Over the past 4 decades, nitrogen exports have increased, while carbon exports have been dependent on precipitation in the Kuparuk River

Contributed by: Arial Shogren @DrArialShogren

 

Keywords

Aquatic, Biogeochemistry: C, Biogeochemistry: N, Climate change, Conservation, Ecology, Ecosystem ecology, Environmental change, Field, Freshwater, Fundamental research, North America, Observational, Tundra, Under-represented minority

 

Slides

Note: click the gear symbol to see notes that accompany the presentation

View and download in google slides here

 

Resources

Arial Shogren, J. P. Zarnetske, B. W. Abbott, F. Iannucci, A. Medvedeff, S. Cairns, M. J. Duda, W. B. Bowden. 2021. Arctic concentration–discharge relationships for dissolved organic carbon and nitrate vary with landscape and season. Limnology and Oceanography 66(S1): S197-S215. Find article here.

 

Data Nugget Activity: http://datanuggets.org/2019/11/streams-as-sensors/

 

Notes

Slide 1: Researcher’s Background

Arial is a stream ecosystem ecologist – she likes to follow water around! Her research captures how water moves and transforms natural and anthropogenic material as it flows across ecosystem boundaries.

PB: Why did you become a biologist?
AS: I always loved being and working outside, and always knew I wanted to have a career in some type of environmental science. I chose aquatic ecology because I had a great experience as an undergraduate research technician in a lab that studied stream biogeochemistry. That experience inspired me to go to graduate school for aquatic ecology.

PB: What is your favorite part about your job?
AS: Science is actually a very creative process, so that’s a really fun part of my job. I also love working with students and other researchers and doing team science.

PB: What obstacles have you overcome to get where you are?
AS: I have always loved water & science, but I was often the only minority in the room & didn’t see other people that looked like me doing science. My undergrad mentors encouraged me to apply to attend the Society for Freshwater Science conference in 2013 as an Instar Fellow. The SFS Instars program is designed to help students from underrepresented groups feel welcomed and supported at their first scientific meeting. Participating in Instars was the first time I got a better vision of how diverse & welcoming science could be!

PB: What advice do you have for aspiring biologists?
AS: Always try to have an open mindset: even if you decide a specific field of science isn’t your jam, if your goal is to be a lifelong learner then all perspectives and experiences are important and valid.

PB: Do you feel that any dimension of your identity is invisible or under-represented/marginalized in STEM?
AS: Yes

PB: Can you elaborate on your answer above?
AS: I’m daughter of an immigrant (mom from Colombia), the first person in my family to pursue a PhD / career in science, and also part of a dual career couple (my partner is also in academia).

 

Slide 2: Research Overview

Take home message of study

Arial and her colleagues use sensors to measure the concentrations of carbon and nutrients like nitrogen coming from rivers that drain different landscapes. Long-term data have been collected from these sites, allowing Arial to examine how these ecosystems are changing over time. Arial and her colleagues take the “pulse” of each ecosystem and connect changes to precipitation events. The main “take-home” message is that nitrogen exports are increasing, but carbon exports are dependent on precipitation. Intense rain events quickly add dissolved organic matter and carbon into the stream.

Study system

Arial’s research has taken her to many streams and rivers – recently, she has been studying rivers that flow across Arctic Alaska. To study how Arctic ecosystems are changing, she deploys submersible water quality sensors that measure the integrated signal of carbon and nutrients moving across the landscape.

 

Slide 3: Key Research Points

Main figure

By measuring the concentrations of carbon and nutrients, like nitrogen, coming from rivers that drain different landscapes, Arial can take the “pulse” of each ecosystem. Long-term data from the Kuparuk River in Alaska show that nitrogen exports have been increasing over the past four decades (shown by the trendline). However, carbon exports are not showing the same upward trend through time. Years with high carbon exports are also years that had higher annual precipitation.

Societal Relevance

This is important because rain events are changing in the Arctic – it’s becoming wetter (more storms) for longer (a longer summer season). This means that as rainfall increases in intensity and duration, there is more opportunity for biologically-reactive species – like nitrogen – to enter into streams. This can stimulate growth on-site, or the nitrogen can be exported downstream.