Battling Buckthorn

PHOTO: Ecologist Joan O'Shaughnessey
Garden ecologist Joan O’Shaughnessey wields her weapons of choice.

Our weapons: saws and loppers.

Before our might, the foliaged foe fell along a stretch of the Green Bay Trail near the Braeside Metra station.

That’s where a group of 50 of us gathered to vanquish thickets of invasive buckthorn (Rhamnus sp.) on Wednesday, June 19. The removal was initiated by the City of Highland Park and the Park District of Highland Park in partnership with the Chicago Botanic Garden. Ravinia Festival also provided volunteers and space for parking and picnicking afterward.

“This was an ideal place to demonstrate what buckthorn control could accomplish through taking back our beautiful natural surroundings, even in very busy settings,” said Rebecca Grill, natural areas manager for the Park District. The area links two major cultural institutions serving the community, the Garden and Ravinia. It is also near a planned bike path for cyclists and pedestrians that eventually will extend to the Garden, connecting the North Branch and Green Bay Trails. 

PHOTO: the Park District team.
The Park District team included (left to right) Rachel Cutler, Dianna Juarez, Dan Malartsik, Liz Ettelson, Rebecca Grill, Ted Baker, Steve Meyer, and Chris Wilsman.

 

PHOTO: Sophia Siskel and helpers.
Sophia Siskel, the Garden’s president and CEO, brought her sons to help.

From 9 to 11 a.m. we sawed, chopped, cut, tugged, pulled, dragged, and stacked so much buckthorn that by the time a break was called, some piles were as high as me (5 feet), extending in an impressive line down the trail. Joggers, walkers, and cyclists made their way past the activity, occasionally cheering on the workers, including Garden President and CEO Sophia Siskel and her sons.

Why has buckthorn become such a problem in the Midwest? It’s the story of a plant species imported for perceived benefits that runs amok, crowding out less aggressive native plants and altering the landscape. Buckthorn arrived in the United States in the mid-1800s, brought from Europe as an ornamental plant admired for its thick, long-lasting foliage and fast growth. Native birds relished the fruits of the tall shrub and helped to disperse them. Once scattered, the seeds could remain dormant for as long as six years. In contrast to native plants, buckthorn supports almost no native invertebrates, like butterflies and moths, many of which are either food for native animals or serve as important pollinators. Soon buckthorn expanded far beyond its original boundaries of home landscapes and farms—where it was used as a windscreen—crowding out native plants, changing nutrients in the soil, and threatening native habitats. 

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Participants work to clear buckthorn near the Braeside Metra station and Ravinia Festival.
Buckthorn on Green Bay Trail
The cut buckthorn was dragged out of the way of cyclists and pedestrians using the Green Bay Trail.

How much buckthorn did we eliminate? Rebecca estimated that our group cleared 1,500 feet of trail—more than a quarter-mile. At 2:30 p.m.,  she and her crew were still feeding the cut plants into a wood chipper, making sure the chances of reseeding are minimal. They also selectively applied herbicide to the remaining stumps. In the future, they plan to monitor the area for the return of native wildflowers, seeding if necessary.

I live near the trail and run along it often. Already I have enjoyed seeing how the sunlight filters into this new clearing, reaching areas that will soon flourish with returning “natives.”

Rebecca Grill, PDHP, and Bob Kirschner, director of Aquatic Plant and Urban Lake Studies
Rebecca Grill of the Park District and Bob Kirschner of the Garden pause before tackling the buckthorn.

Learn more about invasive species on the Garden’s website. For information about future buckthorn workdays, contact Liz Ettelson at the Park District of Highland Park  (eettelson@pdhp.org). 


©2013 Chicago Botanic Garden and my.chicagobotanic.org

Simulating Summer in the Plant Science Center

Seeds of potential native winners from the Colorado Plateau.
Seeds of native species from the Colorado Plateau.

These seeds may not look like much right now, but the story they tell is full of adventure and promise. This week we are simulating summer in the Daniel F. and Ada L. Rice Plant Conservation Science Center to get them to reveal some of their secrets.

My research takes me to the Colorado Plateau (you may know it as the “four corners” region), which is one of the most starkly beautiful places in the United States. I work with many Garden scientists, graduate students, and public land management agencies like the Bureau of Land Management (BLM) to carry out research that helps make native plant restoration and management on public lands throughout the Colorado Plateau as efficient and effective as possible. We are particularly focused on understanding how to help native plants cope with encroaching invasive species, changing land use, and shifting climates.

So these seeds come from a gorgeous place. But more importantly, they were produced by some pretty impressive native plants that were tough enough to not only survive last year’s crazy weather, but to also flower and produce seeds in some pretty harsh sites. Like Chicago, the Colorado Plateau experienced one of the hottest, driest summers it has seen in a long time. Most of the plants in the Colorado Plateau sat out the flowering season last year — they conserved their resources for a better year. We are interested in the plants that braved really bad conditions to produce seeds, because we think they will be especially useful when restoring habitat that has been badly damaged by wildfire or invasive species. We call these plants native winners.

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Unfortunately, very little is known about what makes these native winners tick. Our research is helping to uncover some of their secrets. Alicia Foxx (a student in our joint graduate program with Northwestern University) and I have just set up an experiment that will reveal the specific seed germination requirements for these native winners. We are using incubators that allow us create spring- and summer-like conditions that will tell us when and why seeds of these species are able to germinate and grow. Knowing this information is just a first step in our research that will help us improve the outcome of restoration practices.


©2013 Chicago Botanic Garden and my.chicagobotanic.org

Green Roof Garden Update

Richard Hawke, plant evaluation manager, gives us an update on the Green Roof Garden one year after the opening of the Daniel F. and Ada L. Rice Plant Conservation Science Center. The Ellis Goodman Family Foundation Green Roof Garden South features regional and national native plants, many of which are not currently used as rooftop plants; the Josephine P. & John J. Louis Foundation Green Roof Garden North features a mix of plants known as good green roof plants, plus native and exotic plants that have potential for green roof use. Visit our website for more information.