Climate Reconstruction from Cell Structure in California Oaks
Adam Johnston
School of the Environment
Faculty Supervisor: Alexander Stine
Measurements of tree ring growth have played an important role in our reconstruction of the climate in the last 2,000 years. Traditionally, climate reconstructions have been derived from measuring the width of annual growth rings in gymnosperm species. The geometry of wood cells also encodes information about the environmental conditions the tree grew in. My research draws from measurements of the vascular structure in California oak trees to more accurately reconstruct hydrological climate from tree ring growth. In my work, I am developing a machine learning framework that extracts climate signals from high-resolution images of California native ring-porous oaks. This framework identifies and outlines vascular structure to build a proxy for past climate. The goal of my work is to derive a new method to more accurately reconstruct hydrological climate from tree ring growth. My work has a special focus on Quercus kelloggii in the western Sierra Nevada Mountain Range.