Skip Navigation
Faculty | Courses | Giving
The E3B department is delighted to announce that Dr. Sian Kou-Giesbrecht has won the 2021 Don Jay Melnick Award!
Named in honor of one of the founders of our department, the Melnick Award recognizes outstanding dissertation work and other departmental activities. Using an uncommonly wide array of techniques, Sian’s thesis overturned a long-held belief. Prior to her work, nitrogen-fixing trees were thought to be a boon to climate mitigation. The idea was that their rapid growth and ability to fertilize the surrounding soil led to greater carbon storage in plants. In her first chapter, an elegant bit of mathematical theory, Sian showed that another consequence of nitrogen fixation – emissions of nitrous oxide (a powerful greenhouse gas) from the soil – could counteract the carbon storage effect. Her theory predicted that nitrogen-fixing trees could actually be worse for climate (compared to non-fixing trees), and under what conditions. Sian’s second chapter used a meta-analysis to show that the nitrous oxide effect predicted by her theory was borne out across a wide range of sites. Her third chapter combined painstaking, rigorous experimental fieldwork, lab work, statistical modeling, and an extended theoretical model to show that her theoretical predictions were correct in Black Rock Forest. These three chapters have changed the way we think about nitrogen-fixing trees and climate. Sian’s fourth chapter developed, tested, and validated a new version of the nitrogen cycle in the land model of NOAA’s earth system/climate model. This herculean effort will pay off for decades, given the centrality of NOAA’s model for climate science and policy.
In addition to her outstanding research, Sian was a phenomenal teacher, an excellent departmental citizen, and a strong voice for diversity. She is now revamping the nitrogen cycle in another earth system model as a postdoc at the Canadian Centre for Climate Modeling and Analysis.
Congratulations Sian!

Columbia has announced the creation of the Columbia Climate School, with E3B Professor Ruth DeFries named as Co-Founding Dean.

Ruth will remain a University Professor and Denning Family Professor of Sustainable Development in E3B, as well as continue to play an integral role in the Undergraduate Program in Sustainable Development at Columbia’s Earth Institute. Her world-renowned scholarship is committed to understanding the changes experienced by the planet over the course of human existence. She is also a public advocate whose dogged commitment has resulted in advances around the world concerning climate change, food insecurity, and nature conservation. And, importantly, she has been instrumental in the creation of several innovative Earth Institute programs.

Please see more about this announcement HERE!

Professor Deren Eaton wins NSF Career Award

Deren Eaton, Ph.D., assistant professor of Ecology, Evolution, and Environmental Biology, has been awarded the National Science Foundation’s (NSF) prestigious Faculty Early Career Development (CAREER) award, the NSF’s highest honor awarded to early career faculty. The five-year $956K grant will support his proposal “Linking Phylogenetic Inference at Genome-wide and Local Genealogical Scales”. 

Eaton’s research combines computational genomics and bioinformatics with field-based studies of diverse and hybridizing plant species to examine the evolutionary consequences of hybridization in shaping the history of plant diversification. With the NSF grant, Eaton’s lab will produce new genomic data sets, and develop new software tools, to better understand how variation within and among genomes is affected by historical hybridization. 

“The size, complexity and variation among plant genomes presents a major challenge for comparative genomics, for which most tools have been designed to examine variation in human genomes, which are really not that variable,” says Eaton, who is also an affiliate member of Columbia’s Data Science Institute. “Now that we can more easily assemble complete plant genomes, we can begin to investigate evolutionary relationships not only among populations and species, but also in terms of how such patterns vary across regions of their genomes. The extent and speed with which plant genomes rearrange affects patterns of genetic linkage, which in turn can bias many phylogenetic inference methods. By developing new methods that accommodate variable genome structure and linkage we can establish better null hypotheses against which to detect interesting patterns, such as genomic signatures of hybridization.”

Eaton’s project will produce new software tools for inferring the evolutionary history of organisms from genomic data, as well as new didactic tools that will form the basis of a new course at Columbia focused on phylogenetic algorithms and methods. This research fits into a broader theme of Eaton’s lab towards understanding the drivers of diversification in global hotspots of plant diversity. “A major outcome of this research will be an improved understanding of the extent of hybridization across the tree of life, which is fundamental to our understanding of biodiversity and evolution, but also has important implications for conservation”, says Eaton. His lab will apply their new methods to investigate gene flow among endemic plant species in alpine regions of the Tibetan plateau that have historically been highly isolated, but now come into contact as a result of human development, land-use transformation, and climate change.

Click HERE for more information.

The E3B department is delighted to announce that Dr. Thomas Bytnerowicz has won the 2020 Don Jay Melnick Award!
Named in honor of one of the founders of our department, the Melnick Award recognizes outstanding dissertation work and other departmental activities. Tom’s entire dissertation is incredibly elegant and rigorous. His first chapter developed a new method for measuring nitrogen fixation, which has opened new doors for an entire field, and set the stage for his second and third chapters. His second chapter overturns a decade-long assumption about the temperature response of nitrogen fixation, changing both our fundamental understanding and how people model nitrogen fixation. His third chapter provides the first answer to the question “how long does it take for nitrogen fixation to turn on or off?” and simultaneously provides an explanation for why some soils become very nitrogen rich. His fourth chapter made the novel observation that the successional distribution of nitrogen-fixing trees is bimodal, and provided an elegant theoretical explanation for the observation. He accomplished this groundbreaking work while raising two great kids, and was awarded with a prestigious postdoc fellowship from UT Austin.
Congratulations Tom!

Fall fieldwork in Black Rock Forest! 

Aria Pereira (left), Sian Kou-Giesbrecht (middle), and Palani Akana (right) celebrated a successful harvest of the rooting system of a Robinia pseudoacacia tree sapling.

The harvest was the end of the Menge lab‘s NSF-funded experiment, for which the Black Rock staff were instrumental.


Congratulations to the Cords lab!

Members of the Cords lab swept the poster awards at Northeastern Evolutionary Primatology meetings on November 8th and 9th.

Rachel Donabedian (center) won first prize, and Holly Fuong (left) and Amanda Johnston (right) tied for second.

The Tick App - YT Vid

E3B Professor Maria Diuk-Wasser and Postdoctoral Research Scientist Pilar Fernandez discuss fighting ticks with a tap of your phone.

The Tick App, created by Diuk-Wasser, is a free app aimed at combatting Lyme disease. You can track when and how you are exposed to ticks, while Diuk-Wasser and her team learn more about tick activity to identify areas of high tick risk and help prevent exposure. Click HERE to watch them discuss their study!


Check out our E3Botanists! 

PhD student Patrick McKenzie and MA student Jared Meek spent their summer doing fieldwork in the Hengduan Mountains of China and Tibet for Professor Deren Eaton‘s lab.

10 day old House Sparrow-cropped

Our PhD student Stefanie Siller is out in Fargo, ND working on the impacts of intergenerational stress on house sparrows.

First, they color the house sparrow chicks to keep track of them in their nest. They then take measurements of the birds until they are 10 days old (as pictured above), the age at which they begin to fledge. Finally, they band them and hope the birds come back as adults!


Congratulations to E3B PhD students Pooja Choksi, Sarika Khanwilkar, and Vijay Ramesh who received an Early Career Grant from National Geographic Society’s Committee for Research and Exploration for ‘Project Dhvani: Eavesdropping on Biodiversity for Ecological and Social Benefits’!

This grant will aid the Project Dhvani team to carry out fieldwork in central India during 2019 and 2020.

To find out more about Project Dhvani (Dhvani is the Sanskrit word for sound) and to stay updated on their work, click here!


Our PhD students Vijay Ramesh, Pooja Choksi, and Sarika Khanwilkar have received a grant from Advanced Consortium on Cooperation, Conflict, and Complexity (AC4) for Project Dhvani

The emerging technology of acoustics is opening a new window into capturing the diversity of sounds from insects, amphibians, birds, and mammals. Low-cost and time-efficient acoustic technology offers novel possibilities for a wide audience to appreciate biodiversity and for local resource managers to identify where and when diversity is under threat across areas of human-wildlife conflict. ‘Project Dhvani’ will use non-invasive audio recorders across a landscape of remarkable stronghold of biodiversity in India: the dry tropical forests of central India. This project will aim to understand how biodiversity varies across human-dominated land cover types in central India using sounds.

Project Dhvani is a collaborative undertaking of three young scientists, local non-governmental and academic institutions and the state Forest Departments in India. This team consists of Vijay Ramesh, who examines the effects of land-use and climate change on biodiversity; Pooja Choksi, who studies patterns of forest degradation and co-existence and Sarika Khanwilkar, who quantifies the relationships and feedback between people and the environment. You can learn more about the project at

Return to Top