Abstract
Recently, ecologists have become aware that, despite being separated in space, aboveground and belowground organisms can influence each other via changes in plant quality and plant defense compounds. Most aboveground-belowground studies have been with individuals of root and shoot associated organisms and isolated plants. In nature, however, plants are associated with multitrophic communities, but how aboveground and belowground interactions are expressed under natural conditions is not known. Moreover, in natural conditions plants usually coexist in mixed plant communities and interactions between plants and multitrophic communities are also influenced by interactions that occur on other plants. My aim is to elucidate how aboveground and belowground communities associated to individual plants are influenced by host plant quality and the surrounding multitrophic community. In natural grasslands, I will study aboveground and belowground communities associated to the plant ragwort and elucidate how multitrophic interactions on this plant are influenced by plant quality and by the surrounding multitrophic community. I will use genotypes of ragwort that differ in plant quality. I will use an on-going biodiversity experiment to study the relationship between vegetation, soil biodiversity and aboveground invertebrates, and in a separate field experiment will manipulate the diversity of the surrounding plant community, and carry out plant-soil feedback studies to determine the effects of plant diversity and identity on these interactions. Aboveground, I will focus on flower-feeding and leaf-mining insect communities and construct quantitative interaction foodwebs. Soil organisms will be identified using novel molecular techniques and this will provide reliable information on abundance of soil microorganisms such as nematodes, bacteria and fungi. Plant quality aspects will be determined using targeted and non-targeted (metabolomics) approaches. By combining molecular, plant chemical and ecological approaches this project will provide a comprehensive understanding of multitrophic interactions between soil organisms, plants and aboveground invertebrates as they occur in natural conditions.
Netherlands