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Live trees, standing dead trees, and downed logs have been retained in some forest harvest sites in the Pacific Northwest to fulfill various ecological objectives. To assess the fates of retained trees following partial cutting of mature forests in the central western Cascade Range in Oregon, we inventoried standing live and dead trees and toppled trees in 21 cutting units in 1993 and 2001. In 1993, 1–10 years after cutting, an average of 65% of the initially retained trees (average of counts for all sites) were alive and standing, 12% had been toppled or topped by wind, 13% had become snags by natural processes, and 10% were converted to snags by management action, including cutting, blasting, girdling, and inoculation with fungi. By 2001, when cutting-unit ages ranged from 9 to 18 years, 54% of the retained trees were alive and standing, 10%–21% had been toppled or topped by wind, 11%–22% had become snags by natural processes, and 14% had been converted to snags by management action. The highest levels of mortality occurred at sites with abundant intentional snag creation and (or) prescribed fire following harvest. The rate of mortality due to windthrow declined over time, possibly because the remaining trees were more windfirm. [ABSTRACT FROM AUTHOR]

Although headwater streams constitute a significant portion of stream length within watersheds, their aquatic fauna, contributions to regional biodiversity, and responses to forest management have been understudied. Macroinvertebrate communities, physical habitat, and water chemistry were sampled from 40 headwater streams in managed forests in the Oregon Coast Range mountains. We characterized functional and structural attributes of macroinvertebrate communities in relation to physical, chemical, and biological gradients. Substrate composition, specific conductance, and riparian forest age showed the strongest correlations with resultant ordination patterns in macroinvertebrate community composition. Among individual metrics of community structure and composition, total macroinvertebrate density and dominance by three taxa showed the strongest correlations with forest age. No community measures were related to densities of torrent salamanders (Rhyacotriton kezeri) or crayfish (Pacifastacus leniusculus), suggesting these potential predators had little influence on overall macroinvertebrate community structure. Rare taxa were sampled from several reaches, including Rhyacophila probably viquaea for which little information is available, and an Eobrachycentrus sp., previously known to occur only in the Cascade mountains. Headwater streams within these managed forests of northwestern Oregon appear to be taxa rich, continue to support taxa limited to headwater streams, and harbor taxa about which little is known. [ABSTRACT FROM AUTHOR]