About ​Me

I am a Postdoctoral Fellow in the Wolf lab at the department of Integrative Biology at the University of Texas at Austin. I completed my PhD under the supervision of Duncan Menge in the department of Ecology, Evolution & Environmental Biology at Columbia University. My research encompasses biogeochemistry, plant ecophysiology and the response of terrestrial ecosystems to global change. I am interested in patterns, trajectories and controls of the nitrogen and carbon cycles and their feedbacks with climate, with an emphasis on biological nitrogen fixation. In my research I use a range of approaches, from methods development, to experiments (greenhouse, growth chamber, field), to theoretical modeling, to terrestrial biosphere modeling, to analyses of forest inventory data.

News

September 2023:
​New paper out in Journal of Ecology! We showed that nitrogen-fixing trees have relatively high photosynthesis and water use efficiency because they can attain and sustain higher leaf nitrogen than non-fixers, not because of a difference in how photosynthesis and water use efficiency scale with leaf nitrogen in nitrogen fixers vs. non-fixers. Bytnerowicz et al. 2023
July 2023:
Sofia Bautista presented her research on drought tolerance of several herbaceous species in an experimental garden at Brackenridge Field Lab assessing relationships between global change, biodiversity, and ecosystem function. It was a pleasure to mentor Sofia as part of the InSTInCT REU program at UT Austin!
July 2023:
New paper out in Environmental Entomology! We observed high rates of N fixation in xylophagous beetle larvae at Black Rock Forest in New York and quantified how quickly insect N fixation rates decline under laboratory conditions. Our results suggest past studies may have systematically under-reported insect N fixation rates. This was led by Isobel Mifsud, and represents her MA work at E3B Columbia. Congrats, Isobel! Mifsud et al. 2023
February 2023:
I gave a talk at the CESM Land Model and Biogeochemistry Working Group meeting on our experimental work on the temperature sensitivity of nitrogen fixation and incorporating those results into land models.
December 2022:
New paper out in Ecological Monographs! Using a field fertilization experiment spanning temperate and tropical locations, we show that tree symbioses sustain nitrogen fixation under excess nitrogen supply. This finding refutes a previous hypothesis that temperate trees maintain similar fixation rates across soil nitrogen supply while tropical trees turn off fixation when soil nitrogen supply is sufficient. Menge, Wolf, et al. 2023.
October 2022:
I was invited to give a talk at the INCyTE 2022 Fall Symposium​, which was titled:
​"Temperature response of nitrogen fixation: A model intercomparison project incorporating physiological measurements into land models"
It was great to hear about all the cool science that INCyTE people are doing and to brainstorm about future collaborative projects!
August 2022:
The joint Ecological Society of America & Canadian Society for Ecology and Evolution meeting was a blast! I gave a talk on photosynthesis and water use efficiency in nitrogen-fixing and non-fixing trees from a field fertilization experiment, with Jen Funk, Duncan Menge, Steve Perakis, and Amy Wolf as coauthors. I was also an author on talks by Vanessa Lau on the temperature response of nitrogen fixation costs and by Ayanna Butler on how symbiotic bacteria and nitrogen availability affect water use efficiency in nitrogen fixers. 
August 2022:
​I had a wonderful time learning to run the Community Earth System Model at the 2022 CESM Tutorial! Thank you, NCAR!
July 2022:
Our Nature Plants paper received an honorable mention for the ESA Biogeosciences Section Elizabeth Sulzman Award (for an outstanding publication by a graduate student)! ​
June 2022:
Our Nature Plants paper received honorable mention for the ESA Early Career Ecologists Section Outstanding Publication Award!
June 2022:
I was interviewed for an article by Climate Feedback about claims related to climate change that promote alleged benefits of elevated carbon dioxide while downplaying its adverse effects on climate.
February 2022:
New paper out in Nature Plants! We measured the temperature sensitivity of nitrogen fixation across a range of growing temperatures in tropical and temperate tree species. Bytnerowicz et al. 2022.

See here for an associated News & Views piece published by Ying-Ping Wang and Ben Houlton in Nature Plants

See here for a news piece about our Nature Plants paper by UT Austin's College of Natural Sciences
August 2021:
New paper out in American Naturalist! We analyzed the US Forest Service Forest Inventory & Analysis database to show that bimodality in nitrogen fixing tree abundance is the norm in the United States; in both young and old forests. We then used theory to explore the mechanisms that could generate this pattern and the conditions under which these mechanisms may occur and be important. Bytnerowicz and Menge 2021.
July 2021:
I had a great time at Phys-Fest 3! There I learned lots of new techniques in plant eco-physiology at the beautiful Colorado State University's Mountain Campus. It was so wonderful making lots of new friends (can't wait 'til we see each other again!) and having fun doing things like taking a dip in an ice-cold creek in the mornings and hiking around the majestic Rockies. Thank you to all the organizers, instructors, and funders!
Photo credit: Claudio Guevara
July 2021:
New paper out in Biogeosciences! We developed a modified representation of symbiotic nitrogen fixation in the land component of NOAA's GFLD Earth System Model. Kou-Giesbrecht et al. 2021.
February 2021:
I am honored to have been selected as the recipient of the 2020 Don Jay Melnick Dissertation Award from the faculty at Columbia's E3B department, who have inspired me so much over the last few years. It is very meaningful to me that the award is in Don's memory. Don was my Thesis Development advisor and was incredibly supportive to my professional growth and my personal life. I am grateful to have known him and cherish the many conversations that we shared.
December 2020:
After a long delay due to COVID-19 (my private defense was in April), I finally gave my public exit talk at Columbia. It was E3B's first exit talk on Zoom and although I would have loved to have done it in person, it was great having friends, family, and collaborators tune in from all over the world!
November 2020:
I was honored to give my first invited department seminar (via Zoom, of course) at the department of Integrative Biology here at UT Austin!
November 2020:
Check out this Q&A that UT Austin's Biodiversity Center did about me and my research!
May 2020:
I'm delighted to announce that this summer I will be joining the Wolf and Farrior labs at the University of Texas at Austin as a Stengl-Wyer Postdoctoral Scholar.
April 2020:
I'm a doctor! Yippee! Thank you to everyone that supported me along the way, particularly my family, my advisor, and my committee.
Also, huge shout out to E3B for the bubblies!
December 2019:
I had a poster and was a coauthor on Duncan Menge's talk at AGU in San Francisco. Both were in the "Carbon and Nutrient Cycle Interactions in the "Terrestrial Ecosystems: Integrating Theory, Observations, Experiments, and Models" session - thank you to the INCyTE folks for organizing! My poster was on how temperature and species affect the timescales over which nitrogen fixation is regulated, with Kevin Griffin and Duncan Menge as coauthors. Duncan's talk was on the structural and metabolic costs of nitrogen fixation, with Amelia Wolf and Kevin Griffin as additional coauthors.
​December 2019:
I'll be spending the next few months in Southern California as a visiting student researcher in Pete Homyak's lab at UC Riverside. Looking forward to the warm weather and interacting with Pete and his fantastic group while I am here!
June 2019:
​I enjoyed visiting Oregon's Coast Range, where I measured photosynthesis and dark respiration on red alder and Douglas fir. These data will tell us something about how leaf (or needle) carbon exchange changes with added nitrogen and phosphorus and how this may be different for nitrogen fixing vs. nonfixing trees. Thank you to Steve Perakis for showing me around the site and for providing support while I was there.

​May 2019:
I gave a CRPPY talk at Princeton on the timescales over which nitrogen fixation is regulated in tropical and temperate woody plants. It was great seeing old friends, meeting new ones, and hearing about the exciting research happening in the EEB departments at Columbia, Rutgers, Princeton, Penn, and Yale.
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​April 2019:
New paper out in Methods in Ecology and Evolution that develops a method for making coupled measurements of nitrogenase activity and carbon exchange in nitrogen fixing plants that are continuous, repeatable and in real-time. Bytnerowicz et al. 2019.

​December 2018:
I had a great time at my first AGU meeting in Washington DC! There I gave a talk in the session "From -omics to the Earth System: Bridging Scales to Improve our Understanding of Earth System Function and Response I" with Kevin Griffin and Duncan Menge as coauthors.