soils. The alpha-diversity in bacterial communities was higher in tropical than subtropical soils. Mantel test and redundancy analysis indicated that bacterial diversity and compositions of OI and GI soils, respectively, were positively correlated with soil pH, organic carbon, total nitrogen, microbial biomass carbon and nitrogen. These results suggest that variations in soil properties of offshore islands could result from differences in soil parent material. Distinct soils derived from different parent material and geographic distance could in turn alter the bacterial communities.
生物地理隔离和母质差异对近海岛屿土壤细菌结构和多样性的影响仍知之甚少。本研究采用下一代测序技术，对中国大陆五个近海亚热带花岗岩岛屿（妈祖列岛，MI）和中国台湾两个近海热带安山岩岛屿（兰花屿[OI]和绿岛[GI]）的土壤细菌群落差异进行了表征。OI 和 GI 的土壤酸度较高，有机碳和全氮含量也较高。细菌群落主要由 Acidobacteria 和 Proteobacteria 组成，但由于土壤来源于不同的母质，且地理位置不同，其相对丰度也有所不同。非度量多维尺度分析显示，不同母质和地理分布的土壤形成了不同的群落聚类。热带土壤的细菌群落 alpha 多样性高于亚热带土壤。Mantel 检验和冗余分析表明，OI 和 GI 土壤的细菌多样性和组成分别与土壤 pH 值、有机碳、全氮、微生物生物量碳和氮呈正相关。这些结果表明，近海岛屿土壤性质的变化可能是由于土壤母质的差异造成的。不同母质和地理位置的不同土壤反过来又会改变细菌群落。
