Student: Alexandra Grajales, PhD graduate student in Geology, Iowa State University
Faculty Advisor: Professor Benjamin Johnson
Stable Isotope Analysis of Fossilized Plants for C cycling and N soil Availability during the Phanerozoic
On Earth today, plants comprise the vast majority of fixed carbon in biomass and plant growth may be limited by bioavailable N. Studying the evolution of the terrestrial C cycle depends on understanding how plants fixed C and the availability of N in their environments. The relationship between C and N may reflect a combination of atmospheric isotopic signatures of CO2 and soil N availability. By cultivating plants in growth chambers with various CO2 and N2 fluctuating conditions, we can track plant adaptability and compare isotope plant tissue concentrations through time. I will periodically sample plant material throughout the experiment to track how plant growth can vary and how different concentrations of CO2 are stored within plant tissue. Also, I will track nitrogen and nutrient availability in the soil to understand the effect that strenuous conditions can have on the microbial communities that contribute to plant nutrient uptake. This research will allow for a deeper understanding of how plant tissues adapt to environmental changes in trying conditions and can be directly applied in growth chambers experiments done in space. It will open doors to studying plant adaptability and the minimal conditions needed for efficient plant growth on Earth and in space.