Study: Removing biomass from forests does no harm and prevents fires
Things are changing in the woods. In the past, loggers would cut down trees, and take the trunks to the sawmills and pulp mills, and leave the tree tops and branches on the ground to rot and feed the soil, to support the next generation of trees.
About a year and a half ago, the Iron Range 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 tops and branches and hauling the chips to the boiler.
Don Arnosti was one of many environmentalists who worried about how much of that biomass could be removed from the woods without harming the forest. He was also aware of another problem: 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," says Arnosti, a forestry expert with the non-profit Institute for Agriculture and Trade Policy in Minneapolis who organized the study.
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Arnosti recruited some university researchers, loggers, and officials from the Superior National Forest. They set up a series of nine experimental biomass harvests.
Their goal was to answer three questions:
How much biomass can sustainably be removed from the forest?
Is it possible for loggers to make a living harvesting fuel for renewable energy?
And can that harvesting reduce the cost of fire prevention?
The study reassured him about the first question, says Arnosti, who believes it's hard to take away 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."
It's just hard to pick up those small pieces of wood.
One of the loggers involved in the experiments, Lonny Popejoy, tried out a cutting head used in Europe for harvesting biomass. He found he couldn't make a living that way: the pay for the product doesn't approach 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."
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 also blamed federal red tape for getting in the way of an economically feasible harvest. The U.S. Forest Service has rules that apply everywhere in the country that probably don't make sense when loggers are trying non-traditional harvests. And those rules can slow down the operations drastically, the study found.
They study taught the officials at the Superior National Forest a lot, says spokeswoman Kris Reichenbach. They're excited about the potential to save money on removing fuel for forest fires. She calls it value-added forest management.
"If there is a market, 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."
Loggers need more money to do the work, they say. Either the forest service should pay them something for removing the fuel, or the biomass customer should pay more for the product.
Terry Leoni is that customer. He manages the electric utility in Virginia. Half the electricity he produces comes from burning wood. He pays what he can afford.
"It's based on economics of the plant and the dynamics and forecasts and projections that we put together on the plant. It's all market-driven."
He can't count on getting anywhere near as much wood as he needs from thinning activities in the Superior National Forest, Leoni says.
It is a complicated business. Everyone will have to work together to make biomass work, Don Arnosti, who organized the study, says. Land owners, land managers, loggers, and end users have to work together.
"And any one of those parties could screw it up; not make the changes, not make the adaptations, not cooperate with the other parts of this supply chain, and what we'll have is a lack of markets or a lack of harvest or a very inefficient system."
There are plans for small-scale biomass burners in cities and businesses and even schools all over Minnesota.