Responses of arbuscular mycorrhizal fungi to nutrient additions in Southern Ecuador

• Applicant: Professor Dr. Matthias C. Rillig, Ph.D.
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: from 2014 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 244578176

The goal of this project, embedded in PAK 823 and the N cycle bundle, is to enhance the comparatively poor knowledge about arbuscular mycorrhizas (AM) in tropical mountain forest systems in general, and in particular to integrate mycorrhizal responses into ongoing nutrient manipulations (NUMEX; NUtrient Manipulation EXperiment) at the research site in Southern Ecuador. Within this framework, we test hypotheses about the abundance of AM fungi in roots and in the soil (extraradical hyphae) based on the resource balance model. We build on our previous measurements showing rapid responses to fertilization, especially N. Using molecular ecology tools (pyrosequencing) we test for differences in AM fungal assemblages in roots in response to nutrient manipulations and along elevational gradients.Within the N cycle bundle, we coordinate the joint rotated core experiment, in which we can switch off the mycorrhizal influence in order to learn about the effect of these fungi on the N cycle. In addition we contribute to the joint 15-N labeling experiment. We hope this work will make a decisive contribution to our knowledge of AM and the N cycle in this tropical system.

• DFG Programme: Research Grants