Identification of keystone prokaryotic food web members and links in belowground carbon turnover - SP MicLink

森林基金会的MicLink项目旨在精确了解地下食物网细菌成员之间的营养连接和碳流。在第一阶段的资金，我们已经产生了一个独特的矩阵的细菌群落结构和分布在我们的联合实验场网站，部分基于pyrotag测序，并确定了几个主要的植物依赖的细菌食物网成分rRNA-SIP。在下一阶段，我们要解决一个新兴的假设，而原生动物捕食很可能是一个相关的控制植物相关的土壤中的细菌，细菌内捕食，如粘细菌可能是被忽视的重要性，特别是在散装土壤。此外，我们已经初步确定了根际细菌的特定子集，似乎是选择性地动员到更深的区域后，地下水补给事件。这可能代表了表层土壤和深层矿质土壤之间的有机质和营养连通性，但人们对这种连通性仍知之甚少。现在，我们计划使用NanoSIMS在渗漏水中使用经修订的13 C标记的生物质和单细胞回收来量化微生物动员率和通量。此外，我们将继续我们的领域和实验室的联合实验的贡献，现在集中在食草动物与碎屑食物链，并在选定的食物网连接的定量通量。所提供的定性和定量数据的基石微生物食物网的连通性将是一个现实的地下食物网的碳流建模的一个基本前提。

The MicLink project within FOR aims to elaborate a precise understanding of trophic connectivities and carbon flow amongst bacterial members of a belowground food web. In the first phase of funding, we have generated a unique matrix of bacterial community structure and distribution at our joint experimental field site, partly based on pyrotag sequencing, and identified several primary plant-dependent bacterial food web constituents by rRNA-SIP. In the next phase, we want to address an emerging hypothesis that while protozoan predation may well be a relevant control of Bacteria in plant-associated soil, intra-bacterial predation e.g. by Myxobacteria may be of overlooked importance especially in bulk soil. Furthermore, we have preliminarily identified specific subsets of rhizosphere Bacteria that seem to be selectively mobilised to deeper zones upon groundwater recharge events. This could represent an organismic and trophic connectivity between top soil and deeper mineral soils that is still poorly understood. Now, we plan to quantify microbial mobilisation rates and fluxes using amended 13C-labelled biomass and single-cell recovery in seepage water using NanoSIMS. Moreover, we will continue our field and laboratory contribution to joint experiments, focussing now on herbivore vs. detrital food chains, and on quantitative fluxes in selected food web connectivities. The provided qualitative and quantitative data on keystone microbial food web connectivities will be an essential prerequisite for a realistic modelling of carbon flow in belowground food webs.