BOSTON (AP) — Massachusetts officials have adopted final regulations for the state's biomass energy industry.

Officials say the new rules are designed to set a high standard for the wood burning power plants.

Regulators said they were looking for the best rules to govern the use of biomass resources for energy — including trees — in a manner that is consistent with the state's commitments to reduce greenhouse gas emissions and protect forests.

One regulation would require all biomass units to achieve a 50 percent reduction in greenhouse gas emissions over 20 years.

Wood power advocates have said stricter standards would make it harder for the plants to be economically viable.

Environmental activist calling the rules a model for the nation.

The final regulations come after two years of review and public comment.