Schwartz Permanent Exclosures (Nos. 3-6,14-16, 19-23) J. E. Schwartz constructed 12 permanent exclosures from 1934 to 1936 in the Hoh, South Fork Hoh, Queets and Quinault river valleys. Two have never been relocated or sampled (Nos. 6, 20). The remaining 10 were either 0.09 ha (n=6) or 0.19 ha (n=4) and were constructed of split rails and barbed wire (n=8) or woven wire (n=2).Schwartz was concerned about the level of browsing on three species he considered "key browse species," salmonberry (Rubus spectabilis), vine maple (Acer circinatum), and huckleberry (Vaccinium parvifolium, and V. alaskense) (Schwartz 1939,Schwartz and Mitchell 1945, Schwartz pers.comm. 1990). Schwartz described vegetation by estimating "density of ground cover" on a scale of 1-10 in one (sometimes two) 9.3 mē plots inside exclosures. Estimates included only herbaceous species and omitted mosses. On different 9.3 mē plots he charted aerial cover of shrubs and also estimated percent cover of "grass" (including sedges), and "weeds" (i.e., forbs including ferns). Unfortunately only preliminary data from seven exclosures remain(Schwartz and Mitchell 1945).
Schwartz Takedown Exclosures (Nos. 7-12) Schwartz constructed six "takedown" exclosures in 1936 in addition to the permanent exclosures. These were designed to measure the effects of regulated browsing on vine maple (Nos. 7-9) and huckleberry (Nos. 10-12). The three exclosures forming each series were less than 50 meters from one another. The original objective was to allow wintering elk to browse shrubs to predetermined levels (25, 50, 75% utilization of annual production), close the exclosures and monitor shrub response (Schwartz 1939). All exclosures were opened in spring 1937 and closed permanently by 1938 (Schwartz 1990 pers. comm.). All data have been lost. C. C. Newman (1953) repaired six of the Schwartz exclosures and sampled vegetation inside and outside four in 1952 and 1955. Percent cover was estimated as <1% or as midpoints in 10 subsequent classes at 10% increments. Shrub stems were counted on 2.3 mē circular plots.
Newman Exclosures (Nos. 1, 2, 13, 17, 18) Newman constructed five variously sized exclosures of woven wire from 1953 to 1958. Three were in Sitka spruce stands in different river valleys (Bogachiel, No. 2; Hoh, No. 13; Queets, No.18), one in a red alder stand (Elwha, No.l) and one along an old-field/vine maple ecotone (Queets,No. 17). Three exclosures were established at particularly heavily grazed sites (Nos. 1, 13, 17). Apparently, No. 17 was to evaluate the ability of vine maple to recolonize an abandoned hayfield in the absence of browsing. No. 13 was built mainly to determine if vine maple and big leaf maple require mineral soil to reproduce from seed; one half of the exclosure and a corresponding outside plot were spaded in 1953. Percent cover by species was estimated on eight (four inside, four outside) 2.3 mē circular plots. Plots were established systematically, one in each quarter of the exclosure with a similar pattern (usually) outside. Data were collected by park personnel regularly through 1965 and again in 1982, although methods and seasons varied.
Olympic National Forest Exclosures (Nos. 24,25) Two 0.8 ha exclosures made of woven wire were established in 1957 on clearcut western hemlock/Pacific silver fir stands logged in 1955; both were essentially intact in 1990. Logging slash was left unburned at No. 24 and burned at No. 25. One-half of each exclosure was planted with 2-year old Douglas-fir (Pseudotsuga menziesii) seedlings and the other half was allowed to regenerate naturally. Mortality and growth rates were measured from 1957 to 1962 on 100 planted Douglas-fir seedlings inside and outside each exclosure (Harrison 1963). Species composition and cover of shrubs, grasses and forbs were measured inside No. 24 during 1957 (Brent 1957).
Recent Samples Schwartz Permanent Exclosures. We examined eight exclosures from 1986-1990; none was intact. Tree composition was sampled in six exclosures (Nos. 3, 14, 19, 21, 22, 23) using one or two 100-400 mē plots inside and outside (the two remaining sites had been altered by extensive treefall and were not sampled). Cover of large organic debris (LOD) was estimated and tree age was obtained for all individuals in each plot, either from increment cores taken close to the ground or basal sections of saplings 1-4 cm in diameter. Overstory cover was estimated overall and for each species to the nearest 10 percent. Inside and outside plots were comparable with respect to overstory composition and cover of LOD. Plots inside exclosures were placed a minimum of 2 m from fencelines, while outside plots were at least 10 m and usually much further from fencelines. Quinault River exclosures (Nos. 19-23) were sampled by Pfister and Pfister (1989) under our direction. Sampling focused on vine maple age and morphology in No. 4 (see takedown exclosures).
Schwartz Takedown Exclosures. We relocated the six takedown exclosures in 1990. While examining the vine maple series, we noticed that apically dominant stems originated either directly from the ground or from branches of older stems, and stem orientation varied from vertical to horizontal. Therefore, we measured age, stem length (rather than height above ground), number, diameter, and morphology (originating from branch or ground rooted) of stems > 1 cm. Samples were taken inside Nos. 7 and 9; we also included No. 4 (permanent) because vine maple density was comparable. Takedown No. 8 was not sampled because vine maple was sparse. Plot sizes ranged from 9.5 x 14.3 m to 20 x 20 m for a total area of 675 mē inside and 850 mē outside. Because exclosures were placed specifically around clumps of vine maple, we deliberately established outside plots in stands having comparable composition and stem density. We measured dimensions of huckleberry clumps (stems arising from a common root crown) in 8.5 x 14 m plots inside and outside Nos. 11and 12. Exclosure 10 was omitted because huckleberry was uncommon. Outside plots were chosen which had huckleberry-dominated shrub layers, and overstory types, slopes, aspects and geomorphic surfaces similar to the exclosures. We counted the number of stems and measured height of the tallest stem, length and width of each clump. Canopy area was computed as an ellipse from the length and width. Several of the largest stems at each site were cut for determining age.
Newman Exclosures. We examined all five Newman sites from 1987-1990; two exclosures were intact (Nos. 1 and 2). We measured cover of shrubs(1 x 4 m plots) and herbaceous species (1 x 1 m plots) in classes of <1, 1-5, 6-25, 26-50, 51-75,76-95, and 96-100%. Fourteen subplots were placed in a single 8 x 20 m macro plot inside exclosures and distributed seven each in two 8 x 20m macro plots outside. As with the Schwartz exclosures, cover of LOD was measured, and ages of all trees >1 cm in diameter at the base were determined from cores or basal disks.
Olympic National Forest Exclosures. We sampled species composition, age and growth (i.e., dbh and height) of trees on two (burned, No. 25) or three (unburned, No. 25) 225 mē plots inside and out of each exclosure. We sampled the unplanted site at No. 25 and the planted site at No. 24. We avoided sampling other sites because vegetation heterogeneity prevented us from locating paired plots in and out of exclosures.
Photographs. In addition to sampling vegetation, we examined historic photographs. We located 48 photos of Schwartz exclosures from construction through 1980, 349 photos or slides of Newman exclosures, and 2 photos of the Forest Service exclosures.