Eric Moore, Grappling with Invasive Plants in Urban Forests

Eric Moore’s research asks what urban forests will look like in 2050 or 2100 if we do nothing about nonnative invasive plants. What if no trees sprout to replace current urban forests?

Moore, a Ph.D. candidate and DENIN Environmental Fellow, studies the effects of nonnative invasive species (hereafter simply “invasives”) and urbanization as drivers of change in urban forests. He’s looking at how nonnative, invasive multifora rose affects species diversity among seedlings, saplings, and annual plants. His research is conducted in extreme southeastern Pennsylvania and northern Delaware, in forest fragments of about 3–20 acres.

If land managers try to remove multiflora rose or other invasives, another species often takes its place. This “secondary invasion” typically happens if there’s no follow-up treatment after removing invasives. This may occur because invasives are not native to a place and may therefore lack other organisms to help control them. For example, deer often don’t eat nonnative plants.

Moore wants to know if we can prevent the need for ongoing maintenance at sites where invasives are removed. He is comparing the results of three forest management treatments: 1) remove invasives; 2) remove invasives and plant native seeds or plants; and 3) remove and mulch invasives, then use the mulch as a carbon-rich soil amendment to prevent establishment of invasives. One aspect of the field work has him examining the seeds present in the soil: do native or nonnative seeds predominate?

Invasive plants first grabbed Moore’s interest in Cherokee Park, in Louisville, Kentucky, which was designed by renowned landscape architect Frederick Law Olmstead. For an independent study during his bachelor’s and master’s degrees at the University of Louisville, Moore conducted a woodland restoration project in conjunction with the city parks system. His team removed 11 invasive plant species and reassessed the areas 7 years later. They found that secondary invasions were common.

Moore also interned at Bernheim Arboretum and Research Forest, south of Louisville. There he gained hands-on experience in choosing and safely using herbicides, using different kinds of land management equipment, and understanding how restoration can change a forest.

Moore came to UD to work withTara Trammel, John Bartram Assistant Professor of Urban Forestry in the Department of Plant and Soil Sciences. She completed a Ph.D. with Moore’s master’s advisor in Louisville. Moore is now about halfway through his Ph.D.

He intends to stay in academia. After finishing his Ph.D., Moore will seek a postdoc, preferably somewhere close to UD, so he can see some of his restoration projects through to completion. “They’re my babies,” he says, “and I want to see what a difference the time and effort invested in managing invasives can make.”

Moore enjoys being out in the forest, removing and counting plants. He enjoys the interactions with passersby who are interested in what the team is doing and frequently want to know how they can help. “People want to understand the natural world,” says Moore. “Urban parks may be their primary exposure to nature.” He enjoys seeing the common bond that nature can create among people.

Along with hiking and biking with his wife, Moore relaxes by playing improvisational blues and jazz guitar, mandolin, and bass. He especially enjoys the challenge of trying to incorporate an instrument such as the mandolin into musical genres, such as jazz, where it’s not normally heard.

by Joy Drohan, Eco-Write, LLC

Photo: Moore points out the extent of nonnative plant invasion and its effect on native trees near woodland edges in a nature preserve in southeastern Pennsylvania. Several invasive species, including multiflora rose, have surrounded and grown into the canopy of a native black walnut tree. Photo Credit: N. Jackson