2012


Nathan Mathabane

Nathan Mathabane


Years participated in RESESS:
2012


An Overview

Major: Geosciences
Academic Affiliation: Princeton University
Research Mentor: Jason Neff, CU
Computer Mentor: Daniel Fernandez, CU
Graduate Student Mentor: Kathy Kelsey, CU
Writing Mentor: Lon Abbott, CU


Biography

Nathan grew up in North Carolina and Portland, Oregon. His father grew up in a slum of Johannesburg under the Apartheid system in South Africa and his mother is from the States. They meet in New York City at Columbia Journalism school, a program out of which his father subsequently dropped to write Kaffir Boy, his first book and a national bestseller. He and his two siblings are close, all attending or graduating from Princeton University. Nathan first became interested in geology after taking an introductory course during his sophomore year in college, noting that, "The professor, a structural geologist by specialization, had a wonderful way of introducing the geosciences that was both incredibly informative and accessible." When not studying, he runs as a member of the cross-country and track and field teams and is the associate opinion editor at Princeton. He enjoys being outdoors experiencing new things and seeing new sights.


Abstract

Carbon stocks and sequestration in forests: How much do we know?

As anthropogenic CO2 emissions in America increase, both Washington D.C. and state governments look for ways to offset those carbon increases. Our forests provide an opportunity for carbon sequestration, assuming well-informed and deliberate management practices. Accurate spatial and temporal estimates of carbon stocks are integral to developing wise management practices. Spatial carbon stock estimates are often represented in carbon maps, while temporal estimates are calculated using computer models. These maps and models come from a variety of sources, such as the United States Department of Agriculture (USDA), the Forest Service (FS), and independent researchers. Here we evaluate the Forest Service’s Forest Vegetation Simulator (FVS) to determine its sensitivity to input changes as well as its predictive ability over time. We analyze field data collected from a site in the San Juan National Forest. This site was clearcut in 1920, allowing us to model a complete regrowth over 90 years. Using biomass-to-carbon equations, we compare present-day carbon storage to FVS model projections. Finally, we look at the Forest Inventory and Analysis (FIA) database and a spatial carbon map developed by researchers at the University of Colorado to assess the validity of landscape-scale estimates. Results indicate that the four spatial carbon estimates we use vary by only 25%, while the temporal carbon estimates diverge radically from field data. Knowledge of carbon uptake rates is one of the most pressing questions in atmospheric and ecological science. It is imperative that carbon models be improved to achieve this goal. Spatial and temporal comparisons such as the one conducted here are needed to provide the groundwork for model development.