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

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.

2011 ◽  
Vol 28 (2) ◽  
pp. 72-78 ◽  
Author(s):  
Anthony W. D'Amato ◽  
Stacy J. Troumbly ◽  
Michael R. Saunders ◽  
Klaus J. Puettmann ◽  
Michael A. Albers

Abstract The effects of thinning treatments on growth and survivorship of white spruce (Picea glauca [Moench] Voss) plantations affected by recent eastern spruce budworm (SBW) outbreaks were examined over a 5-year period in northern Minnesota. Thinning treatments increased individual tree growth, live crown ratios (LCRs), and survival relative to unthinned stands. Overall, stands affected by SBW had lower rates of volume production than unaffected stands. In addition, individual tree volume growth was greater in thinned SBW-affected stands relative to unthinned SBW-affected stands. Across stand conditions, individual tree postthinning volume growth response was best predicted by the interaction of prethinning LCR and postthinning relative density (RD). In particular, at low stocking levels (RD = 0.20) higher live crown values resulted in the highest volume growth ratios. On the other hand, at higher stocking levels (RD 0.40–0.55) volume growth was fairly consistent, regardless of LCRs. Across all stocking levels, a minimum LCR of 40% appears to ensure high tree and stand growth rates and is also an indicator of a tree's ability to respond positively to thinning. This plasticity of white spruce suggests that stands maintained at these crown target levels can achieve high levels of stand and individual tree productivity as long as appropriate LCRs are maintained.


Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 232 ◽  
Author(s):  
Mingke Li ◽  
David MacLean ◽  
Chris Hennigar ◽  
Jae Ogilvie

We investigated the spatial-temporal patterns of spruce budworm (Choristoneura fumiferana (Clem.); SBW) defoliation within 57 plots over 5 years during the current SBW outbreak in Québec. Although spatial-temporal variability of SBW defoliation has been studied at several scales, the spatial dependence between individual defoliated trees within a plot has not been quantified, and effects of defoliation level of neighboring trees have not been addressed. We used spatial autocorrelation analyses to determine patterns of defoliation of trees (clustered, dispersed, or random) for plots and for individual trees. From 28% to 47% of plots had significantly clustered defoliation during the 5 years. Plots with clustered defoliation generally had higher mean defoliation per plot and higher deviation of defoliation. At the individual-tree-level, we determined ‘hot spot trees’ (highly defoliated trees surrounded by other highly defoliated trees) and ‘cold spot trees’ (lightly defoliated trees surrounded by other lightly defoliated trees) within each plot using local Getis-Ord Gi* analysis. Results revealed that 11 to 27 plots had hot spot trees and 27% to 64% of them had mean defoliation <25%, while plots with 75% to 100% defoliation had either cold spot trees or non-significant spots, which suggested that whether defoliation was high or low enough to be a hot or cold spot depended on the defoliation level of the entire plot. We fitted individual-tree balsam fir defoliation regression models as a function of plot and surrounding tree characteristics (using search radii of 3–5 m). The best model contained plot average balsam fir defoliation and subject tree basal area, and these two variables explained 80% of the variance, which was 2% to 5% higher than the variability explained by the neighboring tree defoliation, over the 3–5 m search radii tested. We concluded that plot-level defoliation and basal area were adequate for modeling individual tree defoliation, and although clustering of defoliation was evident, larger plots were needed to determine the optimum neighborhood radius for predicting defoliation on an individual. Spatial autocorrelation analysis can serve as an objective way to quantify such ecological patterns.


1989 ◽  
Vol 19 (12) ◽  
pp. 1616-1624 ◽  
Author(s):  
Harald Piene

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.


1996 ◽  
Vol 26 (10) ◽  
pp. 1838-1848 ◽  
Author(s):  
P. Lejeune

A model predicting circumference growth of individual trees has been developed for mixed irregular stands dominated by Fagussilvatica L. in southeastern Belgium. This model integrates simultaneously tree, stand, and growing site characteristics without considering distances between individual trees. It has a determination coefficient of 40.1% and a residual standard deviation of 0.45 cm/year. Forest mensuration variables considered in the model are circumference, tree social position represented by the total basal area of trees greater than the subject tree, stand basal area, and some index of stand structure corresponding to the ratio of the variance over the mean circumference. The site component is essentially expressed by the length of the growing period. The low accuracy obtained for individual tree growth is relative because the results are used mainly after individual trees have been distributed into size classes. We have been able to show that the introduction of crown description in the model can increase its accuracy. But this modification requires a submodel describing crown changes over time.


1987 ◽  
Vol 4 (2) ◽  
pp. 73-75 ◽  
Author(s):  
Harold O. Batzer ◽  
John W. Benzie ◽  
Michael P. Popp

Abstract An aspen/balsam fir study area in Wisconsin with several replicated cutting treatments dating from 1950 when the stand was 36 years old became infested by the spruce budworm in 1976. Remeasurement in 1981 revealed that balsam fir mortality and growth loss were directly related to the amount of aspen removed from the overstory. Complete and commercial clearcutting of the overstory aspen produced 60% more balsam fir basal area than uncut plots by 1975. However, mortality from budworm defoliation averaged 98% of the basal area in these plots. Thinning from above best achieved the objective of early release and provided near maximum protection from the spruce budworm. North. J. Appl. For. 4:73-75, June 1987.


1989 ◽  
Vol 19 (10) ◽  
pp. 1211-1217 ◽  
Author(s):  
Harald Piene

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.


2020 ◽  
Vol 42 (1) ◽  
Author(s):  
Nguyen Thanh Tuan ◽  
Vu Dinh Duy ◽  
Shen H-L

The aim of this study was to explore the correlation of competition indices (CIs) on individual tree growth for Korean pine (Pinus koraiensis) plantation using partial correlation analysis and generalized linear models. The data were collected from 15 permanent plots in Mengjiagang forestry farm, Northeast China. The results showed that the distance dependent CIs have a higher predictive capacity for individual growth of pine trees. The control index of competitive trees number (CI1) combined with the selection fixed competitor trees (M2) was found to be the most well correlated competition measure with five - years diameter increment. Thus, the competition index (CI1- M2) was recommended for developing individual tree growth models. The subject tree diameter at breast height, crown width, height to crown base, tree volume and basal area all showed a significantly linear correlation with tree competition intensity (P < 0,05). Diameter at breast height, crown width, tree volume and basal area all decreased with increasing competition intensity, whereas the height to crown base increased. There was no significant relationship between competition intensity and tree height (P > 0,05). The optimal model of predicting individual growth with logarithm of diameter at breast height and CIs as the independent variables due to the best fitting performance. This results also showed considerable improvement in predicting individual tree periodic growth when including competition indices that the mean absolute error is reduced in the range of 22−25%. 


1988 ◽  
Vol 18 (6) ◽  
pp. 789-795 ◽  
Author(s):  
Gregory A. Reams ◽  
Thomas B. Brann ◽  
William A. Halteman

A nonparametric model that relates spruce budworm (Choristoneurafumiferana (Clem.)) and blowdown-caused mortality of balsam fir trees (Abiesbalsamea (L.) Mill.) to individual tree and stand characteristics is presented. Estimation of the annual base-line hazard, λ0(t), also known in epidemiological research as the force of mortality or the instantaneous rate of death, provides an explicit estimate of the rate of change (accelerating or decelerating) of cause-specific mortality during the spruce budworm outbreak. Interpretation of the spruce budworm mortality model indicates that suppressed trees are more likely to survive than the other crown classes. In general, mortality caused by spruce budworm increased with increasing cumulative plot defoliation, increasing spruce (Picea spp.) and balsam fir basal area per hectare, and decreasing hardwood basal area per hectare. Interpretation of the blowdown model indicates that blowdown mortality generally increases with increasing balsam fir, spruce, and percent balsam fir basal areas per hectare and decreasing cumulative plot defoliation.


1985 ◽  
Vol 61 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Louis Archambault ◽  
Jean Beaulieu

A method was developed to determine the growth losses in volume in surviving balsam fir following a spruce budworm outbreak that occurred in the Ottawa River Valley in Quebec. Equations expressing the diameter growth rate had there been no infestation were developed. These equations were applied to balsam fir surviving the epidemic so as to determine what their diameters would have been without defoliation. Subsequently, the theoretical volumes were assessed using these diameters. The method was validated for the pre-epidemic period and precision was superior to 90%. Analyses revealed the outbreak caused a 49% volume growth loss to balsam fir for a period of approximately 10 years. Key words: Spruce budworm (Choristoneura fumiferana (Clem.)), balsam fir (Abies balsamea (L.) Mill.), growth losses.


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