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Intact riparian ecosystems are rich in biological diversity, but throughout the world, many have been degraded. Biodiversity declines, particularly of vertebrates, have led to experimental efforts to restore riparian forests by thinning young stands to accelerate creation of large diameter live trees. However, many vertebrates depend on large diameter deadwood that is standing as snags or fallen to the forest floor or fallen into streams. Therefore, we reviewed the sizes of deadwood and live trees used by different vertebrate species to understand which species are likely to benefit from different thinning treatments. We then examined how riparian thinning affects the long-term development of both large diameter live trees and deadwood. To this end, we used a forest growth model to examine how different forest thinning intensities might affect the long-term production and abundance of live trees and deadwood. Our results suggest that there are long-term habitat tradeoffs associated with different thinning intensities. Species that utilize large diameter live trees will benefit most from heavy thinning, whereas species that utilize large diameter deadwood will benefit most from light or no thinning. Because far more vertebrate species utilize large deadwood rather than large live trees, allowing riparian forests to naturally develop may result in the most rapid and sustained development of structural features important to most terrestrial and aquatic vertebrates.

Pollock, Michael M. and Timothy J. Beechie, 2010. Reply to Discussion –“Stream Temperature Relationships to Forest Harvest in Western Washington” by George Ice, George Brown, John Gravelle, C. Rhett Jackson, Jeff Light, Timothy Link, Douglas Martin, Dale McGreer, and Arne Skaugset. Journal of the American Water Resources Association (JAWRA) 46(4): 843-847. DOI: 10.1111/j.1752-1688.2010.00456.x

We compared summer stream temperature patterns in 40 small forested watersheds in the Hoh and Clearwater basins in the western Olympic Peninsula, Washington, to examine correlations between previ- ous riparian and basin-wide timber harvest activity and stream temperatures. Seven watersheds were unhar- vested, while the remaining 33 had between 25% and 100% of the total basin harvested, mostly within the last 40 years. Mean daily maximum temperatures were significantly different between the harvested and unhar- vested basins, averaging 14.5� C and 12.1� C, respectively. Diurnal fluctuations between harvested and unhar- vested basins were also significantly different, averaging 1.7� C and 0.9� C, respectively. Total basin harvest was correlated with average daily maximum temperature (r 2 = 0.39), as was total riparian harvest (r 2 = 0.32). The amount of recently clear-cut riparian forest ( 75% harvest met DOEs water quality standard. Many streams with extensive canopy closure, as estimated by the age of riparian trees, still had higher temperatures and greater diurnal fluctuations than the unharvested basins. This suggests that the impact of past forest harvest activities on stream temperatures cannot be entirely mitigated through the reestablishment of riparian buffers. (KEY TERMS: riparian ecology; fluvial processes; streamflow; land use ⁄land cover change; temperature; watershed management.)