Planting forests for the future

By Mike Curran, Minnesota GreenCorps Member 2021, Mississippi Park Connection

When we think of the term “climate adaptation,” our minds might drift to sea walls constructed around New York City, or raised sidewalks in Miami Beach. Further inland, the urban forests along this winding national park face their own climate change challenges, as habitat once considered suitable to native tree populations becomes inhospitable to many. In response, park volunteers have, quite literally, taken adaptation into their own hands.

Surly Gives A Damn volunteers plant trees in the floodplain forest at Lilydale Regional Park in Saint Paul.

Our Plant For The Future campaign established 15,000 native trees and shrubs throughout the national park in response to emerald ash borer. Volunteers also planted some climate-adapted trees, such as disease-resistant elm and yellow poplar. In total, 64 tree species were planted over five years. This diversity will make the Mississippi River’s urban forests more resilient to changing conditions and emerging diseases. Climate adaptation has become a central motivator to all of our restoration efforts—and what better way to tell the story of Minnesota’s changing climate than through the trees themselves?

A good place to start is with the bur oak, a tree commonly found in Minnesota’s prairies and savannas. Fortunately, these familiar friends are projected to do well in a more variable climate, due in part to their tolerance to a range of soils, from the most saturated to those exposed to prolonged drought. A great location to see young bur oaks is at Coldwater Spring, where the Coldwater Crew has been working for a decade to regenerate an oak savanna.

Volunteers plant future-climate-adapted trees at Pig’s Eye Regional Park in September, 2020.

Hackberry is another highly tolerant species that volunteers have planted up and down the river. Though most often found in the floodplain, hackberries have gained popularity in urban landscapes given their ability to thrive in poorer soils. Since 2017, volunteers have planted more than 1,300 trees, including dozens of hackberries, at Saint Paul’s Pig’s Eye Regional Park.

A newer arrival is the American sycamore, which might call to mind the forests of the southeastern United States. However, as Minnesota’s iconic winters lose their edge, this rapidly growing species will take root along the Mississippi River. This past fall, volunteers assisted the sycamore’s northern migration by establishing dozens at Settler’s Island in Cottage Grove.

Crosby Farm Regional Park is now home to 24 1-acre tree research plots as part of the ASCC initiative.

All of these trees figure into the Adaptive Silviculture for Climate Change (ASCC) research site at Crosby Farm Regional Park, where more than 300 volunteers gathered last May to plant 1,200 trees, setting in motion a 20-year study of various adaptation strategies. One year in and the vast majority of these future-adapted trees survived their first Minnesota winter thanks to the Crosby Crew—a group of volunteers who look after the study site.

No matter which part of the river you live closest to, our 2021 planting season will introduce thousands more future-adapted trees to this national park. With your help, we’ll ensure these trees find solid footing in our transforming river valley ecosystems.