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.

Investigation of limestone ecotypes of white spruce based on a provenance test series

2004 ◽  
Vol 34 (5) ◽  
pp. 1119-1127 ◽  
Author(s):  
Mark R Lesser ◽  
Marilyn Cherry ◽  
William H Parker
Keyword(s):  
Picea Glauca ◽  
White Spruce ◽  
Field Studies ◽  
Test Site ◽  
Parent Material ◽  
Survey Analysis ◽  
Data Set ◽  
Provenance Trials ◽  
Provenance Test ◽  
Limestone Bedrock

Previous laboratory and field studies have presented evidence for the existence of limestone ecotypes in white spruce (Picea glauca (Moench) Voss). Remeasurements of the range-wide 410 series of provenance trials were used for further evaluation of the existence of these ecotypes. In 2001, heights were measured of 23 provenances grown at four test sites in Ontario, all located south of 46°N. Bedrock classification for test sites and provenances by limestone or non-limestone parent material was done using a 1993 data set of the Ontario Geological Survey. Analysis of variance revealed significant differences among test sites and provenances only. No significant interactions consistent with the existence of limestone ecotypes were detected. This finding is in contrast to that of an earlier field study that detected a strong interaction between test site and provenance bedrock type (p < 0.001). Examination of the relative performance of individual provenances from limestone and non-limestone bedrock types revealed differences in performance at the four different test sites but few instances supporting the existence of limestone ecotypes. Although these more recent results generally support a pattern of between-stand variation in southern Ontario, they do not disprove the existence of limestone ecotypes, owing to the nature of the 410-series test design and the classification of provenances according to bedrock type instead of actual soil analyses.

Climatic warming and its effect on bud burst and risk of frost damage to white spruce in Canada

1998 ◽  
Vol 74 (4) ◽  
pp. 567-577 ◽  
Author(s):  
Stephen J. Colombo
Keyword(s):  
Climate Warming ◽  
Picea Glauca ◽  
Global Climate ◽  
White Spruce ◽  
Frost Damage ◽  
Weather Data ◽  
Bud Burst ◽  
Freezing Damage ◽  
Local Climate ◽  
Frost Risk

Temperature data from ten weather stations across Canada were used to model the effects of climate warming on the timing of bud burst and the risk of frost damage to white spruce (Picea glauca (Moench) Voss). There was evidence of increasingly earlier dates of bud break over the course of this century at half of the stations examined (Amos and Brome, Québec; Cochrane, Ontario; Fort Vermilion, Alberta; and Woodstock, New Brunswick), with the period 1981 to 1988 having the earliest predicted dates of bud burst (earliest degree day accumulation). Risk of frost damage at most stations in the 1980s was usually greater than in earlier periods. Weather data modelled for climate warming of 5 °C predicts that bud burst will occur two to four weeks sooner than was the case during 1961 to 1980 at all stations, but that this will generally be accompanied by decreased risk of frost after bud burst. However, while the expected trend is one of reduced frost risk in the future, as the climate gradually warms frost risk is expected to fluctuate upward or downward depending on interactions between provenance and local climate. Key words: bud burst, climate warming, dormancy, freezing damage, frost, global climate change, Picea glauca, white spruce

Comparison of early height growth between white spruce seedlings and rooted cuttings

2006 ◽  
Vol 36 (12) ◽  
pp. 3246-3250 ◽  
Author(s):  
J Beaulieu ◽  
M Bernier-Cardou
Keyword(s):  
Growth Rate ◽  
Picea Glauca ◽  
Relative Size ◽  
White Spruce ◽  
Breeding Population ◽  
Height Growth ◽  
Rooted Cuttings ◽  
Average Growth ◽  
Sib Families ◽  
Growth Features

Early height growth of eastern white spruce (Picea glauca (Moench) Voss) rooted cuttings was compared with that of seedlings using annual measurements collected over 5 years in a farm field test replicated on three sites. The experiment included 148 full-sib families obtained from controlled crossings of superior trees selected for a white spruce breeding population in Quebec. Fifteen additional seedlots were used as controls. The average growth rate of seedlings (37.3 cm·year–1) was slightly larger than that of rooted cuttings (36.2 cm·year–1). The yearly growth rate increased over the test period, and it did so at a somewhat higher rate for the seedlings. The relative size of the estimated variance components and the moderate rank correlations of full-sib family height growth features between the two propagule types suggest that tree breeders should favour seedlings over rooted cuttings to rank families for selection purposes, but vegetative propagation would prove useful for bulking up scarce valuable genotypes.

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.

Collective Memory: Between Values and Historical Knowledge

2020 ◽  
pp. 124-142
Author(s):  
VICTOR BURLACHUK
Keyword(s):  
Twentieth Century ◽  
Soviet Union ◽  
Collective Memory ◽  
Rapid Change ◽  
Modern Society ◽  
The State ◽  
Main Element ◽  
Rapid Decline ◽  
The Past ◽  
The Future

At the end of the twentieth century, questions of a secondary nature suddenly became topical: what do we remember and who owns the memory? Memory as one of the mental characteristics of an individual’s activity is complemented by the concept of collective memory, which requires a different method of analysis than the activity of a separate individual. In the 1970s, a situation arose that gave rise to the so-called "historical politics" or "memory politics." If philosophical studies of memory problems of the 30’s and 40’s of the twentieth century were focused mainly on the peculiarities of perception of the past in the individual and collective consciousness and did not go beyond scientific discussions, then half a century later the situation has changed dramatically. The problem of memory has found its political sound: historians and sociologists, politicians and representatives of the media have entered the discourse on memory. Modern society, including all social, ethnic and family groups, has undergone a profound change in the traditional attitude towards the past, which has been associated with changes in the structure of government. In connection with the discrediting of the Soviet Union, the rapid decline of the Communist Party and its ideology, there was a collapse of Marxism, which provided for a certain model of time and history. The end of the revolutionary idea, a powerful vector that indicated the direction of historical time into the future, inevitably led to a rapid change in perception of the past. Three models of the future, which, according to Pierre Nora, defined the face of the past (the future as a restoration of the past, the future as progress and the future as a revolution) that existed until recently, have now lost their relevance. Today, absolute uncertainty hangs over the future. The inability to predict the future poses certain challenges to the present. The end of any teleology of history imposes on the present a debt of memory. Features of the life of memory, the specifics of its state and functioning directly affect the state of identity, both personal and collective. Distortion of memory, its incorrect work, and its ideological manipulation can give rise to an identity crisis. The memorial phenomenon is a certain political resource in a situation of severe socio-political breaks and changes. In the conditions of the economic crisis and in the absence of a real and clear program for future development, the state often seeks to turn memory into the main element of national consolidation.

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.

A new endoconidial black meristematic genus, Atramixtia, associated with declining white spruce and phylogenetically allied to a lineage of dothidealean conifer pathogens

Botany ◽  
2011 ◽  
Vol 89 (5) ◽  
pp. 323-338 ◽  
Author(s):  
A. Tsuneda ◽  
M.L. Davey ◽  
R.S. Currah
Keyword(s):  
Plant Tissue ◽  
Picea Glauca ◽  
White Spruce ◽  
Natural Substrate ◽  
Dividing Cells ◽  
Granular Matrix ◽  
Phylogenetic Affinities

An endoconidial, black meristematic taxon Atramixtia arboricola gen. et. sp. nov. (Dothideales) from the black subicula found on twigs of declining white spruce, Picea glauca (Moench) Voss, in Alberta is described. It is morphologically distinguishable from other endoconidial taxa by the conidioma composed of clumps of endoconidial conidiogenous cells, scattered meristematically dividing cells, dematiaceous hyphae, abundant brown, granular matrix materials, and sometimes plant tissue. Endoconidia also occur in conidiogenous cellular clumps that are not organized into a conidioma but develop directly from stromatic cells on the bark. In culture, it forms similar endoconidial conidiomata and also a mycelial, blastic synanamorph that superficially resembles Hormonema . Atramixtia arboricola is a member of the Dothideales and shows phylogenetic affinities to a clade of conifer-stem and -needle pathogens, including Sydowia and Delphinella , although no teleomorph was found either on the natural substrate or in culture. It has not been determined whether A. arboricola is pathogenic to its host, but the occurrence of abundant intracellular hyphae in the host periderm suggests that the fungus is at least parasitic.

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.

Sign in / Sign up

Export Citation Format

Share Document