Susan Cheng (U-M Ph.D. 2016) is a recipient of the ProQuest Distinguished Dissertation Honorable Mention Award for 2016. The award is given in recognition of the most exceptional scholarly work produced by doctoral students across a broad range of disciplines at the University of Michigan who completed their dissertations in 2016, according to the Rackham Graduate School.

Cheng’s thesis is titled: Shedding light on photosynthesis: The impacts of atmospheric conditions and plant canopy structure on ecosystem carbon uptake. She is currently a postdoctoral associate at Cornell University.

Cheng’s dissertation examined the role of light in controlling rates of photosynthesis in forests and croplands. By combining NASA satellite cloud data, ground-based light and ecosystem CO2 uptake measurements, and leaf photosynthesis measurements, Cheng found that clouds can decrease, and sometimes increase, CO2 uptake in forests and croplands by changing the amount and type of light available for plants to use. Cheng also found that the effect of clouds on ecosystem CO2 uptake is modified by the physical and ecological traits of plant canopies and how they change the distribution of light to individual leaves. Overall, this work identified how interactions between clouds and plant canopies affect how well forests and croplands can help slow climate change by removing CO2 from the atmosphere through photosynthesis. Cheng’s research also demonstrates the importance of using an interdisciplinary science framework to test assumptions about the interactions that organisms have with their environment. Cheng conducted her field research at the University of Michigan Biological Station.

Each year, Rackham invites faculty to nominate outstanding dissertations produced in their programs. The nominations are read and discussed by a faculty review panel who select finalists. Members of the Michigan Society of Fellows read the finalists’ dissertations, review the merits, and select the winners.

“It was both richly rewarding on a scientific level and personally satisfying to work with Susan Cheng during the course of her dissertation program here at the University of Michigan,” said Professor Knute Nadelhoffer, Cheng’s advisor. “Among other things, Susan leavened the intellectual bread of my lab, and likely of Professor Steiner's (her co-advisor in the College of Engineering) lab with her successful bridging of atmospheric and ecological sciences. Her creative and productive interdisciplinary work here at U-M has positioned her well for her current postdoctoral position at Cornell and should serve her well as she advances as a researcher and educator.”

ProQuest Information Services is the sponsor of the award program.