Postdoctoral Researchers
Dr. Jiaming (Jamie) Duan: Jamie, originally from Henan, China, earned her Ph.D. in Biological Systems Engineering from the University of Nebraska-Lincoln. She is dedicated to leveraging modeling and remote sensing tools to estimate soil carbon, water, and nitrogen cycling, contributing to data-driven decision-making in sustainable agricultural and environmental management. Jamie is currently co-leading the improvement of the RCTM system.
Dr. Ye Yuan: Ye, originally from Jiangsu, China, earned her Ph.D. in Earth System Modeling from Purdue University. Her research focuses on developing and applying Earth system models, including process-based and AI-driven approaches, to study global carbon and nitrogen dynamics and gas fluxes, with particular attention to their responses to environmental factors and anthropogenic activities. Ye is currently co-leading the Farm Practice model intercomparison project.
Ph.D. Students
Alexandra Crookshanks is a PhD student in the Department of Earth and Environmental Sciences at Columbia University. She received a B.S in Environmental Science from Indiana University and a M.S. in Earth and Environmental Engineering from Columbia University. Her work focuses on developing data-driven approaches to better understand soil properties and dynamics with an emphasis on the role of soils in terrestrial carbon cycling.
Hancheng Guo is currently pursuing his Ph.D. at Zhejiang University and has joined Xia’s Lab as a visiting Ph.D. student. His research focuses on assessing the impacts of various agricultural management practices on soil carbon and nitrogen dynamics in China using process-based models.
Huixin Li received her bachelor's and master's degrees from Nanjing University, China, and is currently pursuing her Ph.D. at the University of Illinois Urbana-Champaign with Illinois Distinguished Fellowship support. She is co-advised by Dr. Xia and studies the mechanisms and modeling of carbon and nitrogen cycling in agroecosystems, with a current focus on refining the representation of particulate organic matter in process-based models.
We anticipate that one or two positions will be available for Fall 2026, similar to the 2025 position described here.
Master’s Students
Inesh Vytheswaran is a Statistics Masters student at Columbia and a graduate from Wesleyan University where he majored in Computer Science and minored in Physics. Currently, he is developing a machine learning model to quantify the uncertainty of organic carbon in soils across the U.S. agricultural lands. He is excited to explore the intersection of environmental and data science.
Research Assistants and Interns
Emely Mendez is from The Bronx, New York. She is a senior at Columbia University majoring in Environmental Science. She is passionate about understanding ecosystem dynamics and how conservation efforts can benefit urban and rural environments. She is currently a summer undergraduate research assistant in Xia's Lab focusing on designing strategic sampling plans and exploring relationships among ecosystem service outcomes.
Jordan Ashley is from Wayne, Pennsylvania. She is a senior majoring in Environmental Science within the Department of Earth and Environmental Science at Columbia University. She is completing her senior thesis in Xia’s Lab. Her thesis explores ways to improve agroecosystem datasets and indicators to better inform carbon markets and climate policy development in New York.
Victoria Woods is a senior in the Dual BA Program with Columbia University and Trinity College Dublin, majoring in Earth Science. She is passionate about sustainability and understanding human interaction with the environment. She is completing her senior thesis in Xia's lab, researching the factors that influence soil hydraulic properties and their implications for forest health and climate resilience.
Chris (Jongho) Yun: Chris is a senior at Bergen County Academies. He is interested in understanding the Earth’s mechanisms and their interactions by utilizing computational and statistical models. Currently, Chris is exploring the drivers of spatiotemporal dynamics of soil health using remote sensing signals and digital soil mapping tools. He is working on a dataset provided by the Stone Barns Center for Food & Agriculture.
Lab Alumni
Cailen Alice Tougher: Cailen conducted her senior thesis study in Xia’s Lab (2024-2025). Her thesis is titled “How Rotational grazing intensity affects long-term soil organic carbon”.
Danielle Kim: Danielle studied in Xia’s Lab (2024-2025) through the Bergen County Academies Senior Experience Program. She is currently a student at Cornell University.
Jake Cohen: Jake was an REU student in Xia’s lab (2025), where he explored environmental drivers of forest soil health. He is currently a student at the University of Toronto.
Tierna Oxenreider: Tierna was a research assistant in Xia’s Lab (2025), carrying out field and lab-based soil health tests. She is currently a Columbia University student.
Gary Leschinsky: Gary designed a project on modeling soil N2O fluxes from organic fields (2024-2025). He is currently a student at the Davidson Academy Online.
Margot Ann Grøtland: Margot was the lab manager in Xia’s Lab (2024-2025), conducting field, lab, and spectroscopy work. She is currently a Columbia University student.
