Report of the 1986 Midcycle Resurvey of the Spruce-Fir Forest in Maine
- Maine Forest Service
Since the mid 1970's, Maine's spruce-fir resource has been the subject of much scrutiny. The extensive spruce budworm outbreak, coupled with important expansions in the pulp and paper and sawmill industries, greatly increased demands on the resource. To determine how much area should be protected against budworm losses, the State Legislature in 1980 commissioned an analysis of future supply and demand for spruce-fir in Maine. This study (James W Sewall Company 1983) showed that the 1980 spruce-fir harvest level, about 3 million cords per year, could not be sustained indefinitely, regardless of the size of the area protected from spruce budworm defoliation.
Recently, several developments have raised questions about these predictions. During 1984-85, the budworm outbreak collapsed more rapidly than expected, and by 1986 no operational spraying was needed in Maine. Several large landowners began to treat thousands of acres with intensive forest management practices designed to increase growth of young, developing stands. In addition, a perception developed that spruce-fir harvests would decline as outdated manufacturing capacity, no longer profitable in the increasingly competitive worldwide market, was gradually phased out. In reality the 1980-1986 harvest of spruce and fir was found to be larger than originally projected.
The 1980 supply-demand study required assumptions about harvest levels, the impact of the spruce budworm on growth and mortality, the ability of the forest to regenerate, and other factors. These assumptions could be checked with a timely remeasurement of the same plots used in that analysis, but the next assessment by the U.S. Forest Service was not scheduled until 1992. An interim or "midcycle" resurvey was needed to validate the earlier forecasts and to update them to account for new or unexpected developments. In 1985, the Maine Legislature directed the Commissioner of Conservation to "supplement these surveys with midcycle forest inventories in order to more accurately assess the changes and trends occurring in the forests of this State. Initial emphasis should be given to a midcycle survey in the spruce-fir resource" (12 MRSA, Sec. 5103). This report is an analysis and discussion of a portion of the data collected. Because the midcycle survey used only a subset of the plots sampled by the US Forest Service in the 1980 survey, this report can only be considered as supplementary to the US Forest Service report (Powell & Dickson 1984). The information contained herein does not supplant the US Forest Service report.
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