From 1967 to 1976, the overall level of harvest of spruce-fir pulpwood in Maine did not change appreciably. During this period, increased use of sawmill residue chips offset rising input requirements at Maine pulpmills so that roundwood consumption did not rise, although it fluctuated significantly from year to year due to changing markets, weather, and inventory conditions. From 1967 to 1975, chip production rose by more than 110%, from 176,000 to 375,000 cords.