The Rainforest Microbiome: Exploring Symbiosis Between Trees and Microbes
By Madeline Glaser, Marine biology ‘27
Students collect data at a research site in the Olympic Rainforest (Image Credit: Sharon Doty).
At the La Selva Research Station, deep in the tropical rainforests of Costa Rica, life moves fast. In the early hours of the morning, howler monkeys call out to each other from tree to tree, while rainbow-billed toucans dip gracefully through the air. Along the forest floor, hard-working leafcutter ants march in single file lines with no discernible beginning or end. At night, the sky lights up with stars, and the forest with the trills of poison dart frogs and the chirps of crickets the size of your palms. Each of these organisms, though wildly different, has adapted unique ways to survive in this ultra-competitive environment.
This world of biodiversity doesn’t end with the organisms you can see. Billions of microscopic bacteria and fungi lay the foundation of some of the most important processes in the entire rainforest ecosystem. Despite their ecological importance, very little is known about these microorganisms, including the distribution of species across different ecosystems and the roles they play in nutrient uptake.
To explore some of these questions, Professor Sharon Doty and Dr. Robert Tournay led a UW study abroad program called “The Rainforest Microbiome: Comparing Tropical and Temperate Ecosystems.” Last summer, 18 other undergraduate students and I participated in the program, along with our two graduate teaching assistants. We began our work in Costa Rica, where we spent two weeks exploring rainforest diversity and digging up root samples to be processed in-lab. We then spent about a week at the UW Olympic Natural Resources Center in Forks, WA, where we took more plant samples and surveyed sites for future collection.
During the program, we focused on endophytes–organisms that live inside of plants. Specifically, we were interested in bacteria that fix nitrogen, turning atmospheric nitrogen into a form that can be absorbed by plants. By forming a symbiotic relationship with these nitrogen-fixing endophytes, plants can increase their chances of survival. Research on this complex process has the potential to help scientists fight plant diseases, improve sustainable farming practices, and reduce agricultural reliance on chemical fertilizers.
Over the course of the program, we gained hands-on experience with specific microbiology practices, but were also encouraged to develop our own observations and scientific questions in our field notebooks. I grew an interest in the diversity of butterflies and moths, observing the ways they flew and the shapes of their wings. Prior to the program, I didn’t have much experience in microbiology, but the teaching team’s knowledge and passion made it easy to learn quickly. My time digging up root samples, avoiding bullet ants, marveling at macaws, and learning about the rainforest microbiome are treasured memories that I will carry with me into my future as a scientist.