About This Project

Plants convert sunlight into energy and initiate symbiotic partnerships with fungi through their roots. In these symbioses, plant-derived carbon (C) is traded with fungi for water and nutrients. I plan to investigate exactly how C flows through belowground fungal networks in a grassland prairie plot. Determining the fate of C is important in understanding plant-fungal trade systems, but perhaps more so in specifying the relationship between soil fungal C and climate change mitigation.

Ask the Scientists

What is the context of this research?

Belowground carbon (C) is typically poorly understood, and the fate of new carbon and the organisms it is distributed to are almost always unknown. As environmental change factors such as atmospheric CO2 concentration and global nitrogen deposition continue to increase, determining how C-flow dynamics change in response will be critical to predict how ecosystems will function in the future. The close relationship between plants and their symbiotic microbes is regulated by the exchange of various goods and services. Plants tend to allocate more C to fungi that transfer the most nitrogen or phosphorus. Reciprocally, fungi will give the most nutrients to plants that release the most C. My research will help us better understand the changes in these trade relationships by tracking C in soils.

What is the significance of this project?

Tallgrass prairies are one of the most threatened ecosystems on Earth. In the US, they occupy less than 1% of their original land area. Grasslands may have the potential to store huge amounts of carbon (C) belowground in their expansive root systems, but the role of symbiotic fungi in C storage is largely unknown. This project will experimentally track C from individual plants, through their roots, and then into fungal partners in soil. This C found within the plant-associated fungi will be quantified and the fungal species that incorporated the C will be identified. This will help us understand how much C is being transferred to fungi and to which taxa. The results could be used to predict C storage benefits of native prairies, and might help push future restoration efforts.

What are the goals of the project?

This project will begin prior to the peak of the growing season for prairies (mid-summer) in 2017. It will take place at an experimental prairie plot in the midwest, which has been ongoing for ~10 years. I will initiate 13-CO2 pulse-labelling across two experimental treatments at this site; plots are made up of three different cultivars of a prairie grass, Panicum virgatum, and are either unfertilized or fertilized with nitrogen (N). Pulse-labelling is a technique where 'heavy' isotopic carbon (13-C), rather than the normal and 'lighter' 12-C is forced into the plant as atmospheric 13-CO2 (see 'Methods'). I will then track the flow of 13-C considering both time and distance from the plant roots to determine how quickly and how far the new C moves to and through fungi.