Amur honeysuckle, an aggressive invasive species, has proliferated throughout eastern North America, including at the Lilly Arbor, a restored forest site where the students are working for service-learning credits through IUPUI’s Thematic Learning Communities program. By removing this exotic shrub, the students help create a better habitat for animals and other plants. Eradication of the nonnative honeysuckle also helps improve local and regional water quality. Many of the characteristics that make honeysuckle exceptionally good at competing with other plants also make it exceptionally poor at holding soil in place, so an area infested with honeysuckle is likely to contribute to sediment loading of local waterways.
The students prepare to wander through the 17-year-old forest, arming themselves with gloves, trash tongs, bags and loppers provided by the center. Lopping is one of two methods used to attack the honeysuckle problem; the other is to pull plants out by the roots. After a few minutes of learning about the history of the Arbor site, and the characteristics of honeysuckle that contribute to its status as a pernicious pest, students are sent out into the forest in teams of two. The honeysuckle grows mostly on the perimeter, as the dense tree canopy does a good job of thwarting its growth in the forest interior.
Photos by Liz Kaye, IU Communications
This is but one of many days that center staff will spend with students doing service learning. Service projects often focus on the removal of invasive species, but wetland and prairie restoration, as well as weeding and winterizing an urban farm, are also on the docket for this semester. Working with a variety of community partners, the Center for Earth and Environmental Science offers a number of service-learning projects each semester for IUPUI students.
As an example, the Lilly Arbor site along the eastern banks of White River near IUPUI – where the students are now working – is co-managed by the center and the Indianapolis Department of Parks and Recreation. While the site really is an arbor of sorts, the name is actually an acronym that stands for Answers for Restoring the Banks Of the River.
Lilly Arbor research project
The Center for Earth and Environmental Science established the Lilly Arbor project in 2000 with help from the Eli Lilly Foundation and other groups. The forest serves as a location for service learning, but it’s also a long-term restoration project of the center.
“The river floodplain was formerly just turf grass from water’s edge to the base of the levee,” Schmalhofer explained. “Forest is the natural type of vegetation that should be growing in the area.” So center staff set out to reestablish a native forest along the river.
Volunteers from IUPUI and Lilly planted more than 1,300 trees, with each sapling receiving its own ID tag. Twelve different species of trees were established in eight plots, four to the north and four to the south of the Michigan Street bridge.
The project was intended to answer a number of questions about planting methods and tree survival:
Would older, taller saplings with established root systems – “containerized” trees – survive better than smaller, i.e., twig-sized, bare-root saplings?
Would the addition of weed mats improve survival of small, bare-root saplings?
Would the pattern of planting – random arrangement versus rows – affect tree survival?
What about honey locust versus silver maple? Swamp white oak versus willow? Would some species survive the conditions along White River better than others?
In the early years of the project, it became clear that having an established root system was advantageous for the saplings: The containerized trees had better survival than bare-root trees. It has not yet been determined, however, whether this initial advantage persists over the long term. One of the more curious discoveries was an unintended consequence of using the weed mats.
Photos courtesy of the Center for Earth and Environmental Sciences
Schmalhofer explained: “We had a winter without a lot of snow. So the sun was shining down on these exposed black mats, heating up the ground beneath them. Voles came in and started living under the mats because it was nice and warm under there. And voles eat plant roots.
“Living under the weed mats, the voles were, of course, quite likely to find the young saplings and nibble on the roots. By the following spring, a fair number had been nibbled clean through and had fallen over, quite thoroughly dead.”
Fortunately, hawks and other raptors, attracted by the high concentration of small mammals, were a common sight in the area during this time. The hunting activity of these predatory birds likely prevented vole-related tree deaths from being even higher.
The forest has definitely flourished along the banks of the river, and a full canopy now towers over what was once bare lawn. And – spoiler alert – the silver maples have done very well.
One of the most vital goals of the Arbor research was to discover which types of trees would best survive the conditions along White River. Although early survival patterns of those tree species can now be seen, ultimately survival of riparian forests, like the Arbor, will be determined by future generations. Therefore, educating those students is an essential element of the center’s purpose.
“Over the past five years or so, the center has focused a lot more time on environmental education,” said Schmalhofer, “especially on our Discovering the Science of the Environment program.”
Staff from the center frequently travel to middle schools and high schools in Central Indiana to deliver experiential science programs that include demonstrations such as a tornado in a box. Through a grant from the Duke Energy Foundation, the Center designed and built a new mobile lab that helps make these traveling programs possible.
Hands-on science is even more fun when schools have natural areas nearby that can be used as living laboratories. With a pond or stream nearby, students can sample the water, looking at it from a chemical or physical perspective, or even do an aquatic invertebrate analysis and look for creepy crawly critters. Schmalhofer said, “It gets the kids outdoors and exploring their world – that’s one of our main goals. No child left inside!”
The Center for Earth and Environmental Science is a water research center with an overarching goal of improving water quality in Central Indiana. The different focal areas at the center – service learning, research and education outreach – show how broad that theme can be. Students learn how to identify and remove dangers to the water supply. Researchers continue to examine environmental impacts. Starting environmental education in the middle schools may have the most lasting impact of all.
“We try to help the students see a bigger picture,” Schmalhofer said. “During service-learning events, I explain how removing invasive honeysuckle is actually improving water quality, both here in Indiana and down south in the Gulf of Mexico. The students like knowing that the work they are doing has real, tangible benefits. But they need to know that environmental stewardship is a matter of perseverance as well. There is a reason that Amur honeysuckle is called an invasive species – it is really, really good at getting into an area and getting established. We remove it. It comes back. We remove it again …”