. La défoliation et la mortalité dans les forêts du Connecticut. La défoliation des arbres feuillus ; ; ; les forêts et la foresterie. 20 40 60 80 100 1957 La surface terrière totale, de la SQ.FT./A 120 i.U 10 • ® © 0 4 3 20 40 60 80 100 120 1959 surface terrière totale, alors FT/A Fig. 5. La surface terrière périodique perte d'espèces majeures en parcelles avec la défoliation. Les sites sont comme dans la Fig. 2. La ligne est l'évolution de la surface terrière observée au cours de la perte dans le Meshomasic 1927-37 tracts. Partie supérieure. Série Meshomasic 1957-67. Uncircled nombres soient originaires de Turquie Hill défoliés en 1964. Les numéros sont encerclés de Cox, cabine et Reeves défoliés en 1961, 1962 et 1963.

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. Defoliation and mortality in Connecticut forests. Defoliation; Hardwoods; Trees; Forests and forestry. 20 40 60 80 100 1957 TOTAL BASAL AREA, SQ.FT./A 120 i.U 10 • ® © 0 4 3 20 40 60 80 100 120 1959 TOTAL BASAL AREA, SO FT/A Fig. 5. Periodic basal area loss of major species in tracts with defoliation. The sites are as in Fig. 2. The line is the trend of basal area loss observed during 1927-37 in the Meshomasic tracts. Upper. Meshomasic series 1957-67. Uncircled num- bers are from Turkey Hill defoliated in 1964. Circled numbers are from Cox, Cabin and Reeves defoliated in 1961, 1962 and 1963. Lower. Gay City 1959-70. Uncircled 4 is the dry site defoli- ated in 1962. Circled numbers are the moister sites defoliated in 1962 and 1967. Losses Among Canopy Trees Only the larger trees comprise the canopy of the forest. The examination of loss of basal area revealed that on the Meshomasic series some larger trees must have died. How serious are the losses? During a decade without defoliation, 1927-37, mortality of stems in the canopy of the Meshomasic tracts was less where the number of stems partici- pating in the canopy was less and the rela- tion was similar to that in Fig. 2, upper. On the other hand, loss of basal area was nearly constant regardless of total basal area of the trees in the canopy. During a later decade, 1957-67, losses on once-defoli- ated Turkey Hill were similar to the earlier period, but on Cox, Reeves and Cabin, defoli- ated three times, losses were greater both in number of stems and basal area. Average mor- tality of trees from undefoliated canopies was generally 1 percent or less and loss of basal area was less than 2 percent annually. After three consecutive defoliations average mortality of stems in the canopy ranged from 0.9 to 3.6 percent annually and loss of basal 30 r 20 u. ^ cr o < 5. 20 40 60 80 I00 I20 I40 I967 TOTAL BASAL AREA, SQ.FT./A cr o 5. Please note that these images are extracted from scanned page images that may have b

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