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APPENDIX A Methods for Sampling and Analysis of Red Spruce Data Red spruce were surveyed during the summer of 1982 at 11 sites in New Hampshire, Vermont, New York, West Virginia, Virginia, and North Carolina. The northern sites were emphasized. Mount Washington, Mount Mansfield, and Whiteface Mountain were selected because they had operating weather stations at their summits. The sites in the southern Appalachians were selected as typical stands through consultation with local foresters. Hunter and Plateau mountains in the Catskill Mountains (New York) were selected on the basis of the stand descrip- tions of McIntosh and Hurley (1964). Transects were established with an altimeter at arbitrary elevations on east- and west-facing slopes. On Mount Washington, Mount Mansfield, and Whiteface Mountain, transects 100 m long were established parallel to eleva- tional contours at 50-m intervals through the spruce-fir, transition, and hardwood forests. The elevations of the transects generally ranged from 1100 to 650 m. The elevation of a given transect was adjusted if topographic conditions so dictated. At the other sites an arbitrary elevation judged to be representative of the stand was selected and a transect 600 m long was established. Sampling along the transects was designed to meet three major objectives: (1) to rate the extent of deterioration of spruce in the canopy, (2) to determine the percentage of dead spruce across a variety of size classes, and (3) to obtain increment cores to determine canopy age and for tree ring analysis. To determine the extent of deterioration of spruce in the canopy, sampling points were established at 2s-m intervals by tape if practical, or by pacing. The nearest spruce greater than 10-cm diameter breast height (dbh) in the canopy in each quadrant around the sampling 435

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436 point was rated using a four-point scale as follows: 1, little or no loss of foliage in the upper crown. 2, loss of foliage from the top of the crown and/or some loss of foliage on the outer tips of live branches; total loss of foliage from the upper portion of the crown less than 50 percent. 3, loss of foliage and dieback of the upper crown greater than 50 percent. 4, dead. A zero was recorded if there were no red spruce in a quadrant within an arbitrary distance of the sampling point (usually 12.5 m). At lower elevations in hardwood dominated forests, the sampling intervals were extended in some locations so as to include a reasonable number of spruce. Results are recorded in Table A.1. At each sampling point, the nearest live red spruce greater than 10-cm dbh in the canopy was cored to estimate canopy ages. Two cores per tree were extracted at 1.2 m above ground surface, parallel to the topographic contours. At each cored tree an estimate of stand basal area was made using a wedge prism (basal area factor = metric 2.5). This estimate has a slight positive bias, as the sampling point was always located within 1 m of a cored tree. species, dbh, and live/dead status of each stem in the prism were recorded and used to estimate the percentage of live and dead red spruce in each dbh class. To get a sample of dominant trees for tree ring analyses, stands between 800 and 950 m were sampled for red spruce and balsam fir. (See Figures 6.8 to 6.10.) A subset of cores was collected from trees that were in class 1 or 2, had no sign of past injury, and were taller than the neighboring trees. This subset included some cored trees from the intermediate elevation transects as well as spruce from nearby if all spruce at the sampling point were class 3 or 4. Occasionally class 3 trees were sampled if they were the only ones available. Fifteen trees (two cores per tree) that cross-dated well were used for the analyses. This sample is biased in favor of more vigorous trees. Tree ring index chronologies shown in Figures 6.8 to 6.10 were produced by D. Duvick and T. J. Blasing at Oak Ridge National Laboratories for the Forest Response to Anthropogenic Stress (FORAST) program (McLaughlin et al. 1983). We gratefully acknowledge their contributions. Measured cores were cross-dated with a skeleton-plot technique (Stokes and Smiley 1968) to assure accurate determination of the date of each ring measured. The time series of annual growth measurements for any given core will typically contain two types of variation: come ~ oss off

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437 TABLE A. 1 Determination of the Extent of Deterioration in Red Spruce at Selected Sites in the Eastern United States c' c' cq 0 ~ ~ ~ ~ ~ ~ _ ~ O ~ ~ ~ ~ ~ ~ ~ v: ~ ~ ~ ~ ~ ~ ~ ~ 0 0 ~ ~ ~ ~ ~ =.> Site Name Z Mt. Washington, East 017 65 12 18 06 1120 50 019 42 00 32 26 1060 38 019 53 05 16 26 1000 42 020 50 15 20 15 0950 34 020 25 15 35 25 0900 39 019 53 26 11 11 0850 32 018 28 22 22 28 0800 34 016 50 19 12 19 0750 33 017 41 12 00 47 0700 32 020 55 30 05 10 0650 34 Mt. Washington, West 020 25 25 30 20 1150 36 020 15 35 30 20 1100 40 020 35 10 35 20 1050 39 020 15 25 40 20 1000 37 020 55 15 15 15 0950 32 020 45 15 20 20 0900 37 020 40 15 05 40 0850 42 020 60 20 00 20 0800 34 020 60 15 10 15 0750 32 020 60 20 00 20 0700 36 Mt. Mansfield, East 015 07 07 47 40 1120 26 019 37 05 37 21 1060 30 020 20 15 25 40 1000 31 017 12 18 29 41 0950 25 008 50 00 12 38 0900 29 016 38 25 12 25 0850 24 018 28 28 00 44 0800 29 013 46 15 15 23 0750 26 013 54 15 08 23 0700 28 012 75 08 00 17 0650 24 Mt. Mansfield, West 020 20 10 35 35 1050 18 018 11 22 45 22 1000 26

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438 TABLE A.1 (continued) c; u' con C: _ 0 ~ ~ _` ~ ;> en - , con ~ ~ ~ ~ c,) O con 'A c.> Site Name Z ~ ~ ~ ~ ~ m Mt. Mansfield, West 020 35 05 25 35 0950 22 019 26 21 05 47 0900 30 020 25 20 15 40 0850 32 020 35 25 15 25 0800 24 Whiteface Mtn., East 020 10 10 45 35 1110 28 019 16 42 26 16 1060 31 017 24 47 18 12 1000 42 018 56 28 00 17 0950 30 014 50 29 14 07 0900 28 014 00 79 00 21 0850 41 019 00 63 21 16 0800 40 016 38 56 00 06 0750 33 020 50 35 05 10 0700 30 020 45 40 10 05 0650 27 Whiteface Mtn., West 019 26 21 21 32 1220 34 020 00 20 40 40 1150 34 014 14 14 29 43 1070 34 020 25 20 25 30 1000 36 018 28 44 00 28 0950 42 017 47 24 06 24 0910 38 020 70 10 10 10 0850 52 019 68 26 00 05 0780 40 018 56 17 00 28 0720 40 020 75 15 00 10 0670 34 Hunter Mtn. 092 48 21 11 20 1052 30 Plateau Mtn. 100 63 20 07 10 1128 35 Shenandoah Natl. Pk. 088 72 08 00 20 1005 40 G. Washington Natl. For. 100 89 07 00 04 1128 32 Monongahela Natl. For. 100 69 10 02 19 1311 48 Whitetop Mtn. 100 84 10 02 04 1524 37 Roan Mtn. 093 83 04 01 12 1768 35 Mt. Mitchell 082 91 04 01 04 1615 36

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439 (1) high-frequency variance owing to the influence of factors over time intervals of a year or a few years and (2) low-frequency variance caused by longer-term fluctua- tions involving factors, such as tree age or stand development, or long-term climatic changes that have periods of influence typically extending over several years or decades. To describe the low-frequency varia- tions in growth over the tree's life cycle, cubic spline functions (Biasing et al. 1983, Cook and Peters 1981) were fitted to the ring-width series of each tree over discrete time intervals (i.e., before and after a sudden major release from competition after a known major dis- turbance such as logging). A spline statistically delineates a weighted moving average of growth over the specified time interval. Dividing each ring-width value by the corresponding value of the spline function produces a series of ring-width indices (Fritts et al. 1971, Fritts 1976, Blasing et al. 1983) that have a mean of 1.0 and a variance that is approximately constant through time. The filtering characteristics of the spline were chosen to remove low-frequency variance characteristic of the slow changes in competitive status and tree age but to preserve intermediate- and high-frequency variance (Nash et al. 1975, Blasing et al. 1983). REFERENCES Blasing, T. J., D. N. Duvick, and E. R. Cook. 1983. Filtering the effects of competition from ring width series. Tree Ring Bull. 43:19-30. Cook, E. R., and K. Peters. 1981. The smoothing spline: A new approach to standardizing forest interior tree-ring width series for dendroclimatic studies. Tree Ring Bull. 41:45-54. Fritts, H. C. 1976. Tree Rings and Climate. London: Academic Press. Fritts, H. C., T. J. Blasing, P. B. Hayden, and J. E. Kutzbach. 1971. Multivariate techniques for specifying tree-growth and climate relationships and for reconstructing anomalies in paleoclimate. J. Appl. Meteorol. 10:845-864. McIntosh, R. P., and R. T. Hurley. 1964. The spruce-fir forests of the Catskill Mountains. Ecology 45:314-326

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440 McLaughlin, S. B., T. J. Blasing, L. H. Mann, and D. N. Duvick. 1983. Effects of acid rain and gaseous pollutants on forest productivity. J. Air Pollut. Control Assoc. 33:1042-1048. Nash, T. III, H. C. Fritts, and M. A. Stokes. 1975. A technique for examining non-climatic variation in widths of annual tree rings with special reference to air pollution. Tree Ring Bull. 35:14-20. Stokes, M. A., and T. L. Smiley. 1968. An Introduction to Tree Ring Dating. Chicago: University of Chicago Press.