Nanofauna (flagellates, amoebae) diversity in relation to land use and ecosystem functioning NANOFAUNA DIVERSITY (NANOFAUN)

原生动物在控制土壤中碳通过细菌的通量中起主导作用，特别是在植物根际和碎屑层中。与纳米原生动物在土壤系统中的基本作用相比，这些最丰富的真核生物在土壤中的多样性只有轶事信息。人们普遍不了解纳米动物的一个主要原因是在不透明的土壤环境中分析小型原生生物的方法上存在困难，以及缺乏分类学专业知识。然而，分子生物学和所谓不可培育原生生物的最新发展，现在允许将纳米动物研究纳入土壤食物网中这一重要营养环节的重要空白。在第一次拨款期间，我们的小组已经为鞭毛虫和变形虫的几个分支开发了新的特异性分子引物，这些引物目前应用于第一个高通量454-测序计划。我们还采用了一种新的土壤同质培养方法，允许对单个克隆进行测序，并对土壤悬浮液进行直接分析。我们准备将这些方法应用于所有150个密集研究的森林样地，以分析鞭毛虫和变形虫的丰度和生物多样性。这些方法的结合现在使我们能够以前所未有的细节获得异养鞭毛虫和裸变形虫多样性的可比估计。这产生了世界上第一个将纳米原生生物作为定量和定性水平上最丰富但研究最少的土壤成分的数据集，与相应的细菌、真菌和许多其他生物和非生物土壤参数（地上和地下）的数据直接相关。缩小细菌和多细胞生物之间的差距应该是我们理解土壤生物多样性的基础。

Protozoa play a dominant role in controlling the flux of carbon through bacteria in soil, in particular in the plant rhizosphere and detritusphere. In contrast to the fundamental role of nanoprotozoa in soil systems there is only anecdotal information on the diversity of these most abundant eukaryotes in soil. One major reason for the general ignorance of nanofauna were methodological difficulties in analysing small protists in the opaque soil environment and the lack of taxonomic expertise. However, recent developments in molecular biology and in the cultivation of so-called uncultivable protists now allow the incorporation of nanofauna studies to close the important gap on this important trophic link in the soil food web. During the first grant period our groups have developed new specific molecular primers for several clades of flagellates and amoebae which are currently applied in a first high through-put 454- sequencing initiative. We also adopted a new aliquot cultivation procedure to soils, allowing sequencing of single clones, and direct analyses of soil suspensions. We are ready to apply these methods on all 150 intensively studied forest plots to analyze the abundance and biodiversity of flagellates and amoebae. The combination of these methods now allows us to obtain comparable estimates of the diversity of heterotrophic flagellates and naked amoebae in unprecedented detail. This generates the first data set worldwide considering nanoprotists as the most abundant but least studied soil component on a quantitative and qualitative level in direct relation to data on corresponding bacteria, fungi, and many other biotic and abiotic soil parameters (above and below ground). Closing the gap between bacteria and multicellular organisms should be fundamental for our understanding of the biodiversity in soil.