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Decay following pruning of Balsam fir in the Maritime Provinces of CanadaVan Sickle, Gordon Allan January 1969 (has links)
As management of forests and parks intensifies, pruning of
conifers becomes more common. Thus understanding the role of wounds
as possible entry courts for decay fungi is vital. In order to study
some aspects of this, three natural stands, one in New Brunswick and
two in Nova Scotia, which had been pruned 4 to 7 years earlier by
industrial or displaced workers, were examined. Five pruned and two
unpruned balsam fir (Abies balsamea (L.) Mill.) trees from each stand
were dissected; cultural isolations were taken from 207 knots where
pruning had caused little or no apparent damage to the bole, and from
169 blazes resulting from less careful prunings. All 15 pruned trees,
ranging in age from 23 to 42 years, had decay attributable to pruning
which averaged 1.7% of the stem volume. This incidence and volume of
decay exceeds that recorded in unpruned trees 40 to 60 years old in
New Brunswick.
Axe blazes were the major entry court for decay-causing fungis
basidiomycetes were associated with 12% of the blazes and with 5% of the
more carefully pruned knots. Neither stem nor butt decay was found in the
unpruned trees.
In a further study, 7 branches on each of 30 balsam fir trees
near Fredericton, N. B. were experimentally axe pruned; some carefully,
some carelessly; both during tree dormancy and during wet and dry periods of active growth. Thirty additional branches were saw pruned. At periods
of 2 to 3 weeks, 5 to 7 months and 17 to 19 months after pruning, cultures
were made in the field from 70 of the pruning wounds. Within 2 weeks of
the latter period, the trees were dissected, measured and further cultures
were made in the laboratory from the same 70 wounds.
Eighteen months after pruning, 28 of 30 trees had decay averaging
3.9% of stem volume and basidiomycetes were isolated from 22 (31%) of
70 wounds. In the controls butt decay only occurred in 4 of 10 trees.
These studies show: (l) that blazes into sapwood (careless
pruning) were more frequently infected than those where little or no
sapwood was exposed; (2) the incidence of infection was least in branches
pruned during the dry period and about equal for those pruned in the
wet-active and dormant periods; and (3) the successional pattern
began with imperfect fungi and bacteria, and terminated with decay fungi. / Forestry, Faculty of / Graduate
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Genetic variability of wound closure of street trees and effect of exogenously applied zinc/Martin, James Milton, January 1984 (has links)
No description available.
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Genetic variation and growth regulator effects on wound response among Acer and Populus taxa /Gallagher, Peter Wilmer, January 1982 (has links)
No description available.
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Assessing Forest Damage and Tree Response to Ice Storm Injury in Thinned and Unthinned Hardwood Stands in MaineSwisher, Julie Lee January 2001 (has links) (PDF)
No description available.
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Analysis of shear damage to southern pine lumberSwiatlo, Jeffrey A. January 1988 (has links)
This study was conducted as a second part in the shear damage research project at Virginia Tech. The objectives were to verify the results obtained by Gallagher (1984) in the first study under normal mill operations as well as develop a method to compare and evaluate the extent of shear damage in relation to other defects present in southern pine lumber. This was accomplished through two sawmill studies and two kiln cart surveys performed in different geographic locations.
Visible indicators such as stump-pull that are used to determine shear damage extent are often misleading. Stump-pull, used as a scaling deduction for shear damage, does not fully determine the extent of shear damage present. Shatter is often present in greater amounts over the cross section of the butt of the log. The recommendation of six inches of butt trim that was determined to minimize value losses in the first study is supported by the results obtained in this research. A trim of six inches removed 94 to 99 percent of shear damage in this study.
Defects other than shear damage were present on dried and surfaced lumber. Drying checks and splits along with shake were often observed on the lumber ends. These defects often extend further up on the lumber ends, past the seven inch simulated trim. Shake was determined to be the limiting defect. Shatter, in the absence of shake, was determined to be limiting.
Kiln cart surveys conducted at mills that utilize a large percentage of sheared logs can be an inexpensive and effective tool to enable mill personnel to determine the extent of shear damage in relation to other defects present on lumber ends based on green trim already taken. / Master of Science
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