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 supporting 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.

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.

Kira Wiesinger is from Bellevue, Washington. She is a Climate Science Masters student at Columbia and a graduate from the University of California, Berkeley, where she majored in Molecular Environmental Biology and minored in Data Science. She previously worked at the US Environmental Protection Agency in San Francisco. She is currently a research assistant in Xia’s Lab where she is focused on soil carbon dynamics and developing digital soil mapping models.

Sitian Xia is from Beijing, China. She is currently pursuing her bachelor’s degree at Barnard College, Columbia University. She is interested in using applied mathematics, data analysis, and computational modeling to better understand and address environmental challenges in soil and agricultural systems. In Xia’s Lab, she supports research related to the Farm-MIP project and data-driven soil systems modeling.

Maisha Tasmi is from northern Virginia and is an undergraduate student majoring in Environmental Science with a minor in Economics at Barnard College. She is interested in soil health, regenerative agriculture, and using data to better understand environmental systems. She supports research related to local soil health projects in collaboration with NGOs.  

Research Assistants and Interns

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 modeled soil N2O fluxes from organic fields as a high school intern in Xia’s lab (2024-2025). He will be an incoming student at Stanford University.

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.

Emely Mendez worked as a undergraduate research assistant and did her thesis in exploring the relationships between soil health and other ecosystem outcomes (2025-2026).

Jordan Ashley did her senior thesis exploring ways to improve datasets and indicators to better inform carbon markets and climate policy development in New York (2025-2026).

Victoria Woods did her senior thesis in researching the factors that influence soil hydraulic properties (2025-2026). She will be a graduate student at the University of Cambridge.

Elizabeth Huggins did her senior thesis in standardizing and integrating measurements of carbon storage and ecosystem fluxes to investigate rangeland carbon dynamics (2025-2026).

Chris (Jongho) Yun: Chris studied in Xia’s Lab (2025-2026) through the Bergen County Academies Senior Experience Program. He will be an incoming student at Cornell University.

Konaneakamahina Morikawa did her senior thesis in a meta-analysis of water aggregate stability (2025-2026).

Bella Guo: Bella studied in Xia’s Lab (2025-2026) through the Bergen County Academies Senior Experience Program. She will be an incoming student at Carnegie Mellon University.