Bri FinleyGraduate Student
Finley’s research interests involve investigating how human activities affect nutrient cycling in terrestrial systems and possible feedbacks to climate change and greenhouse gas emissions. Her interests range from microbial ecology to global change questions.
She is interested in continuing research to address pressing ecological questions as well as developing outreach programs to connect people outside the scientific community to help solve environmental problems.
Bri Finley says “there’s a whole universe under our feet!” Bri is conducting her research on how soil microbes affect the release of carbon into the atmosphere, and how that may link to climate change. A PhD candidate in Bruce Hungate’s Lab at Ecoss, Bri came to NAU from San Diego as an undergraduate to be closer to wild, open spaces. During her work at NAU she became so interested in microbes that she decided to continue to work with them and eventually, to pursue her PhD with a focus on soil microbes. Microbes are extremely small organisms that can only be seen with a microscope.
Bri’s research takes her to the Sierra Nevada Mountain Range in California (see photo). There, within a single ecosystem, she finds two very different soil types that are built on different rock types: granite and andesite. Andesite is a poorly-weathered volcanic ash and has large amounts of amorphously shaped non-crystalline materials in which the atoms and molecules are not organized in a definite ordered pattern. This complex shape allows the soil derived from andesite to hold up to three times as much carbon within it as compared to soils derived from crystalline granite. This is important because the carbon stored within the andesite is therefore more “protected” from consumption by microbes, thus creating the perfect study system to determine if changing climate may release this carbon from the soil.
One of Bri’s research experiments involves conducting a “priming” experiment, in which she will mimic a shift in the sugars, amino acids and organic acids that leak out from plant roots by adding sugars to the two soil types. This work, conducted in the lab, will allow Bri to determine if the carbon currently being held by the two soil types is released with the changing conditions. The results will improve our understanding of how different soil types release carbon into the atmosphere with changing climate conditions. The second part of Bri’s research involves adding oxalic acid and glucose to the two soil types to determine how this affects the carbon accessibility of the soils. This experiment will include using qSIP (Quantitative Stable Isotope Probing) to identify the specific microbes that may be driving the change.
Bri is excited to be working with soil microbes. She says that scientists are on the cusp of being able to answer big questions about the role microbes play in the storage and release of carbon into the atmosphere and the effects this will have on climate change.
Biological and mineralogical controls over soil carbon cycling across multiple ecosystems: a focus on the priming effect