Dept of Ecology Evolution and Environmental Biology - E3B

09/14/2023

01/31/2023

Acoustic recorders detected promising changes in the soundscape after a restoration project in India.

12/08/2022

Most species are not receiving protection until their populations are precariously small, thus dimming their prospects of recovery.

12/08/2022

Raccoons, coyotes, possums and other wild mammals are becoming more common in the country's most densely populated city. New research aims to map their populations and habits in hopes of decreasing conflicts with humans.

08/22/2022

WCS Ocean Giants team with our E3B Columbia graduate students Maria Papadopoulos and Anabel Carter in action, studying whales in the New York Bight! 🐋

05/06/2022

The E3B department is delighted to announce that Dr. Alexandra Huddell has won the 2022 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.

Alex’s dissertation focused on how agricultural frontiers, as she calls them, influence losses of nitrogen. Conventional agricultural practices in Europe, North America, and Asia lead to large nitrogen losses that cause dead zones, smog, and greenhouse warming. Agriculture is expanding along climate frontiers, occupying vast regions of the tropics that previously had little large-scale agriculture, and along management frontiers, with new crops and techniques). Do these frontiers exacerbate nitrogen leaks or mitigate them? When Alex started her Ph.D., this was a wide open question.

Alex first addressed climate frontiers, studying nitrogen losses in tropical agroecosystems and comparing them to the better studied temperate regions. She studied field systems in Mato Grosso, Brazil, where agriculture is expanding more rapidly than anywhere on earth. Her first chapter (AGE 2021) found that excess fertilizer in these agroecosystems leads to among the highest emissions ever recorded of nitric oxide (which forms smog).

Alex's collaborators in Brazil had previously found that huge amounts of nitrate (which causes dead zones) accumulate deep in the soil rather than leaking out into waterways. Alex's second chapter (Ecosystems 2022) tested an explanation for this high nitrate storage. She found that negatively charged ions (anions, like nitrate) stuck tightly to the soils in Mato Grosso, unlike the common situation in temperate soils (which tend to stick to cations instead of anions). This "anion exchange capacity" combined with the great depth of the soils (over 8 meters (!)) meant that the soils in Mato Grosso could continue to store nitrate at current levels of fertilization for hundreds of years.

This nitrate storage in Mato Grosso was intriguing. Was it ubiquitous in tropical agroecosystems? In her third chapter (a meta-analysis; Global Change Biology 2020), Alex found that it was not. She found that tropical agroecosystems leak as much nitrate as temperate ecosystems for a given level of fertilizer. However, she found that tropical agroecosystems emit substantially more nitric oxide than their temperate counterparts, as she had observed in Mato Grosso.

Alex’s fourth chapter (currently in review) focused on a management frontier. She is fascinated by the prospects of perennial grains (e.g., wheat that lives for more than one year), which are a hot topic in agroecology. Perennial grains are hypothesized to mitigate nitrogen losses compared with conventional agriculture, yet this hypothesis has rarely been tested. Alex worked at the SAFE experiment at the Lönnstorp Research Station, which grows perennial wheat alongside annual wheat. After a huge amount of painstaking, rigorous work, not to mention a new baby, she found that her hypothesis was spot on: perennial wheat soaks up way more nitrogen than annual wheat (~100 fold more), essentially preventing nitrogen losses.

Alex’s work is cutting-edge biogeochemistry. Fittingly, given the namesake of this award, her work matters for people and has clear management implications. Alex funded her work through an NSF GRF and an astounding 8 research grants, some of which were among the largest student grants there are. Immediately after graduating she began a postdoc at EPA, then quickly moved to a new position as a “Faculty Assistant” at the University of Maryland. In addition to her outstanding academic success, Alex was an excellent departmental citizen. She was deeply involved in DEI efforts, culminating in co-founding the Environmental Justice and Urban Ecology Summer Research Program.

Congratulations Alex!

06/08/2021

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!

04/16/2021

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.

03/24/2021

The Diuk-Wasser Lab is looking to hire a part time lab technician for molecular and field work on tick-borne disease pathogens!

Check out the job posting here, and apply through this link (not on Facebook): https://opportunities.columbia.edu/en-us/job/513430/lab-technician

02/23/2021

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!

02/07/2020

Blue Eared Kingfisher