. A case study of a Douglas-fir tussock moth outbreak and stand conditions 10 years later. Douglas-fir tussock moth; Tree declines California; Trees Diseases and pests California. Table 9— Foliage condition of white fir by class 1967 and 1975 Foliage condition (in) Normal Thin No. % No. % 1967 1 c I -D ZZd A 0 45 1A Q 7-12 245 49 251 51 13-18 157 71 64 29 19-24 51 86 8 14 > 24 8 100 0 0 Total 686 55 566 45 1975 1-6 836 KJ ~J \J 97 22 ~J 7-12 433 99 4 1 13-18 255 100 0 0 19-24 83 100 0 0 > 24 32 100 0 0 Total 1,639 98 26 2 broken down into immediate, short-term pat- terns of
. A case study of a Douglas-fir tussock moth outbreak and stand conditions 10 years later. Douglas-fir tussock moth; Tree declines California; Trees Diseases and pests California. Table 9— Foliage condition of white fir by class 1967 and 1975 Foliage condition (in) Normal Thin No. % No. % 1967 1 c I -D ZZd A 0 45 1A Q 7-12 245 49 251 51 13-18 157 71 64 29 19-24 51 86 8 14 > 24 8 100 0 0 Total 686 55 566 45 1975 1-6 836 KJ ~J \J 97 22 ~J 7-12 433 99 4 1 13-18 255 100 0 0 19-24 83 100 0 0 > 24 32 100 0 0 Total 1,639 98 26 2 broken down into immediate, short-term pat- terns of growth reduction and 10-year post- outbreak effects. 7. Short-term patterns of reduction (im- mediate postoutbreak).—\r\ early spring 1965, 100 trees were given defoliation estimates, using the scheme of percent of crown lengths totally defoliated, reported for the Blue Mountains outbreak (Wickman 1978). In 1969, five of these trees were felled and destructively sampled with a disk cut at breast height, midcrown, and about 17 internodes from the terminal. The defoliation levels for each tree were: one tree, 50-percent, and four trees, 75-percent defoliated. Figure 4 shows the radial growth averages for these heavily defoliated trees. They all showed some growth reduction starting in 1964, a drastic reduction for the years 1965-67, and recovery to preoutbreak growth by 1969. Top and midcrown growth was reduced more than at 4- 3- o o < 2- a < Base Midcrown Top. 1959 60 61 —i 1 1 1 r— 62 63 64 65 66 YEAR 67 68 69 Figure 4.—Average radial growth at base, mid- crown, and top for five heavily defoli- ated white fir, Stowe Reservoir. 9. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Wickman, Boyd E. cn; Pacific Northwest Forest and Range Experiment Station (Portland, Or. ); United States. Forest S
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