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Biomass is made up of tree branches and shrubs that could be used to produce electricity.
In the past, loggers who cut down trees would take the trunks, and leave the tree tops and branches on the ground to rot and feed the soil. About a year and a half ago, the cities of Virginia and Hibbing built a boiler that would burn wood to produce electricity. Since then, loggers have been chipping up some of the treetops and branches and hauling the chips to the boiler.
Don Arnosti, a forestry expert with the non-profit Institute for Agriculture and Trade Policy, was worried that removing too much biomass could harm the forest. He recruited some university researchers, loggers, and officials from the Superior National Forest for experiments.
Arnosti said the study reassured him that it would be hard to take enough biomass to hurt the forest or deplete the soil of nutrients.
“Even where we were targeting higher rates of removal, we were generally leaving about one-third of the biomass even when we were trying not to,” he said.
One of the loggers involved in the experiments, Lonny Popejoy, found that it was difficult to remove the biomass. He tried out a cutting head used in Europe, but he couldn’t make enough to pay for the cost of the equipment.
“Just that little harvester head was $80,000, so you wouldn’t live long enough to cut biomass to pay for that. My wages if you estimated my wages and the fuel for the machine, we didn’t even make that. We went into the hole on that,” Popejoy said.
A big part of the problem was the cost of fuel. Most of the test sites were on the eastern side of the Superior National Forest, nearly a 100 miles from the boilers on the Iron Range.
The study taught officials at the Superior National Forest a lot, forest spokeswoman Kris Reichenbach said.
“If there is a market (for biomass), of course the economics and the bottom line is going to be better for us as land managers, better for the operators, and better for the industry that’s using the biomass,” she said.
Loggers said they need more money to remove the biomass.
The study also found one additional advantage to removing biomass. The branches, and even young trees, provide fuel for forest fires.
“When you have high volumes of this material, you can have large catastrophic fires like we’ve experienced twice in the last couple of years,” Arnosti said.
He also said using biomass for fuel is complicated, and all parts of the business will have to work together.
There are plans for small-scale biomass burners in cities, businesses and even some schools across Minnesota.
