By Thomas Infante
Professor Janet Morrison’s collaborative research with students, titled “Nine Years in the Woods: Measuring and Mentoring in the Forests of New Jersey,” was showcased to an eager audience of students and faculty members at the Barbara Meyers Pelson ’59 Annual Lecture on Friday, April 6 in the Education Building Room 212.
Morrison was the inaugural recipient of the Barbara Meyers Pelson ’59 Chair in Faculty-Student Engagement, a three-year endowed position dedicated to collaborative work between faculty and students. As Pelson chair, Morrison helped students in the School of Science conduct extensive ecological fieldwork to study New Jersey’s various plant and animal species.
Morrison previously served as the chair of the Department of Biology at the College, a department that she has been a part of since 1997. She began the presentation by expressing gratitude for the opportunity to have additional resources and funding for student mentoring through her position.
“There’s at least two decades worth of very extensive research about the benefits of doing closely-mentored research with faculty members, particularly in the sciences,” Morrison said.
According to Morrison, science students benefit from the practical experience of doing lab work and field research, which reaffirms their confidence in their field of study.
“It helps to build what we call ‘science identity’ among our students,” Morrison said. “And we know that this is particularly important for students who come from underserved groups.”
Morrison went on to present statistics showing that this type of close mentoring had a positive correlation with students going on to achieve graduate degrees, both in the sciences as well as in other fields. She shared recent statistics of the College’s chemistry department, which showed that 20 percent of graduates go on to obtain a Ph.D. — a statistic that tops schools like Cornell, Harvard and Princeton.
As the Pelson Chair, Morrison integrated the faculty-student collaboration model into a large ecological project called “Deer x Invasives².” As the name implies, the project is centered on the white-tailed deer, commonly found throughout New Jersey. Deer are herbivores, but according to Morrison, they can be quite picky eaters.
“They have plants that they prefer and plants that they don’t prefer, and that changes over time as the plant tissues change,” Morrison said. “So something that’s preferred earlier in the spring might not be preferred in the fall.”
Other factors, such as abundance and availability, also contribute to the deer’s food preferences. These preferences have tremendous impact on the surrounding plant community, according to Morrison.
This effect has been compounded by the increase in the nationwide deer population in recent years, which Morrison described as “extraordinary.”
“In the most recent survey of Hopewell Township, there were 32 deer per square kilometer,” Morrison said as the crowd murmured in disbelief.
The massive deer population has made it easier to observe the animals’ effects on various types of invasive plants, the other focus of the project. Invasive plants like the mile-a-minute weed are nonnative species, and spread rapidly among a new habitat.
“They often can have detrimental effects on the native plant community that’s there, and we’re worried about that because we care about biodiversity and ecosystem function,” Morrison said.
Morrison explained that traditional experiments of nonnative plant species focused on a single type of invasive plant. However, this model is not viable in the modern suburban sprawl of New Jersey, where individual ecosystems are much smaller, and often home to a variety of invasive plant species.
“There’s a lot of urban/suburban infrastructure, but embedded in that is all this green stuff,” Morrison said, pointing at a topographical state map. “This is what nature looks like in the 21st century … in New Jersey, two-thirds of the land is the built infrastructure. So if we’re not paying attention to the natural areas embedded in that, we’re not paying attention to a lot of the nature.”
The preliminary stages of the project began back in 2008, when Morrison and her students started collecting data on local forests, eventually setting up six 4×4 meter study plots. By 2010, they were collecting data on the forests’ respective deer populations, including density and browse rates.
The project took off after receiving a grant from the National Science Foundation, and 20 students have since completed capstone papers on work related to their experiments. The main findings concerned the nonnative invasive plants such as Japanese stiltgrass. The findings showed that deer overbrowsing has facilitated the invasion of Japanese stiltgrass in areas with dense deer populations.
Morrison’s findings also showed that deer consume nonnative invasive plants equally as much as they do native plant species, showing a somewhat symbiotic relationship between the overpopulated deer and invasive plants.
“This could mean that if we go in and try to control the deer herd, which a lot of agencies are trying to do, we could have a population explosion of nonnative plants that are being browsed at a high rate,” Morrison said.
Morrison structured her students into small groups, typically led by a senior or junior. She worked directly with the students involved with the project for course credit, who would oversee freshmen shadowing the experiments.
She then gave the floor to her students, who shared some of the work they have done with Morrison in the last few years. Alumna Gio Tomat-Kelly (’15), graduated with a degree in biology and is currently pursuing her Ph.D. at the University of Florida. She studied the process of nitrogen recycling in soil, and how nutrients introduced from invasive plants could potentially affect the native soil’s natural processes.
Alumnus Mitch Vaughn (’16) graduated with a degree in biology before obtaining his master’s the next year to become a high school science teacher. His research focused on the geographic origin of different species, and the effects on these origins in their interactions. He tested this by attempting to feed plant species of varying national origins to European slugs. Besides lettuce, the control plant, the slugs would only tolerate the European plant garlic mustard, showing a correlation of geographic origin.
Alumna Jen Wells (’16) graduated with a degree in biology and now works at the New Jersey Nature Conservancy. Her research focused on whether or not one invasive plant species would hinder another’s ability to invade the same area. By planting garlic mustard and Japanese stilt grass in a greenhouse one after the other and measuring the biomass of the soil, it was found that the original plant had a suppressing effect on the second’s ability to grow.
Olivia Sohn, a senior biology major, focused her research on the hypothesis that thorn-bearing plants will instinctively learn to grow more thorns after a significant deer browsing period. By measuring the thorn-to-stem ratio of Rosa multiflora plants, it was found that the plant does grow more protective thorns in the presence of deer.
Based on the testimonies of her students, Morrison’s mentorship has led them to make discoveries not only in the sciences, but about themselves as well.
“Without her, I never would have thought that I myself could pursue a graduate degree in research,” Kelly said. “And research is really important because without research there’s no understanding, and without understanding, we can’t have progress.”