Eastside forest ecosystem health assessment

Everett, Richard; Hessburg, Paul; Jensen, Mark; Bormann, Bernard. 1994. Volume I: executive summary. Gen. Tech. Rep. PNW-GTR-317. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 61 p. (Everett, Richard L., assessment team leader; Eastside forest ecosystem health assessment). This report responds to the request by Speaker Foley and Senator Hatfield for a scientific evaluation of the effects of Forest Service management practices on the sustainability of eastern Oregon and Washington ecosystems. The report recommends analysis methods and management practices that can be used to build an experimental approach to the restoration of stressed ecosystems. A total of 113 scientists from universities, Federal and State agencies, and private companies, contributed to this report. Their research provides the basis for a sustainable ecosystem management framework to evaluate the effects of management practices on ecosystem sustainability, and recommends strategies for restoring or rehabilitating stressed ecosystems. Current and historical landscape attributes were characterized and compared for a 1.1 million-acre sample of river basins in eastern Oregon and Washington (Figure 1) in this assessment. Change in fish habitat conditions of four river basins was also studied. Terrestrial assessment data were compiled and interpreted with the assistance of more than 115 National Forest System employees. Spatial analyses were performed to determine differences in historical and existing vegetation patterns. Previous management practices were evaluated to determine their effects on current ecosystem conditions. The following changes in eastside ecosystem conditions have.occurred during the last 40 to 55 years: (J Forest fragmentation and landscape diversity increased in intensively managed watersheds, but declined in wilderness or roadless areas. CJ The acreage of early-seral, late-seral, and climax stands has decreased, while mid-seral stand acreage has increased. Additionally, the abundance of young and old forest structural stages has declined, and middle-aged structural stages have increased. Such changes have important consequences for species and landscape diversity. CJ Significant differences in insect and disease hazard severity were not detected at the river basin level due to high within-basin variability; however, some watershed hazards were substantially changed. The largest increases and decreases in specific insect or disease hazards indicate that these disturbance processes have been greatly altered by management. CJ Tree densities, fuel loads, fuel continuities, and fire hazards have increased in some watersheds, and decreased in others. The assessment analysis was not able to evaluate the contribution of green fuel ladders to fire hazards because appropriate fuel models were unavailable; however, these fuels may be one of the most important fire hazards on the eastside. CJ Riparian vegetation and associated fish habitats have been adversely affected in many watersheds by grazing, reading, irrigation, and flood control practices. (J Fire disturbance regimes have been altered through fire suppression especially on sites adapted to frequent, low and moderate severity fires.