Greencastle students take on invasive plant
GREENCASTLE -- Greencastle High School students spent part of Wednesday morning removing garlic mustard -- an invasive plant species detrimental to native plants and wildlife -- from a section of land along Big Walnut Creek near Dunbar Bridge.
"It suffocates and takes over the native plants that are necessary for wildlife," explained junior Brittany Girton.
Garlic mustard was introduced in North America as a culinary herb in the 1860s. Today, it is an invasive species throughout much of North America. Like most invasive plants, once it has an introduction into a new location, it persists and spreads into undisturbed plant communities.
The insects and fungi that feed on it in its native habitat are not present in North America, increasing its seed productivity and allowing it to out-compete native plants.
A study published in 2006 concluded that Garlic Mustard produces allelochemicals that harm mycorrhizal fungi that many North American plants, including native forest trees, require for optimum growth. Because white-tailed deer rarely feed on garlic mustard, large deer populations may help to increase its population densities by consuming competing native plants. Trampling by browsing deer encourages additional seed growth by disturbing the soil.
A complication to the eradication of Garlic Mustard from an area is the longevity of viable seeds in the ground. Seeds contained in the soil can germinate up to five years after being produced.
"People all over will be having garlic pulls this Saturday," said junior Clark Wilson. "They've been doing that since 2002. Garlic mustard can be found now in 84 counties in Indiana.
Wilson said garlic pulls are slated this weekend at Turkey Run, McCormick's Creek and Shades state parks.
"(Garlic mustard) is kind of in its own ecosystem," said junior Bryan Sanders. "There are no animals around here that eat it."
Junior Laura English explained that the plant is very hardy.
"It doesn't require a lot of sunlight, and it grows a lot sooner in the spring than a lot of other plants," she said. "It covers a lot of area. Really, all we can do is slow the spread by pulling it."
Teacher John Garner agreed.
"We kind of have to pick these small areas to save," he said. "It's just every place."
Students in Garner's class take a mini-field trip each Wednesday to an area in Putnam County. This Saturday, in conjunction with Earth Week, the students will be conducting a clean-up along Big Walnut Creek.