Protists in the soil food web of an arable field:Their density, taxonomic composition and functional role in carbon flux

作者：Maike Hünninghaus · 年份：2014 · 研究领域：Soil Carbon and Nitrogen Dynamics、Peatlands and Wetlands Ecology、Legume Nitrogen Fixing Symbiosis

Soil ecosystems are of fundamental importance for global carbon (C) cycling because they are the largest sinks and sources of terrestrial C. Therefore a detailed understanding of C fluxes through soil food webs is essential to predict ecosystem responses to anthropogenic CO2 enrichment of the atmosphere. Because organic C is also fundamental to the fertility of arable soils understanding of C cycling is inevitable to develop sustainable soil management strategies. Organic C enters the soil system via two different main routs: it is constantly released by plant roots in form of rhizodeposits and it enters the soil as dead organic matter (detritus). In both pathways C is directly acquired by diverse and highly active microorganisms. However, the C flux through microbial food webs is largely unknown predominantly due to the complex nature of trophic interactions. This PhD thesis is focusing on the functional role of protozoa in the rhizosphere and detritusphere of agricultural systems. Protozoa being at the base of soil food webs are assumed to be key-players in controlling the C flux from bacteria to higher trophic levels. Nevertheless the community composition in soil is largely unknown and the ecological importance of different protozoan taxa is even less understood. One aim of this thesis was to get deeper insights to the taxonomic composition and density of protozoan communities in arable soils. First the microbial food web was characterized at different soil depth an...