Spruce budworm defoliation and growth loss in young balsam fir: artificial defoliation of potted trees

1990 ◽  
Vol 20 (7) ◽  
pp. 902-909 ◽  
Author(s):  
H. Piene ◽  
C.H.A. Little
Keyword(s):  
Specific Volume ◽  
Spruce Budworm ◽  
Experimental Period ◽  
Height Growth ◽  
Balsam Fir ◽  
Growth Responses ◽  
Volume Increment ◽  
Defoliation Treatment ◽  
Growth Loss ◽  
Foliage Weight

To simulate feeding by the spruce budworm (Choristoneurafumiferana Clem.), potted, 5-year-old balsam fir (Abiesbalsamea (L.) Mill.) trees were artificially defoliated at the peak of the sixth instar period in the first 1, 2, or 3 years of a 3-year experiment. This schedule allowed trees that were defoliated in the first 1 or 2 years to recover for 2 years and 1 year, respectively. Seven treatments were applied: 0, 33, 66, 90, or 100% of the current-year needles were manually removed, all current-year needles were clipped using scissors (clip treatment), or all current-year shoots were severed at their base (100+ treatment). The dry weights of stem axis, branch axes, and roots were measured at the end of the 3rd year, and current-year and total foliage weight, height growth, and specific volume increment were determined for each year of the experimental period. Needle removal decreased growth throughout the tree, the growth loss increasing with increasing intensity and frequency of defoliation. In the 1st year of defoliation, all treatments reduced specific volume increment, whereas only the 100+ treatment decreased height growth. In every defoliation year, specific volume increment, height growth (manifested in the year following the defoliation), and the final weights of stem axis, branch axes, and roots were generally related curvilinearly to total foliage weight. The 100% and 100+ treatments induced the sprouting of axillary and nodal buds that remained dormant in undefoliated trees. Retaining the defoliated shoot axes (100% treatment), compared with removing them (100+ treatment), increased specific volume increment. Retaining the needle base (clip treatment) prevented the apex necrosis that occurred in some shoots subjected to the 100% treatment. In trees allowed to recover, specific volume increment increased in the 1st year, the degree of recovery increasing with decreasing intensity and frequency of prior defoliation treatment. After 2 recovery years, specific volume increment and height growth were not affected by any previous defoliation treatment, and current-year foliage weight and stem axis weight were decreased only by the 100+ treatment; however, there was still an inhibitory effect of all treatments on the weights of total foliage, branch axes, and roots. The growth responses found in the present investigation were compared with those observed in balsam fir trees defoliated by the spruce budworm.

Spruce budworm defoliation and growth loss in young balsam fir: recovery of growth in spaced stands

1989 ◽  
Vol 19 (12) ◽  
pp. 1616-1624 ◽  
Author(s):  
Harald Piene
Keyword(s):  
Volume Growth ◽  
Spruce Budworm ◽  
Complete Recovery ◽  
Balsam Fir ◽  
Growth Recovery ◽  
Shoot Production ◽  
Volume Increment ◽  
Growth Loss ◽  
Major Factors ◽  
Foliar Biomass

Trees defoliated by the spruce budworm (Choristoneurafumiferana (Clem.)) for 1 to 4 years and subsequently protected rapidly regained foliar biomass. Three plots of 25- to 30-year-old balsam fir (Abiesbalsamga (L.) Mill.) trees, on the Cape Breton Highlands of Nova Scotia, were studied. Two major factors contributed to the rapid growth recovery rates: the ability to produce epicormic shoots, combined with increased retention of older age-classes of needles, and the development of new foliage at the expense of volume growth. A complete recovery of volume increment occurred after 2 years of extreme defoliation, but not after 4 years of severe defoliation. Epicormic shoot production was only associated with shoot and bud destruction and therefore, growth recovery was slow after partial defoliation of only current foliage. In all plots studied, there was a lag of 2 to 3 years between increased foliar biomass and significant increases in volume increment.

An evaluation of growth response of young, spaced balsam fir to 3 years of spruce budworm spraying with Bacillusthuringiensis

1984 ◽  
Vol 14 (3) ◽  
pp. 404-411 ◽  
Author(s):  
H. Piene ◽  
D. A. MacLean
Keyword(s):  
Growth Response ◽  
Tree Mortality ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Growth Responses ◽  
Average Volume ◽  
Cape Breton ◽  
Volume Increment ◽  
Total Gain

Growth response of young, spaced balsam fir (Abiesbalsamea (L.) Mill.) to 3 successive years (1979–1981) of treatment with Bacillusthuringiensis Berliner for spruce budworm (Choristoneurafumiferana (Clem.)) control was examined in 20 plots on the Cape Breton Highlands, Nova Scotia. Defoliation commenced in 1976, 3 years before control operations began. Five plots were established both inside and outside the spray block, in areas that had been severely defoliated by budworm and in areas moderately defoliated. All plots in the severely defoliated area suffered heavy tree mortality, but mortality was significantly lower in the protected plots. In contrast, the moderately defoliated plots suffered virtually no tree mortality. The average volume increment of stem-analyzed trees from 1979 to 1981 was 0.63 dm3/tree for protected and 0.43 dm3/tree for unprotected trees in the severely defoliated area versus 4.15 dm3/tree for protected and 3.08 dm3/tree for unprotected trees in the moderately defoliated area. These volume increment values are equivalent to 8.8 m3/ha of growth between 1979 and 1981 for protected plots in the moderately defoliated area, compared with 6.1 m3/ha for unprotected plots. Therefore, a total gain of 2.7 m3/ha can be attributed to the 3 years of B. thuringiensis spraying. Long-term growth responses toB. thuringiensis spraying were not evaluated. Better results would be expected had protection started at the beginning of the budworm outbreak, instead of after 3 years of severe defoliation.

The relation of balsam fir volume increment to cumulative spruce budworm defoliation

1996 ◽  
Vol 72 (5) ◽  
pp. 533-540 ◽  
Author(s):  
David A. MacLean ◽  
Eldon S. Eveleigh ◽  
Tony L. Hunt ◽  
Mervyn G. Morgan
Keyword(s):  
Specific Volume ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Regression Equations ◽  
Growth Reduction ◽  
Stem Analysis ◽  
Volume Increment ◽  
Mill Stand

The effect of cumulative defoliation caused by spruce budworm (Choristoneura fumiferana [Clem.]) from 1981 to 1987 on tree growth was assessed in a 35-year-old balsam fir (Abies balsamea [L.] Mill.) stand. After six years of moderate to severe defoliation, specific volume increment was reduced by an average of 11, 55, 83, 70, and 83% for trees with visual cumulative defoliation ratings, in 1987, of 1–25%, 26–50%, 51–75%, 76–90%, and 91–100%, respectively. Following defoliation, mean specific volume increment ranged from 0.02 cm3 cm−2 year−1 for trees with >90% cumulative defoliation to 0.16 cm3 cm−2 year for trees with <25% defoliation. Specific volume increment and percentage growth reduction were significantly related to the cumulative defoliation rating, with regression equations explaining 72 and 64%, respectively, of the variability among trees. It was concluded that onetime visual ratings of cumulative defoliation caused by spruce budworm can be used in assessing balsam fir growth rates and growth reduction. Key words: growth reduction, specific volume increment, stem analysis, Choristoneura fumiferana, Abies balsamea

Electrical resistance measurements on young balsam fir trees in relation to specific volume increment, foliar biomass, and ion content of bark and wood

1984 ◽  
Vol 14 (2) ◽  
pp. 177-180 ◽  
Author(s):  
H. Plene ◽  
R. G. Thompson ◽  
J. E. McIsaac ◽  
D. S. Fensom
Keyword(s):  
Electrical Resistance ◽  
Specific Volume ◽  
Balsam Fir ◽  
Ion Content ◽  
Volume Increment ◽  
Electrical Resistance Measurements ◽  
Foliar Biomass

Electrical resistance in young balsam fir (Abiesbalsamea (L.) Mill.) trees was inversely (nonlinear) correlated with specific volume increment, total foliar biomass, and the combined weight of the current and 1-year-old foliage. These relationships were stronger before budbreak than after. No relationship existed between concentrations of N, P, K, Ca, and Mg in the bark and wood collected around time of budbreak, and electrical resistance.

Growth loss and recovery following defoliation by the balsam fir sawfly in young, spaced balsam fir stands

2001 ◽  
Vol 133 (5) ◽  
pp. 675-686 ◽  
Author(s):  
Harald Piene ◽  
Don P. Ostaff ◽  
Eldon S. Eveleigh
Keyword(s):  
Volume Growth ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Recovery Rates ◽  
Wood Supply ◽  
Growth Recovery ◽  
Neodiprion Abietis ◽  
Volume Increment ◽  
Growth Loss ◽  
Intensively Managed

AbstractTwo stands of intensively managed balsam fir [Abies balsamea (L.) Mill. (Pinaceae)] in western Newfoundland, located within an area infested by the balsam fir sawfly, Neodiprion abietis (Harr.) (Hymenoptera: Diprionidae) complex, were selected to study growth loss and recovery following severe defoliation by the balsam fir sawfly in the early 1990s. Four years after the start of the outbreak, volume increments were reduced by 78–81%. The decreased volume increment and recovery coincided well with the balsam fir sawfly outbreak and decline. The growth recovery rates following severe balsam fir sawfly defoliation were slow due to the absence of bud destruction, which triggers the release of suppressed buds, and thus increases foliage production. It is imperative that the severe losses in volume growth caused by balsam fir sawfly defoliation are incorporated into wood supply analyses so that future annual allowable cuts may be adjusted. In addition, to ensure maximum recovery rates at the end of an outbreak, future populations must be kept at a minimum to avoid additional foliage loss.

Stochastic simulation of growth loss in thinned balsam fir stands defoliated by the spruce budworm in Newfoundland

1998 ◽  
Vol 28 (5) ◽  
pp. 703-710 ◽  
Author(s):  
Erhard John Dobesberger
Keyword(s):  
Stochastic Simulation ◽  
Larval Density ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Damage Function ◽  
Balsam Fir ◽  
Negative Exponential Function ◽  
Attack Pattern ◽  
Growth Loss ◽  
The Impact

A stochastic simulation model was developed to derive a damage function for the spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), and balsam fir, Abies balsamea (L.) Mill., herbivore interaction at the stand level for open-grown trees. Both aggregated and uniform models of attack pattern by late-instar larvae based on k of the negative binomial were evaluated to determine the impact of larval density and attack pattern on the loss in stemwood volume increment of young, thinned balsam fir stands in Newfoundland. Percentage loss in stemwood increment was a nonlinear, negative exponential function of initial larval density. Implementation of control measures to prevent 50% defoliation that is caused by about 14 larvae/branch tip would result in saving 24% of the annual stemwood increment after 1 year of defoliation and about 32% after 2 years of cumulative defoliation. Aggregation of spruce budworm larvae among trees within a forest stand results in less growth loss compared with a uniform pattern of attack. The nonlinear damage function may suggest tolerance and possibly compensatory growth after herbivory by low population levels of the spruce budworm.

Patterns of balsam fir foliar production and growth in relation to defoliation by spruce budworm

1995 ◽  
Vol 25 (7) ◽  
pp. 1128-1136 ◽  
Author(s):  
Donald P. Ostaff ◽  
David A. MacLean
Keyword(s):  
Spruce Budworm ◽  
Fold Increase ◽  
Balsam Fir ◽  
Radial Increment ◽  
Cape Breton Island ◽  
Cape Breton ◽  
Absolute Volume ◽  
Volume Increment ◽  
Previous Decade ◽  
Maximum Increment

Changes in foliar production caused by spruce budworm (Choristoneurafumiferana (Clem.)) defoliation and patterns of volume increment of surviving trees during and after the outbreak were determined in 20 mature balsam fir (Abiesbalsamea (L.) Mill.) stands on Cape Breton Island, Nova Scotia. Following the cessation of defoliation, the number of shoots increased 4-fold and mean shoot length doubled, resulting in a 12-fold increase in needle biomass. Average specific volume increment declined from 0.17–0.25 to 0.02–0.04 cm3•cm−2•year−1 after 4 years of severe defoliation; maximum increment reduction was 74–92%. Periodic radial increment and volume increment reduction (percent of mean increment in the previous decade) were both significantly related to cumulative (summed current annual) defoliation; a logistic regression equation explained 77% of the variation in volume loss. Differences in growth recovery among trees were determined by the temporal patterns of defoliation, with a 1-year lag before the beginning of volume increment recovery. Following 5 to 8 years of recovery, surviving trees had regained 48–82% of their predefoliation increment; however, absolute volume losses during the outbreak averaged 12–33 dm3/tree, or 32–48%.

Recovery of Young Balsam Fir Trees Damaged by Balsam Woolly Aphid

1976 ◽  
Vol 52 (3) ◽  
pp. 143-144 ◽  
Author(s):  
Hugh O. Schooley
Keyword(s):  
Height Growth ◽  
Balsam Fir ◽  
Normal Height ◽  
Woolly Aphid ◽  
Growth Loss ◽  
Terminal Buds

After one period of balsam woolly aphid damage, young balsam fir trees resumed normal height growth by the reactivation of inhibited terminal buds on 60% of trees, and by re-orientation of primary internodal and nodal branches on 24% and 16% of trees, respectively. Permanent forks and crooks were formed only infrequently. Height growth loss on damaged trees was small, equalling one to four years growth.

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