Spruce budworm defoliation and growth loss in young balsam fir: defoliation in spaced and unspaced stands and individual tree survival

1989 ◽  
Vol 19 (10) ◽  
pp. 1211-1217 ◽  
Author(s):  
Harald Piene
Keyword(s):  
Tree Mortality ◽  
Spruce Budworm ◽  
Shoot Elongation ◽  
Balsam Fir ◽  
Individual Tree ◽  
Cape Breton ◽  
Tree Survival ◽  
Growth Loss ◽  
Individual Trees ◽  
Foliar Biomass

A severe outbreak of spruce budworm (Choristoneurafumiferana (Clem.)) began in 1976 in young, spaced and unspaced stands of balsam fir (Abiesbalsamea (L.) Mill.) located on the Cape Breton Highlands, Nova Scotia, Canada. A study was initiated that year to relate decreases in foliar biomass, caused by defoliation, to reductions in annual volume increment. Detailed defoliation assessments on individual trees from 1976 to 1984 showed severe defoliation of the current foliage in 1976. In 1977 and 1978, current foliage was destroyed in the early part of shoot elongation and severe back-feeding occurred on older age-class needles. After 1978, defoliation decreased as a result of a decline in budworm populations and, in general, only the current foliage was defoliated until the populations decreased to low levels in 1983. Defoliation was significantly higher in spaced than in unspaced stands in 1977, 1978, and 1980, and as a result, by 1984, average tree mortality caused by spruce budworm was 43.8% in spaced and 18.9%.in unspaced stands. The survival of some balsam fir trees and not others following a budworm outbreak is not related to differential defoliation, but to the ability of some balsam fir trees to rapidly increase foliar biomass through prolific epicormic shoot growth.

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.

Patterns of balsam fir mortality caused by an uncontrolled spruce budworm outbreak

1989 ◽  
Vol 19 (9) ◽  
pp. 1087-1095 ◽  
Author(s):  
David A. MacLean ◽  
Donald P. Ostaff
Keyword(s):  
Tree Mortality ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Regression Equations ◽  
Cape Breton Island ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Cape Breton ◽  
Dead Trees ◽  
Site Characteristics

Tree mortality caused by spruce budworm (Choristoneurafumiferana (Clem.)) defoliation was assessed annually from 1976 to 1985 in 20 mature balsam fir (Abiesbalsamea (L.) Mill.) stands on Cape Breton Island, Nova Scotia, and was related to defoliation and to tree, stand, and site characteristics. Ten to 12 years after the start of the budworm outbreak, fir mortality averaged 87% of the merchantable volume (range 60–100%) among the stands. Timing of mortality was similar to that found in studies of previous outbreaks. In the first 4 years of the outbreak, virtually all the trees that died had more than 90% cumulative defoliation but, overall, 64, 21, and 14% of the dead trees had cumulative defoliation >90, 76 to 90, and 51 to 75%, respectively. Early in the outbreak, fir mortality was generally negatively correlated with tree vigor, relative crown position, or diameter at breast height, but in later years, trees were killed irrespective of these factors. Fir mortality was evenly distributed among different sized trees, and 73 to 86% of the trees in each 5 cm diameter at breast height class died. A linear regression equation between dead fir volume and total fir volume explained 89% of the variability in mortality among stands. Percent fir mortality was correlated (r = 0.84) with visual estimates of cumulative defoliation (including all age-classes of foliage) in 1981, but mortality was not correlated with cumulative current annual defoliation or with site characteristics. Using regression equations, fir mortality during this budworm outbreak was predicted to within ±6 m2/ha in 14 of 18 (78%) of the stands, with a relative accuracy of 17.7%.

scholarly journals Spruce Budworm Defoliation and Growth Loss in Young Balsam Fir: Estimation of Volume Growth Based on Stem Analysis and Increment Cores at Breast Height

1996 ◽  
Vol 13 (2) ◽  
pp. 73-78 ◽  
Author(s):  
Harald Piene ◽  
Janine D'Amours ◽  
Alan A. Bray
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Stem Analysis ◽  
Individual Tree ◽  
Breast Height ◽  
Individual Tree Growth ◽  
Growth Loss ◽  
Changes Over Time

Abstract Comparisons of estimates of volume and volume increment, based on increment cores sampled at breast height and on stem analysis, were made in a young balsam fir stand that had been defoliated by spruce budworm. Use of increment cores is not recommended to estimate individual tree growth, because large errors, ranging from 20.9 to 57.2%, and error variability can be expected. The inability, when using increment cores, to estimate basal area is the major source of this variation. Although large uncertainties are associated with future growth predictions, on a per ha basis, changes over time based on increment cores may in some instances give comparable results to those based on stem analysis due to the canceling effect of trees being approximately equally overestimated and underestimated. However, a prerequisite is that the defoliation history and the year of individual tree death are known in detail to aid in the correct dating of ring widths. North. J. Appl. For. 13(2):73-78.

Spruce budworm populations, defoliation, and changes in stand condition during an uncontrolled spruce budworm outbreak on Cape Breton Island, Nova Scotia

1989 ◽  
Vol 19 (9) ◽  
pp. 1077-1086 ◽  
Author(s):  
Donald P. Ostaff ◽  
David A. MacLean
Keyword(s):  
Nova Scotia ◽  
Tree Mortality ◽  
Total Mortality ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Cape Breton Island ◽  
Cape Breton ◽  
Dead Trees ◽  
Spruce Mortality ◽  
Third Instar Larvae

Effects of an uncontrolled spruce budworm (Choristoneurafumiferana (Clem.)) outbreak in 20 mature balsam fir (Abiesbalsamea (L.) Mill.) stands on Cape Breton Island, Nova Scotia, were studied from 1976 to 1985. Spruce budworm populations were extremely high, higher than peak levels recorded for other outbreaks, and averaged over 380 third-instar larvae per square metre of foliage from 1976 to 1980. As many as 1570 third-instar larvae per square metre occurred 5 to 7 years after the start of the outbreak, resulting in complete current defoliation and back-feeding on older foliage. Stands were divided into three groups, based on the pattern of cumulative current defoliation; the sum of current annual defoliation during the outbreak was 343, 445, and 543% for these groups, equivalent to the removal of 3.5 to 5.5 age-classes of foliage. Budworm defoliation caused the death of 78, 80, and 89% of the merchantable balsam fir volume in the three groups of stands, respectively, as well as 27% of the spruce (Picea sp.) volume; another 39% of the spruce volume died as a result of spruce beetle (Dendroctonusrufipennis Kby.) activity. Fir mortality commenced 3 years after the start of the outbreak and spruce mortality 2 to 3 years later. About one-half of the total mortality occurred in the 4 years after budworm populations and defoliation returned to low levels. Tree mortality and loss of foliage opened the stands, and 4 years after the collapse of the outbreak, 4% of the surviving trees and 17% of the dead trees had blown down, whereas 60% of all trees had broken tops.

CHANGES IN SPRUCE BUDWORM DEFOLIATION WITH CROWN LEVEL

1996 ◽  
Vol 128 (6) ◽  
pp. 1109-1113 ◽  
Author(s):  
Harald Piene
Keyword(s):  
Nova Scotia ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Cost Effective ◽  
Balsam Fir ◽  
Crown Length ◽  
Cape Breton ◽  
Cost Effective Approach ◽  
The Common

AbstractDetailed estimates of defoliation caused by spruce budworm [Choristoneura fumiferana (Clem.)] over the crown length of young balsam fir [Abies balsamea (L.) Mill.] were made throughout a spruce budworm outbreak from 1976 to 1984 in the Cape Breton Highlands, Nova Scotia. The results show no clear tendency for a particular level of the crown to be damaged more heavily than any other. Thus, there is no reason to continue the common practice of taking samples from the mid-crown level on the assumption that they represent an ‘average’ level of defoliation either for high or low populations. Sampling from the bottom of the crown should provide a more convenient and cost-effective approach for estimating defoliation.

A Biodegradable Formulation of MCH (3-Methylcyclohex-2-en-1-one) for Protecting Pseudotsuga menziesii from Dendroctonus pseudotsugae (Coleoptera: Curculionidae) Colonization

2020 ◽  
Vol 113 (4) ◽  
pp. 1858-1863 ◽  
Author(s):  
Gabriel G Foote ◽  
Christopher J Fettig ◽  
Darrell W Ross ◽  
Justin B Runyon ◽  
Tom W Coleman ◽  
...  
Keyword(s):  
New Mexico ◽  
Pseudotsuga Menziesii ◽  
Tree Mortality ◽  
Douglas Fir ◽  
Dendroctonus Pseudotsugae ◽  
Individual Tree ◽  
Significant Difference ◽  
Antiaggregation Pheromone ◽  
Individual Trees

Abstract Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, trees and stands can be protected from Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (DFB)-caused mortality by application of synthetic formulations of the beetle’s antiaggregation pheromone, 3-methylcyclohex-2-en-1-one (MCH). A biodegradable formulation of MCH, SPLAT MCH, was developed and evaluated for protecting individual Douglas-fir trees and small stands from colonization and mortality by DFB. In an individual-tree experiment in Idaho, both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of treated trees colonized and killed by DFB compared to untreated controls. SPLAT MCH was as effective as MCH bubble capsules for protecting individual trees. Both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of trees colonized and killed by DFB within 0.04-ha circular plots surrounding each treated tree compared to untreated controls. In 0.41 ha stands in New Mexico, both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of trees colonized and killed by DFB compared to untreated controls, again with no differences observed between MCH treatments. In a similar stand level trial in Idaho, neither MCH treatment significantly reduced the proportion of trees colonized by DFB, and only MCH bubble capsules significantly reduced levels of tree mortality compared to untreated controls, but no significant difference was observed between SPLAT MCH and MCH bubble capsules. Overall, the results indicate that SPLAT MCH is as effective as MCH bubble capsules for protecting individual trees and small stands of Douglas-fir from DFB-caused mortality.

Spatial and temporal patterns of balsam fir mortality in spaced and unspaced stands caused by spruce budworm defoliation

1995 ◽  
Vol 25 (6) ◽  
pp. 902-911 ◽  
Author(s):  
David A. MacLean ◽  
Harald Piene
Keyword(s):  
Temporal Patterns ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Feeding Damage ◽  
Spatial And Temporal Patterns ◽  
Cape Breton Island ◽  
Plot Size ◽  
Cape Breton ◽  
Significant Difference ◽  
Percent Mortality

Spatial and temporal patterns of balsam fir (Abiesbalsamea (L.) Mill.) mortality were studied during a spruce budworm (Choristoneurafumiferana Clem.) outbreak from 1976 to 1984 on Cape Breton Island, Nova Scotia. Natural mortality in four insecticide-protected plots was 0% in spaced and 9–15% in unspaced stands, with only the smallest trees dying. Budworm-caused mortality (i.e., total minus natural) was 31–49% and 11–32% in spaced and unspaced young fir plots, respectively, but reached 94–100% in severely defoliated spaced plots, unprecedented in the literature for young fir mortality caused by the spruce budworm. Mortality began in the fourth to sixth year of defoliation, being earliest in the severely defoliated plots. From 80 to 90% of trees that died had > 75% cumulative defoliation, and most (64–100%) of the smallest (2 cm DBH) trees died. There was no significant difference in percent mortality between 25 spaced and 13 unspaced plots (p = 0.434), although, on average, mortality was 10–22% higher in the spaced plots. About 20–30% more of the intermediate-sized and largest trees were killed in the spaced plots. High spatial plot to plot variability in mortality occurred, which was apparently related to observed differences in the amount of defoliation and especially the incidence of "back-feeding" (damage to noncurrent foliage), as well as to plot size. Because budworm-caused mortality exhibits a distribution that tends to form large "holes" in stands, the degree of between-plot variability is related to plot size, and it is recommended that small plots that may miss these patches of mortality be avoided.

scholarly journals THE VULNERABILITY OF BALSAM FIR TO SPRUCE BUDWORM ATTACK IN NORTHWESTERN ONTARIO, WITH SPECIAL REFERENCE TO THE PHYSIOLOGICAL AGE OF THE TREE

1958 ◽  
Vol 34 (4) ◽  
pp. 405-422 ◽  
Author(s):  
J. R. Blais
Keyword(s):  
Special Reference ◽  
Tree Mortality ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Site Quality ◽  
Physiological Age ◽  
Northwestern Ontario ◽  
Relationship Of ◽  
The Relationship ◽  
Relative Vulnerability

The annual defoliation by spruce budworm and the progressive mortality of balsam fir trees were recorded in nine study plots in northwestern Ontario over a period of 11 years. In addition to general observations on the relationship of tree mortality to defoliation, some information was obtained on the relative vulnerability of the trees with respect to size, physiological age (flowering condition), and vigor (site quality).

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.

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