Topic: Silvicultural Alternatives to Clearcutting in the Old-Growth Forests of Southeast Alaska

Issue: Clearcut logging of old-growth forests is one of the most visible and contentious forest management issues in southeast Alaska. This issue touches the cornerstones of southeast Alaska's economic and social well being: the timber industry, fisheries, tourism, and subsistence. Broader concerns for biological diversity, threatened or endangered species, and the value of wild and remote places have placed this issue on the national stage. In response, the tendency has been to treat these values as competitors and to `zone' the forest for a restricted range of uses.

An alternative view proposes that there may be greater compatibility among these values than is commonly thought. Observations suggest that southeast Alaskan forests are well adapted to the widespread small- to medium-sized disturbances caused by wind, disease, and landslides. The use of silvicultural systems other than even-aged management with clearcutting could take advantage of this adaptation to provide a sustainable supply of timber¾ along with a host of other important values.

The alternatives to clearcutting (ATC) study uses experimental and retrospective approaches to evaluate several silvicultural systems¾including even and uneven-aged management¾ and their biological, physical, and socioeconomic effects. The ATC study integrates research on stand dynamics, forest health, understory plant communities, wildlife habitat, stream ecology, slope stability, hydrology, economics, visual quality, and social acceptability. The entire study is intended to assist natural resource managers in choosing management alternatives by providing essential information on the costs and benefits of adopting alternative silvicultural systems and by developing, testing, and refining systems for producing a wide range of forest values.

Findings:

· The purchase of two major ATC timber sales and the successful harvest of one demonstrated that ATC systems are viable in the current timber marketplace and that the treatments are feasible from technical and safety points of view. In general, residual trees at Hanus showed higher levels of harvest related damage in 25% retention prescriptions (top breakage in 5.2-10.2%, bole wounds in 4.0 to 26.8%) than in 75% retention prescriptions (top breakage in 3.4-4.5%, bole wounds in 3.4-6.4%). Group selection employing gaps with diameters of 200-300 feet was operationally efficient, but 100-foot gaps created severe difficulties during falling and yarding operations.

· Retrospective studies of historical partial cutting showed that the current proportions of Sitka spruce and western hemlock depend more on initial stand composition than cutting intensity. Also, small and medium size residuals--not new germinants--dominate current stand species composition, basal area, and growth. This indicates that cutting intensity has little effect on the proportions of more- and less-desired tree species in future stands, and that low-intensity cutting will not cause stands to become dominated by western hemlock and devoid of Sitka spruce.

· Partial cutting appears to maintain diverse and abundant understory vegetation, comparable to adjacent uncut old-growth stands. Some key deer forage species decreased with increased cutting intensity, but overall plant diversity and abundance was still higher than in heavily cut stands.

· Studies of winter wrens in even-aged and uneven-aged stands showed that reproductive success of this common bird is affected by stand structure. Wrens nesting in the even-aged stand had lower nest success, fewer mates, and larger territories than birds living in partially harvested stands. This indicates that clearcutting can adversely affect these birds long after the harvest itself is over.

Management Implications:

· Harvesting of the remaining two ATC sites will, of course, give us a sounder basis for judging ATC treatments, but nothing we have observed at Hanus Bay should prevent managers from cautiously prescribing and implementing ATC systems.

· This indicates that low-to-moderate intensity partial cutting of old-growth hemlock-spruce forests may be a feasible alternative to clearcutting where management objectives include maintenance of wildlife habitat and co-production of economically desirable tree crops.

Lead Scientists:

· Michael McClellan, ATC Study Co-Coordinator, Forest Ecologist, RMP

· Stewart Allen, Social Scientist, SEV

· Robert Deal, Forester, RMP

· Toni De Santo, Ecologist, ALI

· Paul Hennon, Plant Pathologist, MND

· Mary Willson, Ecologist, ALI

· Mark Wipfli, Aquatic Ecologist, ALI

· Richard Woodsmith, Hydrologist, ALI

Collaborators:

· Richard Zaborske, ATC Study Co-Coordinator, Regional Silviculturist, USFS Alaska Region

· John Tappeiner III, Professor, School of Forestry, Oregon State University

· Kermit Cromack, Jr., Professor, School of Forestry, Oregon State University

· William Sise, Professor, Humboldt State University

· James Burchfield, Professor and Director, Bolle Center for People and Forests, University of Montana

Many from the Tongass National Forest and the Alaska Region have been involved with the design, implementation, and monitoring phases of this research. They have gained valuable experience in the administrative and technical aspects of applying ATC prescriptions. Both scientists and managers have benefited from the meshing of practical and scientific concerns and from the continuing dialogue between them. In addition, the ATC study has garnered significant attention from the news media and the public¾ their positive response to this collaboration reflects well on both PNW and the Alaska Region.

Our university cooperators have gained the rare opportunity to participate in a very large-scale, integrated, experimental ecosystem study with good institutional support. Manipulative forestry research at this scale would be beyond the resources of most researchers without the assistance of the NFS. Several graduate students are gaining valuable research experience by conducting their thesis research on aspects of the ATC study. ATC is and will continue to be a unique resource for independent researchers seeking answers to questions within our integrative framework.

Priority: Wood Production Consistent with Sustainable Ecosystems