Biodiversity of micro-eukaryotes in Antarctic Dry Valley soils with <5% soil moisture
Biodiversity of micro-eukaryotes in Antarctic Dry Valley soils with <5% soil moisture
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DOI：
10.1016/j.soilbio.2006.01.014
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发表时间：
2006-10-01
影响因子：
9.7
通讯作者：
Craig, Scott
中科院分区：
文献类型：
--
作者：
Fell, Jack W.;Scorzetti, Gloria;Craig, Scott
南极洲干旱山谷的土壤被认为是世界上最极端的环境之一。这些土壤古老、寒冷、干燥，有机碳和氮含量低。靠近水（湖泊和融冰）的浮游生物具有重要的生物活性，这表现在藻类垫、地衣和小型无脊椎动物，特别是线虫、缓步动物和轮虫的存在。相比之下，在干旱山谷中有大量的地区非常干燥，含水量低于5%。这些土壤通常是咸的，似乎是贫瘠的生命，因为它们由于缺乏植物有机物质而具有粗糙的质地。相比之下，分子技术（从土壤中提取DNA，克隆和rDNA序列分析）证明存在一个复杂的微型真核生物食物网，其结构和组成随水分含量和位置而变化。土壤中微真核生物群落在0.2-1.3%的水分是由酵母属丝孢酵母和一个未鉴定的微真核生物分支的物种，而从3.1%到4.9%的水平包含复杂的食物网，包括初级生产者（绿藻和层生植物），共生体（地衣相关真菌）、嗜盐菌（真菌）、捕食者（泡孔动物和尾虫）和真菌线虫寄生物/病原体。土壤物种多样性（80种，来自15个站点），在每个站点的有限数量（3-21种）。低水分干谷土壤的敏感和可测量的社区结构提供了一个无与伦比的机会，研究当地和全球环境对微真核生物群落动态与多个营养水平。(c)2006爱思唯尔有限公司保留所有权利。
Soils in the Dry Valleys of Antarctica are considered to be among the world's most extreme environments. These soils are old, cold and dry with low contents of organic carbon and nitrogen. Habitats adjacent to water (lakes and ice melts) have significant biological activity as demonstrated by the presence of algal mats, lichens and small invertebrates, particularly nematodes, tardigrades and rotifers. In contrast, there are extensive areas in the Dry Valleys that are extremely dry with less than 5% moisture content. These soils are often salty and appear to be barren of life as they have a coarse texture due to their lack of plant organic material. In contrast, molecular techniques (DNA extraction from soils, cloning and rDNA sequence analysis) demonstrated the presence of a complex micro-eukaryotic food web whose structure and composition varied with moisture content and location. Micro-eukaryotic communities in soils with 0.2-1.3% moisture were represented by species of the yeast genus Trichosporon and an unidentified clade of micro-eukaryotes, whereas levels from 3.1% to 4.9% contained complex food webs including primary producers (chlorophytes and stramenopiles), symbionts (lichen associated fungi), saprophytes (fungi), predators (alveolates and cercozoans) and fungal nematode parasite/pathogens. The soils had a diversity of species (80 species from 15 sites) with a restricted number (3-21 species) at each site. The sensitive and measurable community structure of the low moisture Dry Valley soils provides an unparalleled opportunity to examine local and global environmental effects on micro-eukaryotic community dynamics with multiple trophic levels. (c) 2006 Elsevier Ltd. All rights reserved.