Assessing impacts of forest harvesting—The Minnesota experience

In late 1989, because of concerns related to a major expansion of the forest products industry, the state of Minnesota commissioned a Generic Environmental Impact Statement (GEIS) to assess the cumulative impacts of timber harvesting. Total harvest, primarily for pulpwood, was increasing from 3.5 million m3 in 1975 to an estimated 9 million m3 in 1992. The GEIS examined the direct impacts of forest management at three alternative levels of annual harvest, base (9 million m3), medium (11 million m3), and high (16 million m3). Ten major issues, ranging from economics to biodiversity and aesthetics, were considered. Using a 1990 forest inventory of over 13 000 plots, and computer models that optimized management goals and minimized costs, harvesting scenarios were generated by 10-year increments over a 50-year planning period. The results of the scenarios were evaluated in the context of the major issues of concern. The GEIS, completed in 1994, concluded that harvesting at the base level would be sustainable if recommended mitigation strategies were implemented. The projected impacts at the medium and high levels differed in degree rather than in type compared to those occurring at the base harvest level. Harvests exceeding about 12.5 million m3 were only sustainable if substantial investments were made in forest management. Through political consensus arising via the GEIS, the 1995 Minnesota Sustainable Forest Resources Act appropriated $1.74 million over 2 years to address site-level impacts, establish an information cooperative, establish a research advisory committee, develop a framework to coordinate landscape planning, encourage certification and education for forestry professionals, and provide technical assistance to private landowners. Although the GEIS did not answer all questions dealing with forest management in Minnesota, it clarified the issues, identified gaps in information, and helped bring interested parties together in setting the course for forest management in the next millennia.