Land use effects on insect root herbivores and their interactions with arbuscular mycorrhiza


Scientific investigator:

Prof. Dr. Susanne Wurst

Dr. Ilja Sonnemann

(Freie Universität Berlin)

Insect root herbivores and arbuscular mycorrhizal fungi (AMF) have been demonstratedto be important drivers of plant diversity and productivity. Nonetheless, there is anextreme lack of knowledge about the factors influencing their abundance and diversity.Since the quality of plant tissue for herbivores differs between plant species, we predict that changes in the composition of plant communities affect insect root herbivores. Insect root herbivores on the other hand are likely to affect  AMF communities by altering the availability of photosynthetically fixed carbon. Ultimately, changes in AMF communities caused byinsect root herbivory may feed back on the structure of plant communities. The Biodiversity Exploratories provide an excellent opportunity to explore these reciprocal relationships between plant diversity, root herbivores and AMF along gradients in land use intensity. Our main hypotheses are (1) that differences in plant diversity and soilnutrient level, brought by gradients in land use intensity, influence the abundance anddiversity of insect root herbivores, (2) that insect root herbivory influences the abundance and diversity of AMF and (3) that changes in the abundance and diversity ofAMF caused by insect root herbivory feed back on the structure of plant communities.Additionally to observational field work (hypothesis 1), we will conduct greenhouse experiments (hypotheses 2 and 3) to obtain a deeper understanding on how these soil organism groups interact with each other.