By Carol Savonen To early settlers and loggers, Oregon's forests seemed endless and inexhaustible. But in less time than it took to grow them, most of the original forests were harvested. Forestry was Oregon's leading industry for many decades. More than 40 percent of Oregon was once covered by native forests. These forests were important to salmon, for a supply of cool, clean water and rearing and spawning habitats. Since the mid-1800s, intensive timber harvest has affected salmon populations in coastal, interior and mountain forestlands. Aquatic scientists have studied the effects of timber harvest on fish habitat for many decades. They have learned that through the past century and a half, logging and road building and related activities altered salmon freshwater habitat in many ways. |
 Logging practices and associated road building have damaged salmon habitat. Today the forest industry is working with others to minimize its impact on salmon. |
For example:
- In the 1800s, trees were frequently removed from wooded riversides
and coastlines and floated away to mill sites. When the timber within easy
access of a navigable stream or river was exhausted, logging operations
moved on.
Heavily logged river valleys resulted in unstable soils, higher water temperatures and increased sediment deposits in spawning gravel. Food for fish declined and rearing habitat disappeared with the trees. The supply of large, woody debris that naturally formed the structure for fish habitat disappeared.
- Early logging operations built temporary structures called "splash
dams" across small streams in more than 160 locations on Oregon's
coastal streams and Columbia River tributaries. First, a dam was built
and filled with water. When it was blown up, mammoth logs roared downstream
in a huge torrent. These torrents of water and logs would scour stream
bottoms as logs pushed gravel off stream bottoms, leaving bare bedrock.
Salmon, their habitat and their offspring were often destroyed.
- After World War II, heavy equipment was used to harvest trees. Yarders, loaders, bulldozers and trucks came down extensive networks of newly built roads into areas formerly inaccessible to timber harvest. On federal lands, there is now an average of between 3 and 4 miles of road per square mile of watershed area, according to a 1993 Federal Ecosystem Management Assessment Team Report. Forest Service studies showed that where roads were built on steep terrain in the 1940s through the 1960s, the frequency of landslides increased dramatically compared to steep roadless terrain.
Mechanized timber harvest and associated road construction increased sediment into streams and raised stream temperatures. Inadequately designed road culverts blocked salmon migration to spawning areas. Until the 1980s, large woody debris was often removed from salmon streams because biologists thought it helped fish migrate upstream to spawn.
Gordon Reeves, a fish biologist with the U.S. Forest Service Pacific Northwest has investigated the impact of forestry throughout the Pacific Northwest, from Alaska to Oregon. He says we have changed our forest ecosystems in profound ways in terms of salmon habitat.
"We have altered the natural processes that originally created our forested and aquatic ecosystems," said Reeves. "You have all the immediate effects, like increased sediment into streams and increased water temperatures. But you also have to look at the big picture--we have harvested the timber to such a sheer magnitude, over such a wide area of land, so much more frequently than natural disturbances like wildfire occur--that the entire ecosystem is different.
"We no longer have significant large woody debris in the streams and rivers. Wood was the basis for stream structure, fish habitat. Wood, creating backwaters and pools, trapped spawning gravel, provided detritus [loose material] for the energy base of the stream. Wood was the glue that held together the whole stream and river systems. And wood is woefully inadequate now.
"If we want to restore habitat for salmon we are going to have to do more than pat ourselves on the back for putting a few logs here and there in a stream," continued Reeves. "We aren't acknowledging the causes of watershed habitat degradation--we are merely treating the symptoms. To have adequate habitat for wild salmon, we will need to manage whole watersheds, whole ecosystems differently. We aren't doing this yet."
However, Bill Arsenault, who operates a small woodland farm near Elkton and is a vice president of the Oregon Small Woodlands Association, has a different perspective. Arsenault says a study conducted by the Oregon Forest Resources Institute, a state-chartered organization, showed that about 90 percent of the forest land base in Oregon in 1600 exists today.
"What I'm doing on my place primarily is putting wood back in the streams," said Arsenault. "This is very important as an interim step [in improving salmon habitat]. Current forest practices are designed to allow the natural system to put wood back in the streams. But that's a long-term process."
Although timber practices are now changing for the better and public land managers are now protecting more areas for natural, non-consumptive uses including wilderness, wildlife, fisheries and water quality, the salmon will be affected by past forest practices for many decades, said Reeves.
But notwithstanding past problems, the healthiest remaining habitat for salmon is in some forested areas, said Jim Martin, an assistant director of the Oregon Department of Fish and Wildlife.
The forest industry, from large corporations to small-woodlot owners, has faced many changes because of regulations established to protect natural resources. Environmental laws, such as the Oregon Forest Practices Act on state and private lands and the Northwest Forest Plan on westside federal timber lands, are changing forestry practices. Buffer strips of trees must be left along most year-round streams to provide shade and a source of wood. Reforestation is required. Culverts are better designed to allow fish to pass, and road construction standards are much stricter. Fish and wildlife habitat must be protected in certain areas. On federal lands, watershed reserves have been set aside to help threatened species such as spotted owls and marbled murrelets, and these areas also help salmon.
"The Oregon Forest Practices Act is a dynamic statute--it is ever changing," said Ray Wilkeson, legislative director for the Oregon Forest Industry Council. "We have supported significant increases in the level of regulation over time. And we have complied, as long as the regulations are based upon science and newly learned information. For example, we are inventorying old logging roads because they have been a problem for water quality and fish in the past, and either rehabilitating or repairing them or putting culverts in them to provide safe passage for fish."
Today, the forest industry, university researchers, citizens in watershed councils and the government are working together more than ever to try to minimize forestry's impact on salmon habitat, especially in the Oregon Plan, to promote recovery of Oregon's native salmon stocks.
"We all want pretty much the same thing--to manage the forest so it doesn't degrade fish habitat," said Wilkeson. "But we don't want to be put out of business."