Catastrophic wildfire kills practically all vegetation and can devastate entire watersheds, resulting in deposits of ash and other sediments in salmon spawning and rearing habitat. Forests throughout the Inland West were shaped and maintained by wildfires of various intensities. After decades of successful suppression, fire no longer plays the natural role it once did in maintaining the numbers and types of trees best adapted to particular sites. A result has been overcrowded stands of trees poorly suited to their sites. This encourages insect infestations and disease epidemics that weaken and kill trees, creating hazardous fuel conditions and severe wildfires. As an example, the 1989 Tanner Gulch wildfire devastated more than 3,500 acres in Oregon’s Grand Ronde Basin. 13 Intense rainstorms finally extinguished the fire, but ash and sediment destroyed much of the salmon habitat in the upper Grande Ronde River. The effects of the fire killed both adult and juvenile salmon. Such events demonstrate the necessity of active forest management to thin out dense forests, reducing fire hazards by restoring more natural conditions. This is especially important in the drought- and insect-ravaged inland forests of Idaho, Oregon, and Washington.
Timber Growth and Mortality Trends
Idaho’s Boise and Payette National Forests provide habitat for salmon. On both forests mortality rates exceed growth rates, meaning that the forests are dying faster than they are growing due to forest health problems.
Forest Health Conditions in Idaho, Nuiv. of Idaho, Idaho Forest, Wildlife and Range Policy Analysis Group, Report No. 11, Dec. 1993
Forest managers must continue to adapt inland and coastal management practices to provide quality upstream fish habitat.
Early-day loggers did their best to provide materials for a growing nation, but we now know that logging practices used then were less than friendly to salmon habitat. As recently as 45 years ago, loggers used “splash dams” to store enough water to carry logs downstream to mills. Releasing such large volumes of water caused torrents that altered stream courses and removed protective streamside riparian vegetation. Improperly placed or poorly designed roads have restricted stream channels or caused increased sedimentation. These roads were built when society’s needs were different than today and road technology was not as advanced. Previous tree-harvesting practices, including government-required removal of large woody debris from streams, also contributed to the reduction of fish habitat.
Research has shown quality fish habitat requires large in-stream woody debris, strearnside riparian vegetation, hiding and thermal cover, and suitable water temperatures. Northwest states all have stringent regulations to ensure quality forestry operations, including the retention of trees near streams. Current logging practices in coastal and inland forests utilize high standards that protect waterways. This is accomplished by carefully moving logs to avoid soil disturbance, protecting waterways and adjacent sensitive areas with buffer zones, and properly designing road systems. Foresters use state-of-the-art techniques to manage inland and coastal timber stands. These management activities include extensive replanting with a variety of tree species to provide a diverse, healthy forest. Management techniques, including harvest practices, reforestation, and specialized road engineering standards, are continually being improved to protect habitat and provide wood products at a sustainable rate. Foresters are actively managing riparian areas and streams to enhance habitat over time.