In the rain forests of Borneo, it's nice to have ants in your plants.
In a mutually beneficial relationship, ants that make their homes in the hollow leaves of epiphytes generate carbon and nitrogen that nourish the plants.It took a young researcher from Salt Lake City to fathom the intricacies of the relationship between the tropical plants and their insect boarders. Kathleen Treseder, who graduated from the University of Utah this spring with a degree in biology, went to the Malaysian island of Borneo to assist in a U. research project dealing with re-forestation following logging.
But because she anticipated being "in the neighborhood," she also developed her own research project to study ants and epiphytes. These "air plants" don't root in the ground. They live on the surface of other jungle plants but don't use their hosts as a source of food. Over time, epiphytes develop roots inside their own leaves, feeding partly on the nutrients the ants introduce, if they are lucky enough to have an ant colony of their own. About three-quarters of those Treseder studied enjoyed such a sym-biotic relationship.
Ants carry organic debris inside the plants, and the debris releases nitrogen that the plants then absorb. The ants also exhale carbon dioxide that the plants use in the photosynthesis process, she found.
Her sojourn in the Borneo jungle was "the most amazing experience I've ever had," Treseder said. While she delved into the private lives of ants, she had to fend off such critters as leeches, ticks and other jungle dwellers.
"I wanted to know if I could survive in such an environment," she said. Survive she did. She even learned to pluck off the tenacious little leeches that go with jungle territory.
However, Borneo didn't provide her first experience in a jungle atmosphere. There is a minijungle on the top floor of the U. biology building, artificially created by heat and water. It's a humid, cloistery conglomeration of tropical plants that is central to the U.'s research program on the interactions between insects and plants in such a setting. Despite Utah's desert location, the program is a national center for such research.
Treseder learned the research techniques she used in Borneo from U. scientists, including Dinah Davidson and James Ehleringer, whose work is respected internationally. In particular, what she learned from Ehleringer (biology department chair) about using stable isotopes to learn the sources of plant nutrients was helpful as she studied epiphytes in Borneo's Bako National Park.
The student also credits the Hughes Undergraduate Research Program for piquing her interest in research. The U. program "gives incoming freshmen the opportunity to join a professor's research program. Mine was in Dr. Davidson's lab," she said.
Davidson also helped her write a grant request to the National Science Foundation to fund her independent research in Borneo. The NSF grant came from an undergraduate research fund as well, said Treseder.
Although she got down to the ant level in her Southeast Asian experience, her long-term interest is in preserving the world's rain forests.
"They are magnificent in themselves, with their diversity of insects, plants and animals. But they also may be a source some day for the cures for some diseases." As the demand for lumber from the forests increases, research into reforestation and preservation of the rain forest ecology will become more important, she said.
U. research indicates that the presence of ants in areas where trees have been harvested is important in keeping vines from taking over the deforested areas. These useful ants watch for enemy ants and kill any vine tip that touches their host plants, to prevent an invasion, Davidson found.
A report on Treseder's Borneo research has been submitted to the prestigious international journal "Nature." This fall, she will begin work on a master's degree at Stanford University.