It is common for those considering biomass energy to ask: "What about the forest? In a larger role for biomass energy, will forest ecosystems be sustained?"
This is a complex, important question. Currently, in many parts of the country, most notably in the west, there are vast amounts of surplus wood residue from communities, sawmills, and logging operations that can be used for biomass energy without direct impact on forests. However, as we move toward reducing our dependence on fossil fuels, we will likely exceed these volumes of residue wood and eventually turn to our forests as a source of energy. If we do, it must be done sustainably.
Forest sustainability needs to be examined both at the regional landscape level and on the ground. BERC believes that harvesting, particularly for biomass energy, should be developed within the regional forest’s growth capacity. Additionally, the forestry practices and harvesting methods being applied locally should not adversely impact the long-term health and productivity of that region’s forests.
Wood fuel supply assessments, such as the Vermont Wood Fuel Supply Study, can assess whether harvesting is happening within the growth capacity of the region’s forests. Yet, determining whether on-the-ground forest management is sustainable is much more difficult to address: Each forest and its management is unique and can be highly complex. Certain harvest intensity and techniques used on one forest may be considered sustainable while the same intensity and techniques used on a different forest may be far from sustainable.
As the stewards of the forests, foresters prescribe management that balances the landowner’s objectives with the health of the forests. There are several emerging certification systems to ensure that management plans and harvesting are sustainable. Many of these certification systems set standards that must be met and use independent auditors to verify compliance.
In the end, people define forest sustainability in varying ways. Foresters themselves debate the answers to such key questions as, "What is the appropriate amount of wood to remove for a healthy forest? Should all tree tops from harvests be left, or only some?"
There are no blanket answers — the answer is always site specific and depends on numerous complex factors. Both regional and local fuel supply assessments are critical components to studying the viability of any biomass energy project.
For more information on BERC’s work with biomass fuels and forest sustainability, please see:
Vermont Wood Fuel Supply Study (PDF) Northern Forest Biomass Energy Initiative