Presenter: Emily Scherer – Biology
Faculty Mentor(s): Hilary Rose Dawson, Lucas Silva
Session: (In-Person) Poster Presentation
Enhanced silicate weathering (ESW) is emerging as a top contender to reduce atmospheric carbon and mitigate climate change by accelerating soil C sequestration. However, little is known about ESW’s potential for success on global and regional scales. Applying basalt dust to soil can draw down atmospheric C, boost nutrient availability for crops, and counter soil acidification, yet it may also heighten microbial activity and release soil C via respiration. Arbuscular mycorrhizae (AM), ectomycorrhizae (EcM), and plant community composition can also alter weathering rates. Our research tests soil respiration rates in the presence of basalt dust and mycorrhizal associations in local Willamette Valley soils. We hypothesize that respiration will increase due to the fertilizing effects of basalt but that a faster pace of weathering will result in a net C sink. We predict that respiration and sequestration will be greatest in the presence of EcM fungi. To test this theory, we potted four tree species, each known to form an AM or EcM relationship, in soil mixed with none, low or high concentrations of basalt dust. We measured baseline soil pH, initial C stocks, and nutrients. Currently, we are measuring respiration using a soil CO2 flux chamber. As the project advances, we will measure changes to these variables, plant biomass, and inorganic C stocks. This study will contribute to the literature regarding the potential of ESW to offset anthropogenic C emissions.