Three harvest units adjacent to headwater streams were selected as study sites to investigate the efficacy of riparian silviculture and stream habitat improvement activities during and after timber harvesting to reset successional trajectories for riparian vegetation and aquatic habitat. The streams drained harvest regenerated forest stands, had limited large wood, and riparian areas were dominated by a hardwood overstory with a shrub understory. Active riparian area management included activities to establish and grow conifers in the riparian areas, i.e. riparian sliviculture, and to add large wood to the stream, i.e.stream habitat improvement. These activities took place during operational logging of the harvest units.

The experimental layout for the three study streams included creating three small openings adjacent to the stream; one was 600 feet long and the other two were each 300 feet long. In these openings all the overstory hardwoods were harvested or felled. Between the openings a standard buffer strip as required by the Oregon Forest Practice Rules was left. Within the openings, four species and several stocktypes of conifers were planted. Half of the planted areas were weeded and half were not. Also within the openings, large wood was added to the streams using the skyline yarder on site. Limbed and bucked conifer logs were placed in the streams using the yarder and it was also used to pull large, stream adjacent hardwoods into the stream complete with their root wads. Additional large wood was added to the streams during felling of stream adjacent hardwoods within the openings.

Time and motion studies were carried out during logging to determine the cost of using skyline logging equipment to place large wood in the stream. The survival and growth of the conifers planted in the stream-adjacent openings was determined. Stream temperature above and below the clear-cut openings was recorded to monitor the effect of the openings on water temperature. Large wood that was in the streams and was added to the streams was tagged and its location followed for three years after logging. High-resolution topographic maps of the streams channels were constructed annually to determine the effect that the added large wood had on physical habitat within the stream channels.

The time and motion studies showed that using the skyline yarder to place large wood in the stream was cost effective. the greatest cost associated with the stream habitat improvement activities was the species and quality of the wood added to the stream. Survival and growth of the conifer seedlings were variable however, Douglas-fir seedlings showed the best growth. Weeding was highly effective for survival and growth. Stream temperature increased as a result of the openings. Contemporary stream temperature models correctly predicted the temperature increases. The ability of the streams to propagate the stream temperature effects downstream was variable. After the winter, accumulations of large wood did develop in the streams and they were keyed on the large pieces of wood placed by the yarder. These debris accumulations improved the physical habitat for fish in the stream by increasing the volume and depth of residual pools and increasing cover.