Reconstructed Old-Growth Forest Stand Structure and Composition of Two Stands on the Olympic Peninsula, Washington State

Peter, David H.; Harrington, Constance A. 2010. Reconstructed old-growth forest stand structure and composition of two stands on the Olympic Peninsula, Washington state. Res. Pap. PNW-RP-583. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 22 p. We reconstructed the stand structure and composition for two western Washington old-growth forest stands harvested around 1930 (named Fresca and Rail) from field and historical data. Both old-growth stands had a codominant or dominant 250-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) overstory with a few scattered older Douglas-fir. Western hemlock (Tsuga heterophylla (Raf.) Sarg.) was codominant at Rail but was predominantly in the mid-story and understory at Fresca. The Fresca site is now dominated by Sitka spruce (Picea sitchensis (Bong.) Carr.) and western hemlock, whereas Rail has a composition similar to the previous old-growth stand. Events taking place early in succession are probably responsible for the differences between the modern and historical stands. Accelerated restoration of old-growth structural diversity may be possible at both sites through repeated creation of artificial gaps, but Fresca will remain different from its historical composition.