From the NRDC (Natural Resources Defense Council):
"Right now Congress is considering legislation to increase the amount of electricity production from renewable sources like wind, solar and "biomass" -- organic matter that can come from sustainable sources, but could also come from natural forests and grasslands. Biomass can be an important part of the solution, but we need strong safeguards to ensure that it comes from sustainable crops and does not involve destroying forest habitats or turning them into cropland and sterile tree plantations." Take action.
Related 2009 hearing before the United States Senate Committee on Agriculture, Nutrition and Forestry.
More resources in the library's catalog on biomass for fuel and energy.