Between climate change and invasive pests, there’s increasing pressure on our tree populations. Ready for the good news? MPCA awarded an Environmental Assistance Grant to the Mississippi Park Connection (completed June 2019), and the results could fill a forest.
A nonprofit partner of the National Park Service, Mississippi Park Connection leveraged the MPCA grant — along with a full-time Minnesota GreenCorps member — to build and operate a gravel bed tree nursery as part of its “Plant for the Future” initiative.
By placing bare-rooted stock in an irrigated pile of gravel for three to six months, the trees develop fibrous root systems. A rock nursery gives saplings a head-start towards a successful transplant: these trees experience less shock and higher survivability.
Staff and volunteers built the gravel nursery in one of the large planters on the front lawn of the Science Museum of Minnesota, located along the Mississippi River in St. Paul. It’s also near Shepard Road, where hundreds of the newly raised trees are now planted. The installation will support tree growth in the city for years to come as well as serve as an educational tool for the public and forestry professionals alike.
This tree-readying technique also offers a significant financial savings over balled or containerized saplings — and cost is no small factor. “We are replacing 72-miles of ash trees in the Mississippi National River and Recreation Area,” says Mary Hammes, Environmental Stewardship and Volunteer Manager for Mississippi Park Connection. The program aims to plant 15,000 trees by 2021 in response to the loss of ash trees to emerald ash borer. The new plantings are diverse tree species that will withstand Minnesota’s changing climate.
The success of this first project led Mississippi Park Connection to launch six additional gravel nurseries. In total, the gravel beds have replaced over 6,000 trees.
Hammes gives much credit for this climate change mitigation project to its Minnesota GreenCorps members. She says they’ve participated in everything from identifying the problem to building beds and organizing plantings. “One corps member, Dan Wattenhoffer, calculated that the number of trees we’re replacing store enough carbon dioxide to balance the use of 70,000 cars on the road annually.” Minnesota GreenCorps is a program coordinated by the MPCA that places AmeriCorps members with host organizations around the state to assist with environmental and sustainability initiatives.
MPCA is enthused by their success. Laura Millberg, MPCA's grant manager for the project, says "We encourage Minnesota communities to plant resilient trees as an effective strategy to adapt and increase resilience to our changing climate. Trees remove carbon dioxide, reduce stormwater runoff, absorb air pollution, and lessen urban heat. Bare root trees grown in gravel bed nurseries are a low-cost, proven approach.”
The benefits from this project, like the trees, should only grow.