<unning or walking through the pine plantation in the northern tip of the arb, one might not realize the obstacle it poses to restoration. Covering 30 acres, the dense pine forest holds quite a bit of wood. The pines aren’t native to this part of Minnesota. They occupy land that should bear oak forests or prairie. They shade out native plants, they spread pine trees to neighboring savannas, and prevent managers from balancing these nearby plots with prescribed burns. They’re also starting to die. As the pine population slowly turns to a stand of dry snags the risk of them snapping in a windstorm increases, making upkeep more time consuming and costly. In short it’s time for the pines to go.
Until recently the large scale removal of pine trees wasn’t an option, but just this year arb managers applied for and received a large grant for the removal of ten acres of the plantation, part of a long term plan to reintroduce native forest. The grant comes from the Minnesota Department of Natural Resources, and the removal of the pine will be conducted by private contractors. As soon as the ground freezes this fall the project begins, and the goal is to be finished by winter 2013. To prevent a resurgence in non-native species the removal of the pines will be followed up with herbicide treatment of any remaining invasives. Then native grasses will be planted to provide ground cover and prevent erosion, and from there either native grassland species will continue to be added as it’s transformed into prairie or native trees will begin to be planted.
From the perspective of the DNR, the goal of the biomass grant isn’t just to remove species harmful to native ecosystems. An underlying goal is to improve the market for biomass material. The biomass collected from the removal projects in the arb could be used for everything from bioenergy, to mulch, to pellets, to animal bedding. By funding this project, and similar projects throughout Minnesota, the DNR aims to contribute to these markets, help the businesses that use the biomass improve their methods, and ultimately make it easier and cheaper for landowners and managers to remove unwanted vegetation in the future. That’s a goal every restoration project can look forward to, and some of the progress will be made right here in Carleton’s Cowling Arboretum.
Brandon Valle ‘14, for the Cole
Student Naturalists