Abstract
Soil ecosystems contain extremely species rich communities consisting of microbial populations (bacteria, fungi), microbial grazers (protozoa, nematodes, insects, mites), predators (nematodes, insect, mites), and all other kinds of animals, mostly feeding on several trophic levels, such as enchytraeids and earthworms. Together, these organisms create complex networks of trophic interactions in the form of food webs. Although the higher trophic levels of such food webs have been well characterized, leading to models of food web dynamics, such models are inherently inaccurate and lack strong predictive value, chiefly due to the fact that they lump the diversity of organic substrates and that of microbial decomposers into large functionally incoherent groups. The research proposed here seeks to define the energy and nutrient flows under realistic environmental conditions through these microbial levels of the soil food web and track how energy and nutrients are passed on to higher trophic levels, thereby incorporating the geochemical processes governed by microbial diversity into more informative and mechanistically sound food web models. The project will utilize well characterized field sites, state-of-the-art stable isotope probing and high throughput molecular methods of microbial community analysis, as well as extensive food web model design and testing. In this way, the novel empirical data generated will transform and improve soil food web models, thereby dramatically improving their accuracy and usefulness in predicting the effects of changes in land use on ecosystem functioning.
Netherlands