With clear blue skies, Rahila Yilangai takes a summer selfie while doing fieldwork on a forested ridge, with a broad valley below and mountain skyline of Crested Butte Colorado

Published January 2024

Five questions & answers

Rahila Yilangai is a PhD student from Nigeria, who navigates her research with deep curiosity and a passion for ecohydrology. A PhD student in Geography, she is part of INSTAAR鈥檚 Ecohydrology Lab led by Holly Barnard.

Rahila won an INSTAAR DEI Summer Scholarship in 2023 and used it to support her investigations of the relationship between trees, water, and climate. We caught up with her to ask about her summer and get to know her and her work.

Questions & Answers

1. What is your main area of research?

My research is in ecohydrology. I鈥檓 working on the interaction between vegetation, climate, and hydrography. So, I鈥檓 looking at the interaction between trees and water at different topographical gradients, and also climate relationships.

What I do is first monitor transpiration in trees. Then I analyze tree cores to find the relationship between past climate events and growth and to look at the responses of tree growth to drought.

I鈥檓 also looking at plant-mediated hydrological distribution. The hydrological distribution is the passive lifting of water by plant roots to the surface of surrounding soil areas. I鈥檓 looking at whether failure in roots鈥 hydraulic conductance will cause limitations to this hydraulic redistribution process that plants mediate.

2. How did you become interested in ecohydrology?

Before I got admitted to CU, I was doing research monitoring transpiration in trees in riparian forests in Nigeria. I decided to do a PhD, and searched for professors in the U.S. who are working in that area. I came across Holly [Barnard] at INSTAAR, and I saw that her research was aligned. She was doing a similar thing to what I was doing.

During my master鈥檚 program in Nigeria, I worked on plant-animal interactions; but there was a professor from the U.S. who used to come and teach us. We wanted to do a project together in Nigeria, to sample plants鈥 diversity in the gallery forest in the reserve. Eventually she introduced me to ecohydrology. [This] was a completely new research area, that I wasn鈥檛 even aware of. It was real science for me! And I got so interested. I decided to switch completely from behavioral ecology to ecohydrology.

The next time we were going to apply for funding, we said, okay, let鈥檚 upscale from stomatal conductance to sapflow, put sensors on the trees and see what their transpiration responses are. So it was taking me deeper and deeper into ecohydrology. I discovered I was the first person in west Africa to buy the leaf porometer for measuring stomatal conductance from the USA, and plant sensors for measuring sap flow from the manufacturer in Australia.

There were no resources in Nigeria to train me. So I had to keep looking for help, mostly in the U.S. I contacted Professor Barnard for a PhD. I knew that if I didn鈥檛 come to this place, I would not get the training I want. So I decided to make contact, and we started making plans for a PhD.

3. You were an INSTAAR DEI Summer Scholar this past summer. What did you work on during that time?

I was so occupied during the summer. We went to the field. I learned how to install the sensors with my advisor. She taught me how to put the sensors on the different trees and how to connect them to the data logger. That was the first part of it.

Then I learned how to make the sensors in the lab from scratch.

After that I started working on my tree cores. The tree cores were already collected, but at that time I did the cross dating. I then marked the cores with colors for different years, and then then scanned and cut them into years鈥攁ll the rings鈥攃arefully cut them into samples and put them in vials. So most of the summer I was doing that. I had 81 cores.

It was a learning process for me, because I鈥檇 never handled tree cores before, I didn鈥檛 know how to scan and date the cores. So this was a very new area of learning for me. Weekdays were not enough for me鈥擨 would go to the lab on Saturdays and Sundays. I needed to finish cutting the cores before I resumed classes in the fall.

4. You recently participated in a 鈥淩everse Science Fair鈥 at Northglenn High School as part of a science communication course. What was that experience like?

My advisor sent us the advert for the science communication course and encouraged us to go if it fit in with our work. I decided it would help me present my work to a nonscientific audience, and I wanted to learn about that. So I joined the one-credit class.

It was during that class that we were invited to come to the science fair. I made a poster. You have to simplify your work, make sure there鈥檚 no jargon, and present your work to someone who is a nonscientist. You have to present it to high school students who don鈥檛 understand all that jargon.

It was really interesting, because I never knew I could simplify my work into plain language like that. I was very excited with the practice. That was the first time I made a poster presentation, and the first time I presented my work to high school students.

The students were very engaged and asked me questions and I could answer in plain language. There was a way I could say it in a way that everyone understands.

5. What do you like to do when you鈥檙e not doing science?

This is the end of my first year. Next year may give me a little bit of time to do some other things.

First, I am a bird watcher. I started making plans with some of my friends who also love watching birds to start after the winter. And then one of the things I want to do is learn how to swim. I鈥檒l probably register for a gym class or something. I have a lot of church engagements. That鈥檚 a significant part of my life.