ORONO, Maine — As more wood is used for fuel, the demands on Maine’s forests are changing quickly — and that might affect the long-term viability of Maine’s iconic industry, said attendees Tuesday at a conference at the University of Maine.

“More people don’t want to buy oil but would like to buy wood, or wood pellets,” said Tony Filauro of the Maine Division of the New England Society of American Foresters. “That means less wood for paper and less for lumber. It’s an increasing demand for a finite resource.”

Filauro was one of about 180 foresters who talked about the issues affecting the forests and possible solutions at the Society of American Foresters gathering, where plaid shirts and work boots were practically the dress code.

Maine has about 17 million forested acres in production right now, and ownership of those acres has changed dramatically over the last decade. Paper companies used to own most of the productive acres. Now companies such as Plum Creek own the land and sell wood to paper companies and others.

“There is an imbalance right now,” said John Williams, president of the Maine Pulp and Paper Association. “We have to be careful to continue to harvest wood sustainably.”

The exploding demand for fuel isn’t helping, officials said.

“Pellets are new. It’s a wild card,” said Dave Struble of the Maine Forest Service. “The other wild card in this is firewood.”

The price of firewood has gone up almost $100 a cord in the last couple of years, officials said.

Although Struble said that more wood is growing in the forests than is being harvested, the increased demand for wood pellets and biomass chips is exacerbated by the fact that loggers are having trouble getting to the trees.

Reasons for the harvesting difficulties range from the meteorological — such as last winter’s record snows — to the political, Williams said. The industry depends on a work force of about 700 Canadian foresters, especially in very productive forested areas in the northwestern part of the state. Some of those foresters have been caught up in a new federal immigration policy and can’t get their work visas.

Another problem is that there are fewer loggers nowadays, he said.

Williams also said that people in the industry are concerned that when trees get turned into fuels such as wood pellets and biomass chips, not much value is added to the raw material.

It’s a different story with paper and lumber, the more traditional end products of Maine’s forested land. Williams said pulp and paper might be worth about $1,000 a ton, while pellets can be sold for only around $300 a ton.

This is a worry to foresters, who don’t want high-value-added products to be replaced by a large demand for lower value-added ones.

“It’s fascinating to learn what people are paying and how they’re competing for the same product,” said Laura Audibert, a consulting forester in Fort Kent. “I’m more concerned about what that means for practicing forestry. You can burn anything. But you can’t make kitchen chairs or tables out of just anything.”