Spencer Koonin ’24



Project Title

What Controls the Biodiversity and Function of Cryptogam Microbiomes?

Certificate(s):  Environmental Studies

I studied plant life on a smaller scale by investigating mosses, liverworts, and lichens. Known as cryptogams, these small plants provide necessary macronutrients like nitrogen to their surroundings. We focused on a process known as biological nitrogen fixation, where nitrogen gas in the air around us is made available for organisms to use. I collected specimens of moss and lichen in the boreal forests of northern Québec and the Appalachian Mountains of North Carolina. These samples were selected in areas with varying levels of deposited nutrients and pollution from human activity. Back in the lab, I analyzed the samples to investigate how nitrogen and various metals influence biological nitrogen fixation activity and nitrogenase enzymes, with the goal of gaining a better understanding of the nitrogen cycle. This internship introduced me to the extraordinarily complex world of cryptogams, which our world could not exist without. My future can only benefit from the invaluable knowledge I gained, in particular the insight into how to create and address meaningful biogeochemical research questions about the world around me.

* This internship is connected to the HMEI Biodiversity Grand Challenges project, “What Controls the Biodiversity and Function of Cryptogram Microbiomes.”

Internship Year


Project Category

Climate and Environmental Science


Zhang Lab, Department of Geosciences, Princeton University - Highlands, North Carolina; Princeton, New Jersey; Sherbrooke, Québec, Canada


Xinning Zhang, Assistant Professor of Geosciences and the High Meadows Environmental Institute, Romain Darnajoux, Associate Research Scholar, Geosciences