On-Campus Nature Walk Identifies Invasive Species

By Connect Mason Reporter Nick Walker

“When you identify plants, it helps to use all of your senses. If you can touch it, touch it. If you can smell it, smell it. If you can taste it, that's even better,” said Andrea Weeks, professor in the environmental science & policy department during a campus-wide plant walk on Tuesday, April 22.

A group of fourteen students and faculty attended the walk, which covered the riparian buffer behind the student apartments, the area adjacent to the Mason Pond and an edge habitat along Patriot Circle.

As part of a series of Earth Week events, Professor Weeks began the walk with an explanation of Mason's local ecology.

Located on the Piedmont plateau, Virginia provides a hot spot of rarity and richness among plants. The Fairfax Campus was originally a secondary growth oak hickory forest, and some of the succession oak trees near the field house are among the oldest in Fairfax County.

A few of the plant species identified included cherry trees growing along edge habitats, sunflowers along creeks, ironweed in forested areas, sugar maple trees which flower in May, and poplars, which are among the first trees to sprout after a forest is cleared.

However, some of the other plants found on the walk are dangerous invasive species which threaten indigenous flora. Some of these included garlic mustard which is pervasive along waterways, as well as English ivy which threatens to strangle many of the native trees. Additionally, most of the grasses around campus are endemic to northern Europe and suboptimal for a piedmont habitat.

In explaining why invasives wind up on campus, Weeks offered several explanations:

“Sometimes settlers would bring in plants they planned to use as crops, but they didn't work out. Other times people would use a plant in their landscaping, and it spreads. Sometimes plants would travel in a ships' ballast.”

In pointing to a white mulberry, Weeks noted that these plants were brought in during colonial times to provide feedstock for silkworms, but because silkworms cannot live in this area, the trees have spread across the Atlantic coast.

Weeks was assisted by one of her graduate students, Kristen Baird. Baird is earning her masters degree in environmental science & policy in hopes of becoming a naturalist. Other students in attendance included members of Weeks' plant biology course. Some of the other courses taught by Weeks include plant taxonomy, plant communities and economic botany.

“I really do enjoy giving tours,” said Weeks. “It's one of the best parts of this job, to introduce people to the plants they see every day.”

Students who wish to accompany weeks on future walks or volunteer in the GMU Herbarium are encouraged to contact her at aweeks3@gmu.edu.