Biodiversity Research Center, Academia Sinica, Nankang, Taipei, Taiwan.
Microb Ecol. 2010 Feb;59(2):369-78. doi: 10.1007/s00248-009-9574-0. Epub 2009 Sep 2.
The diversity and composition of soil bacterial communities in three topographic sites (summit, foot slope, and lakeshore) from subtropical montane forest ecosystem in Taiwan were examined by using 16S rRNA gene clone library analysis. This locality is temperate, perhumid, and has low soil acidity (pH < 4), which is an uncommon ecosystem in a monsoonal part of Southeast Asia. A total of 481 clones were sequenced and placed into ten phylogenetic groups according to their similarities to type strains of described organisms. Toposequence of the transect was investigated from summit to foot slope and at the lakeshore. More than 86% of the clones were affiliated with members of the Proteobacteria, Acidobacteria, and Actinobacteria. Within the Proteobacteria, the beta-Proteobacteria was the most abundant, then alpha-Proteobacteria and gamma-Proteobacteria. Based on the Shannon diversity index (H) analysis, the bacterial community in the foot slope was the most diverse (H = 0.86) and that in summit was the least diverse (H = 0.68). The composition and diversity of soil bacterial communities in the three sites suggested no trend with topographic change. Less than 20% of the sequences were Acidobacteria-affiliated clones. The low proportion of Acidobacteria observed may be related to the high soil moisture and anaerobic microhabitats. Moreover, Shannon diversity indices revealed these bacterial communities to have lower diversity than that of other temperate (H = 0.90) and tropical forest (H = 0.82) ecosystems. The extreme acidity of soil pH and high soil moisture of this forest may explain composition and reduced the diversity of these soil bacterial communities.
采用 16S rRNA 基因克隆文库分析的方法，研究了台湾亚热带山地森林生态系统中三个地形位置（山顶、山坡和湖滨）的土壤细菌群落的多样性和组成。该地区气候温和、湿润，土壤酸度低（pH<4），这在东南亚季风地区是一种罕见的生态系统。共测序了 481 个克隆，并根据与描述生物的标准菌株的相似性将其分为十个系统发育群。从山顶到山坡和湖滨对该地区的地形序列进行了调查。超过 86%的克隆与变形菌门、酸杆菌门和放线菌门的成员有关。在变形菌门中，β-变形菌门是最丰富的，其次是α-变形菌门和γ-变形菌门。根据 Shannon 多样性指数（H）分析，山坡上的细菌群落多样性最高（H=0.86），山顶上的细菌群落多样性最低（H=0.68）。三个地点土壤细菌群落的组成和多样性没有随地形变化的趋势。不到 20%的序列与酸杆菌门有关。观察到的酸杆菌门比例较低可能与高土壤湿度和厌氧小生境有关。此外，Shannon 多样性指数表明，这些细菌群落的多样性低于其他温带（H=0.90）和热带森林（H=0.82）生态系统。土壤 pH 值的极端酸度和森林高土壤湿度可能解释了这些土壤细菌群落的组成和降低了多样性。
