POPULATION TRENDS OF A SPECIALIST HERBIVORE, THE SPRUCE BUD MOTH, IN YOUNG WHITE SPRUCE STANDS

2000 ◽  
Vol 132 (6) ◽  
pp. 825-842 ◽  
Author(s):  
Don P. Ostaff ◽  
Dan T. Quiring
Keyword(s):  
Picea Glauca ◽  
Larval Density ◽  
Population Decline ◽  
Survival Rates ◽  
White Spruce ◽  
Larval Survival ◽  
Tree Age ◽  
Population Increase ◽  
Specialist Herbivore ◽  
Crown Closure

AbstractWe investigated the factors responsible for changes in abundance of the spruce bud moth, Zeiraphera canadensis Mut. and Free. (Lepidoptera: Tortricidae) in one unmanaged and several managed (i.e., planted) young white spruce, Picea glauca (Moench.) Voss (Pinaceae), stands in northern New Brunswick, Canada. Spruce bud moth densities declined when one stand closed (branches from neighbouring trees overlapped) and had already declined in another similarly aged closed stand, but remained high on 8- to 22-year-old open-grown white spruce. Both the intrageneration survival rate and the egg-to-moth ratios increased when population densities increased, and generally decreased, although the egg-to-moth ratio fluctuated, during the population decline in a managed stand. Increases in intrageneration survival rates of spruce bud moth on 5- to 10-year-old trees were due to increased larval or pupal survival. Crown closure explained 76 and 81% of the variability in larval and intrageneration survival, respectively, in four managed stands. The strong inverse relationship between larval survival and degree of crown closure resulted in statistically significant but spurious relationships between larval survival and larval density and between larval survival and tree age. A reduction in larval survival occurring as degree of crown closure increased was the most important factor influencing decreases in intrageneration survival at the beginning of population decline. Increases in the egg-to-moth ratio during the population increase, and decrease during population decline, suggested that dispersal behaviour and (or) realized fecundity of females also contributed to annual changes in population.

An endophytic fungus interacts with crown level and larval density to reduce the survival of eastern spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae), on white spruce (Picea glauca)

2019 ◽  
Vol 49 (3) ◽  
pp. 221-227 ◽  
Author(s):  
Dan Quiring ◽  
Leah Flaherty ◽  
Greg Adams ◽  
Andrew McCartney ◽  
J. David Miller ◽  
...  
Keyword(s):  
Endophytic Fungus ◽  
Picea Glauca ◽  
Significant Interaction ◽  
Choristoneura Fumiferana ◽  
Larval Density ◽  
Spruce Budworm ◽  
White Spruce ◽  
Larval Survival ◽  
Total Survival ◽  
Eastern Spruce Budworm

A two-year field study was carried out to determine whether inoculating white spruce, Picea glauca (Moench) Voss, with a native endophytic fungus, Phialocephala scopiformis DAOM 229536 Kowalski & Kehr (Helotiales, Ascomycota), decreased the performance of eastern spruce budworm, Choristoneura fumiferana Clemens, developing on these trees. Second instars were reared at three densities in the mid crown and at one density in the lower, mid, and upper crown. Larval survival (i.e., survival of larvae to pupation) was lower on endophyte-inoculated trees than on control trees in the mid crown and especially the upper crown but was similar in the lower crown, resulting in a significant interaction between endophyte and crown level. A similar but marginally insignificant interaction was observed for overall survival up to adult emergence (i.e., total survival). Larval survival and total survival were approximately 22% and 19% lower, respectively, when developing in the upper crown of endophyte-inoculated trees than in control trees. Larval survival remained relatively constant, with increased density on control trees but decreased with density on endophyte-inoculated trees, resulting in a significant interaction between endophyte and larval density. Sex ratios of emerged adults and wing lengths of emerged females were not influenced by the endophyte. Our results suggest that endophytic fungi could be useful additions to integrated pest management programs.

WHITE SPRUCE AND THE SPRUCE BUDWORM: DEFINING THE PHENOLOGICAL WINDOW OF SUSCEPTIBILITY

1997 ◽  
Vol 129 (2) ◽  
pp. 291-318 ◽  
Author(s):  
Robert K. Lawrence ◽  
William J. Mattson ◽  
Robert A. Haack
Keyword(s):  
Picea Glauca ◽  
High Performance ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
White Spruce ◽  
Shoot Elongation ◽  
Larval Survival ◽  
Strongly Correlated ◽  
Negative Effect ◽  
Foliar Traits

AbstractSynchrony of insect and host tree phenologies has often been suggested as an important factor influencing the susceptibility of white spruce, Picea glauca (Moench) Voss, and other hosts to the spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae). We evaluated this hypothesis by caging several cohorts of spruce budworm larvae on three white spruce populations at different phenological stages of the host trees, and then comparing budworm performance with host phenology and variation of 13 foliar traits. The beginning of the phenological window of susceptibility in white spruce occurs several weeks prior to budbreak, and the end of the window is sharply defined by the end of shoot growth. Performance was high for the earliest budworm cohorts that we tested. These larvae began feeding 3–4 weeks prior to budbreak and completed their larval development prior to the end of shoot elongation. Optimal synchrony occurred when emergence preceded budbreak by about 2 weeks. Larval survival was greater than 60% for individuals starting development 1–3 weeks prior to budbreak, but decreased to less than 10% for those starting development 2 or more weeks after budbreak and thus completing development after shoot elongation ceased. High performance by the budworm was most strongly correlated with high levels of foliar nitrogen, phosphorous, potassium, copper, sugars, and water and low levels of foliar calcium, phenolics, and toughness. These results suggest that advancing the usual phenological window of white spruce (i.e. advancing budbreak prior to larval emergence) or retarding budworm phenology can have a large negative effect on the spruce budworm’s population dynamics.

Soil carbon sequestration with forest expansion in an arctic forest–tundra landscape

2004 ◽  
Vol 34 (7) ◽  
pp. 1538-1542 ◽  
Author(s):  
Heidi Steltzer
Keyword(s):  
Soil Carbon ◽  
Picea Glauca ◽  
White Spruce ◽  
Tree Age ◽  
Forest Expansion ◽  
Soil C ◽  
C Storage ◽  
C Pools ◽  
Sampling Locations

Soil carbon (C) and nitrogen (N) pools were measured under the canopy of 29 white spruce (Picea glauca (Moench) Voss) trees and in the surrounding tundra 3 and 6 m away from each tree at three sites of recent forest expansion along the Agashashok River in northwestern Alaska. The aim was to characterize the potential for forest expansion to lead to increased soil C pools across diverse tundra types. Soil C beneath the trees correlated positively with tree age, suggesting that tree establishment has led to C storage in the soils under their canopy at a rate of 18.5 ± 4.6 g C·m–2·year–1. Soil C in the surrounding tundra did not differ from those under the trees and showed no relationship to tree age. This characterization of the soil C pools at the 3-m scale strengthens the assertion that the pattern associated with the trees is an effect of the trees, because tree age cannot explain variation among tundra sampling locations at this scale. Potential mechanisms by which these white spruce trees could increase soil C pools include greater production and lower litter quality.

White spruce establishment in boreal Ontario mixedwood: 5-year results

1995 ◽  
Vol 71 (5) ◽  
pp. 633-638 ◽  
Author(s):  
R. F. Sutton ◽  
T. P. Weldon
Keyword(s):  
Picea Glauca ◽  
Relative Effectiveness ◽  
Survival Rates ◽  
Growing Season ◽  
White Spruce ◽  
Site Preparation ◽  
Mechanical Site Preparation ◽  
Growing Seasons ◽  
Silvicultural Treatments ◽  
Block Experiment

Five-year results of a study to evaluate the relative effectiveness of nine silvicultural treatments for establishing plantations of white spruce (Picea glauca [Moench] Voss) in boreal Ontario mixed-wood are presented. The experimental design provided three levels of mechanical site preparation (none, disk trenching, and toothed-blading) in all combinations with three kinds of chemical weed control (none, Velpar L© at the time of planting, and Vision© during the second growing season). A randomized block experiment using 0.8-ha plots and two replications was established in Oates Twp. in 1985 and repeated in adjacent Oswald Twp. in 1986. Bareroot white spruce was planted throughout. Four 25-tree sub-plots, located systematically from a random start, were established in each plot. White spruce performance was monitored for five years. Fifth-year survival rates averaged 34% and 84% without and with mechanical site preparation, respectively. Mean total heights after five growing seasons differed significantly (P < 0.01) by category of mechanical site preparation: teeth > trencher > none. Other criteria of performance showed the same pattern. Because of operational exigencies, the herbicide treatments were not applied as scheduled, which might account for the apparent ineffectiveness of those treatments in the particular circumstances of this study. Key words: Site preparation, disk trencher, Young's teeth, herbicides

Rapid change in suitability of white spruce for a specialist herbivore, Zeiraphera canadensis, as a function of leaf age

1992 ◽  
Vol 70 (11) ◽  
pp. 2132-2138 ◽  
Author(s):  
D. T. Quiring
Keyword(s):  
Picea Glauca ◽  
Leaf Age ◽  
Rapid Change ◽  
White Spruce ◽  
Field Studies ◽  
Host Suitability ◽  
Rapid Decline ◽  
Bud Burst ◽  
Specialist Herbivore ◽  
Sib Families

Field studies were carried out over 2 years to determine the effect of age of white spruce (Picea glauca) leaves on the development of the spruce bud moth, Zeiraphera canadensis Mut. &Free. (Lepidoptera: Tortricidae). In both years developing buds remained suitable for first-instar larvae for only 4–5 days after bud burst, after which survivorship decreased significantly. Individuals that survived on flaring shoots were smaller than those placed on newly burst buds. Although leaf contents of water, nitrogen, and several minerals were inversely related to leafage, only declines in N and P content were associated with the rapid change in host suitability. Differences in N and P contents were small, however, suggesting that the rapid decline in host suitability was also due to the influence of other, unmeasured factors. When larvae were placed on foliage of the same age, their survival was similar on trees in half-sib families with high or low susceptibility to Z. canadensis. Thus, variations in susceptibility of white spruce to Z. canadensis might be associated with differences in host-plant phenology but are not due to differences in nutritional quality. This study demonstrates that the phenological window for establishment of newly emerged folivores may be shorter than is commonly thought.

Age and size effects on first cone production among white spruce trees

2020 ◽  
Vol 50 (5) ◽  
pp. 519-522
Author(s):  
Michael T. Bronson
Keyword(s):  
Picea Glauca ◽  
Tree Height ◽  
White Spruce ◽  
Tree Age ◽  
Population Changes ◽  
Growth Rings ◽  
Reproductive Maturity ◽  
Cone Production ◽  
Competition For Light ◽  
Effect Of Age

The onset of lifetime reproduction is central to processes of plant adaptation and population changes. The relative contributions of size and age to the onset of reproduction are important to predicting that key event in individuals. To estimate respective size and age effects on first reproduction in a conifer, I observed white spruce (Picea glauca (Moench) Voss) trees in forest stands in Alaska, United States, over ranges of cumulative growth rates. Age was estimated by counting annular growth rings, size was indicated by tree height, and reproductive status was indicated by seed cones. Multiple logistic regression showed the relative contributions of tree height and age, adjusted for each other, to statistical predictions of reproductive maturity. Trees selected for having little competition for light first produced cones at heights between 1 and 5 m with little additional effect of age. Tree height contributed approximately 50% to regression predictions of reproductive maturity. In contrast, tree age contributed ≤1.5% and bore little relation to reproductive maturity other than as a component of growth rate. This is among the first reports to partial the effect sizes of tree size and age on the commencement of lifetime reproduction in a conifer.

scholarly journals THE EFFECT OF TWO PLANTING METHODS ON THE SURVIVAL AND GROWTH OF WHITE SPRUCE (Picea glauca (MOENCH) VOSS) IN EASTERN ONTARIO

1958 ◽  
Vol 34 (4) ◽  
pp. 376-379 ◽  
Author(s):  
K. A. Armson
Keyword(s):  
Water Table ◽  
Sandy Soil ◽  
Picea Glauca ◽  
Survival Rates ◽  
White Spruce ◽  
Planting Methods ◽  
Survival And Growth ◽  
Eastern Ontario ◽  
The Difference ◽  
Method Of Planting

White spruce trees were planted in the Larose County Forest, Ontario, on a sandy soil which has a permanent water table 6-24 inches below the surface. In one method of planting the trees were placed in the bottom of the furrow, and in a second method they were planted in the upturned furrow slice. Eight years after planting there was found to be no difference in the survival rates of trees planted by either method, but the height of those trees planted in the upturned furrow slice was significantly greater than that of trees planted in the bottom of the furrow. The difference in height appeared to be related to the fact that those trees planted in the furrow bottoms had their roots placed in a zone of the soil which is seasonally saturated with water.

Life history traits of Aedes caspius (Diptera: Culicidae): a laboratory study of larval stages

2008 ◽  
Vol 98 (5) ◽  
pp. 431-436 ◽  
Author(s):  
A. Carron ◽  
L. Bichaud ◽  
N. Platz ◽  
D.J. Bicout
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Larval Density ◽  
Survival Rates ◽  
Control Program ◽  
Larval Survival ◽  
Fourth Instar ◽  
Aedes Caspius ◽  
Development Times ◽  
Two Populations

AbstractThe larval survival and development times of Aedes caspius (Diptera: Culicidae) were examined in the laboratory. These life history traits were estimated using life tables constructed for two populations, one of which had been subjected to a long-term larvicide control program. Traits were evaluated for eight different population densities. The effects of population, larval stage and larval density were investigated using a general linear model. Density was positively correlated with larval survival but did not affect development time. The fourth instar and pupae had the lowest larval survival rates. First and fourth instar larvae had the longest development times. These traits were not significantly different between the two populations. The effect of larvicide control on these traits is discussed.

scholarly journals Population Differentiation and Climatic Adaptation for Growth Potential of White Spruce (Picea glauca) in Alberta, Canada

2010 ◽  
Vol 59 (1-6) ◽  
pp. 158-169 ◽  
Author(s):  
Deogratias M. Rweyongeza ◽  
L. K. Barnhardt ◽  
N. K. Dhir ◽  
C. Hansen
Keyword(s):  
Picea Glauca ◽  
Time Series Data ◽  
Principal Component ◽  
High Growth ◽  
White Spruce ◽  
Growth Potential ◽  
Tree Age ◽  
Series Data ◽  
Climatic Index ◽  
Different Ages

AbstractGenetic differentiation among white spruce populations in Alberta, Canada, was studied using time series data of height and diameter and a climatic index developed by principal component analysis. The objectives were to discern patterns of variation for growth potential and predicted optimum climate; compare optimum climate between populations, between height and diameter at the same age and between height or diameter at different ages; and to see if optimum climate differed from the climate inhabited by populations. Using cluster analysis we found that: (1) populations from mid-latitudes (54° - 57°N) and mid-elevations (600 - 800 m) were grouped together and exhibited high growth potential; populations from north of 57°N were grouped with those from elevations higher than 900m in the Rocky Mountains and exhibited low growth potential; and (2) With minor exceptions, populations from similar climates or geography were grouped together in terms of predicted optimum climate. (3) Analysis of variance showed that optimum climate differed significantly (P < 0.05) among populations; among heights at different ages; among diameters at different ages and between height and diameter at the same ages. However, there was no consistent trend in the direction of change in optimum climate with tree age. (4) The range of climate inhabited by the populations (PI₁= -5.792 to 4.483) was much wider than the range of their predicted optimum climate (P̂Ō₁= -1.001 to 0.842), which suggests that in terms of growth potential some populations inhabit sub-optimal climates. Implications of the results on management of white spruce in Alberta are discussed.

Effects of stand tending on the estimation of aboveground biomass of planted juvenile white spruce

2004 ◽  
Vol 34 (3) ◽  
pp. 649-658 ◽  
Author(s):  
Douglas G Pitt ◽  
F Wayne Bell
Keyword(s):  
Aboveground Biomass ◽  
Picea Glauca ◽  
Tree Height ◽  
White Spruce ◽  
Biomass Estimation ◽  
Total Biomass ◽  
Coefficients Of Variation ◽  
Biomass Components ◽  
Branch Biomass ◽  
Crown Closure

Stem, branch, needle, and total aboveground biomass were assessed for three 9- to 12-year-old white spruce (Picea glauca (Moench) Voss) plantations, each subjected to three different stand tending options at age 4 to 7. Biomass components were predicted from measures of stem diameter with coefficients of variation between 24% and 29%. Diameter at breast height (DBH) generally provided lower prediction precision than did the lower stem measures tested (coefficient of variation > 35%). The addition of tree height in models reduced the standard error of the estimates for stem and total biomass by an average of 48% and 8%, respectively, and compensated for different height/diameter ratios imposed on the spruce by the stand tending treatments. Needle and branch biomass models were invariant to the tending treatments and, consequently, to the addition of height as an independent variable. Predictions from existing published white spruce equations suggest that extrapolation to this study area would have led to adequate stem biomass estimation but to serious (>55%) underestimates of branch, needle, and, correspondingly, total biomass. Slow self-pruning by plantation spruce, particularly before crown closure, is cited as a possible reason for these differences.

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