Environmental Internship Program - 2023 Booklet

Helen Brush ’24
ECOLOGY AND EVOLUTIONARY BIOLOGY
Certificate: Applied and Computational
Mathematics
PROJECT TITLE
Mechanisms of
Shrubification in a
Changing Arctic
ORGANIZATION(S)
Levine Lab,
Department of Ecology
and Evolutionary Biology,
Princeton University
LOCATION(S)
Toolik Field Station,
Fairbanks, Alaska
MENTOR(S)
Jonathan Levine,
J.N. Allison Professor in
Environmental Studies,
Professor of Ecology and
Evolutionary Biology;
Ruby An, Ph.D. candidate,
Ecology and Evolutionary
Biology
I worked at the Toolik Field Station in the
Alaskan Arctic to investigate the mechanisms
driving increased shrub presence, or
“shrubification,” in the Arctic tundra. This
widely observed Arctic phenomenon can
have local and large-scale consequences.
Understanding the environmental drivers
of shrubification is important for predicting
the trajectory of this ecosystem under future
climate scenarios as the Arctic rapidly warms. I
helped to establish a manipulation experiment
subjecting nearly 1,000 individual shrubs
across 80 experimental plots to combinations
of warming, lengthened growing season,
and nutrient addition. In these plots, we
conducted extensive phenological and physical
measurements of the shrubs and surrounding
soils and plant communities to track treatment
effects. As this was my second summer working
at Toolik, I practiced greater independence and
contributed more meaningfully to conversations
about experimental design and data analysis.
Outside of the shrub experiment, I engaged
with other members of the Toolik community,
learning about their research and helping when
they needed extra hands in the field. I gained a
heightened appreciation for interdisciplinary
work as we took approaches from multiple fields,
including community ecology, soil chemistry,
and mathematical modeling. Spending the
summer in such awe-inspiring wilderness with
wonderful people was a privilege that I’m very
grateful for.
CLIMATE AND
ENVIRONMENTAL SCIENCE
23