A state shaped by trees
Maine’s forests form one of the state’s defining natural systems. They provide wildlife habitat, store water and carbon, support recreation, and supply material for forestry and wood-products work.
A federal inventory published for 2015 estimated that Maine contained approximately 17.5 million acres of forest land. At that time, forests covered more than 89 percent of the state’s land area, and the total had remained broadly stable since 1960.
What the historical inventories measured
The 2015 inventory estimated nearly 24.4 billion live trees greater than one inch in diameter. Comparing the 2010 and 2015 estimates, above-ground timberland biomass increased by about 4 percent, average annual tree-growth volume increased by 18 percent, mortality decreased by 13 percent, and harvest levels declined by 18 percent.
Reading the figures
These values describe the period covered by the cited federal inventories; they should not be treated as present-day measurements. Forest estimates change as inventories are updated and as growth, harvest, disturbance, land use, and classification change.
Ownership and forest structure
The cited reports characterized approximately 90 percent of forest land as privately owned, with public ownership—including some reserved lands—accounting for around 10 percent. Ownership matters because management objectives, public access, conservation arrangements, and harvest decisions differ across parcels.
Although statewide forest area had remained comparatively stable, the reports noted that timberland could be declining slightly. They also described the white, red, and jack pine forest-type as continuing to contain a substantial area dominated by large-diameter trees.
Disturbance and long-term change
Maine’s forest structure reflects natural disturbance and management over time. The spruce budworm outbreak and subsequent salvage operations of the 1980s and 1990s affected broad areas of timberland. Forest conditions continue to develop as stands age, regenerate, or undergo harvesting and other disturbances.
Statewide totals are useful, but they do not make every forest alike. Species composition, age, soils, elevation, moisture, ownership, and management history vary considerably from one part of Maine to another.
Sources and scope
This overview summarizes historical figures from the United States Department of Agriculture publications Maine Forests, 2013 and Forests of Maine, 2015. It preserves their period context rather than presenting the figures as current conditions.