Soil Carbon: From Nano- to Global Scales

2018 Faculty Research Award

Award Period: 2018-2020

Figure 1. Proposed microfluidic experiments: (a) Schematic view of the proposed microfluidic model of an idealized soil, and (b) time series of biofilm buildup in a microfluidic, soil-like porous material made from transparent Nafion granules (outlined by red dashed lines). Green indicates P. aeruginosa cells constitutively expressing green fluorescent protein (Drescher et al., 2013).

The amount of carbon trapped in soil is nearly as large as carbon levels in the atmosphere, biosphere and surface ocean combined. Despite its huge potential impact on climate change, soil carbon remains poorly understood. This project will explore the mechanisms that govern the storage and release of soil carbon, specifically the influences of mineralogy, hydrology and temperature. It is led by Ian Bourg, assistant professor of civil and environmental engineering and the Princeton Environmental Institute; Amilcare Porporato, the Thomas J. Wu ’94 Professor of Civil and Environmental Engineering, professor of civil and environmental engineering and the Princeton Environmental Institute; and Howard Stone, Donald R. Dixon ’69 and Elizabeth W. Dixon Professor of Mechanical and Aerospace Engineering. Bourg, Porporato and Stone will examine the impact of hydrological and mineralogical variables using an idealized soil model, or a “soil on a chip.” Then they will combine those data with nanoscale information of organic-carbon adsorption on mineral surfaces in order to understand transport and preservation processes at ecological scales. Their aim is to test fundamental assumptions of soil-carbon respiration in order to lay the groundwork for more accurate climate models and carbon-mitigation strategies.

Educational Impacts

The project includes a significant focus on mentoring and training undergraduate students, including two senior-thesis students and two PEI Summer Interns working with two or more of the researchers. Students will be invited to present their research at a major conference, such as the American Geophysical Union annual meeting, or to the Soil Science Society of America. Four undergraduates will be working on aspects of this research in University laboratories during summer 2018.

The results of the project will enhance the lecture materials on the topic of soil carbon in the undergraduate course taught by Bourg, “Introduction to Environmental Engineering,” and the graduate course taught by Porporato, “Ecohydrology.” The research also will provide new examples for Stone’s undergraduate differential equations course, “Mathematics in Engineering I,” and graduate fluid mechanics course, “Advanced Topics in Fluid Mechanics I.

Participating Department


Participants

Assistant Professor of Civil and Environmental Engineering and the Princeton Environmental Institute
the Thomas J. Wu ’94 Professor of Civil and Environmental Engineering, Professor of Civil and Environmental Engineering and the Princeton Environmental Institute
Donald R. Dixon '69 and Elizabeth W. Dixon Professor of Mechanical and Aerospace Engineering and department chair