Pining for prairie

The hot saw can grab and cut several trees at a time. One operator removed about 4,000 trees in a single day.

The sub-zero temperatures in early March could not have come at a better time for restoration work at the Hastings Sand Coulee Scientific and Natural Area. While others lamented the persistence of winter, we rejoiced. The deep cold and snow were essential for removing a pine tree plantation — the first step in restoring the area to the sand-gravel prairie that it once was.

Work began on Wednesday, March 5, when one operator on a hot saw tree cutter cut and stacked the entire six-acre stand of pine trees, about 4,000 trees. At times the cutter removed 10 or more trees per minute, all with minimal disturbance to the ground. On Thursday and Friday skidders moved all the trees to a staging area at a degraded part of the site. The machines have huge tires to reduce soil compaction, and the deep snow and cold prevented damage to prairie vegetation.

If the cold weather had held a few more days, the grinder and semi trailers would have arrived to chip and haul the wood away. Spring could not be held at bay any longer, however, so the trees will have to wait until the ground is thawed and firm again. Once chipped, the estimated 22 semi-loads of wood will be taken to District Energy in Saint Paul to be burned to heat downtown buildings.

This project was part of a new woody biofuels initiative, funded by the legislature and coordinated by the Minnesota DNR Ecological Resources Division, to combine ecological restoration with energy production. Many ecological restoration projects involve removing non-native trees and shrubs, which are often burned on-site, resulting in a lot of wasted energy. If the material can efficiently be brought to the power plant, everyone benefits. It can be sad to see trees cut down, but ultimately the restored prairie will bring more diversity and important habitat to the landscape. With less than 1 percent of the original prairie remaining in the state, restoring what we can is critical to retaining that unique community of plants and animals.

Viewed from the entrance to the Scientific and Natural Area, this stand of non-native trees was targeted for removal as part of the restoration of the native sand-gravel prairie.

The cut trees were stacked for later removal. Note the wide tires on the tractors, chosen to reduce soil compaction in this sensitive natural area.

Photo by Ellen Fuge/Minnesota Department of Natural Resources