position statements: fish and riparian forests
position
The Oregon Society of American Foresters believes that most state and federal regulations that restrict forest practices in riparian areas in Oregon will benefit fish habitat over time. However, in some locations, forest thinnings and other active management of riparian areas could reduce natural risks (e.g., severe wildfires) or accelerate desired improvements in streamside conditions and fish habitat. Additionally, fish populations can be greatly affected by many human and natural factors other than forest practices and well beyond forest lands. Thus, proposals to further restrict forest practices should be based on credible scientific analyses of all major influences and a wide range of policy alternatives. To achieve this we believe that more extensive research is needed to help identify practices and policies for all primary land uses that are most cost-effective in improving aquatic habitat and fish populations. Furthermore, if public agencies determine that changes in management practices on private forest lands are necessary to achieve public benefits, policy approaches other than regulation (e.g., education, incentives) deserve serious consideration.
issue
In the 1990s, populations of many wild anadromous (ocean migrating) fish species, declined to record lows in the Pacific Northwest. This generated widespread concern about the effects of human activities on these populations. Riparian forests along streams in the region are known to provide important ecological functions that benefit habitat of many fish species. Because timber harvesting and other forest practices may temporarily alter some of these functions, concerns have been raised that these practices cause unacceptable impacts to fish habitat and that further regulatory restrictions are needed.
background
Low populations of wild salmon and other anadromous fish in the Pacific Northwest have increased public concerns about management practices that may affect fish habitat. Forest practices are of particular interest because many anadromous fish spawn and rear in forest streams, and important influences of riparian forests on aquatic habitats are now more widely recognized and understood. For example, trees that fall into streams can help create deep pools that provide key rearing habitat, and riparian vegetation supplies leaves and other material that help sustain the insects that fish feed upon.
Anadromous fish migrate over vast distances beyond forest lands and live for extended periods in a variety of other habitats. Their numbers can be greatly influenced by many non-forest management factors, such as hatchery practices, agriculture activities, dam construction, and urban development. Ocean conditions, harvest by humans and natural predators, and weather cycles that affect food supplies can be very important. Although the relative effects of these diverse human and natural influences have not been well defined, substantial increases in fish numbers in the 2000s in the region do indicate that forest practices are only part of a complex array of environmental influences.
Forest practices clearly have the potential to alter the aquatic environment. In the past, poorly conducted logging practices were shown to cause erosion, stream sedimentation, and warmer water temperatures. Habitat was also reduced when woody debris was removed from many streams in the mistaken belief that it was harmful to fish. Such findings led to implementation of the Oregon Forest Practices Act in 1972, and to major rule revisions in 1994 that markedly increased protection of riparian areas on private lands. On state and federal forest lands, recently updated forest plans have mandated even greater restrictions for riparian areas. Habitat improvements from these policy changes are expected to increase, but may take many years to accrue.
Relative to other human influences, the need to further restrict forest practices in Oregon's riparian areas to improve fish populations is not clearly supported by objective scientific analyses, and such limits may delay desired improvements in fish habitat in some streams. For example, natural additions of woody debris to streams and regeneration of desirable riparian tree species can take decades. Active management can accelerate habitat benefits where they are a high priority, by carefully applying professional forestry, fisheries, and hydrology expertise. In areas threatened by fire and forest health hazards, the benefits of active management can far outweigh the risks of inaction. Carefully designed research can help identify practices and policies that are most cost-effective in improving aquatic habitat and fish populations.
Current riparian management restrictions that retain valuable timber and affect adjacent operations already represent a significant cost to many private landowners in Oregon. Where fish habitat improvements are needed to help address impacts of historical activities or current environmental influences other than forest practices, policies that encourage education and landowner incentives deserve thorough consideration when public benefits are desired from private lands.
selected references
Hobbs, S.D., J.P. Hayes, R. Johnson and others, eds. 2002. Forest and stream management in the Oregon Coast Range. Oregon State Univ. Press, Corvallis.
Ice, G.G., J. Light and M. Reiter. 2004. Use of natural temperature patterns to identify achievable stream temperature criteria for forest streams. Western Jour. Applied Forestry 19(4):252-259.
Ice, G.G., P.W. Adams, R.L. Beschta and others. 2004. Forest management to meet water quality and fisheries objectives: Watershed studies and assessment tools in the Pacific Northwest. In: G.G. Ice and J.D. Stednick (eds.), A century of forest and wildland watershed lessons. Soc. Am. Foresters, Bethesda, MD.
Salo, E.A. and T.W. Cundy, eds. 1987. Streamside management: Forestry and fisheries interactions. Contribution No. 57. Institute of Forest Resources. Univ. Washington, Seattle.
Stouder, D.J., P.A. Bisson and R.J. Naiman, eds. 1997. Pacific salmon and their ecosystems: Status and future options. Chapman and Hall, New York, NY.
Adopted April 13, 2005. This statement will expire April 13, 2010, unless after thorough review it is renewed by the OSAF Executive Committee.