Succession écologique des forêts d'épinette blanche et fluctuations climatiques, Poste-de-la-Baleine, Nouveau-Québec

1976 ◽  
Vol 54 (12) ◽  
pp. 1394-1402 ◽  
Author(s):  
Serge Payette

The stand structures of three white spruce (Picea glauca (Moench) Voss) climax forests of the hemiarctic zone in New Quebec are described. The forests have a similar structural pattern, characterized by important and irregular variations in the number of individuals per age, diameter, and height classes. These variations are synchronic and suggest that the climate strongly influences the forest regeneration. The discontinuous trend in the curves may possibly be related to changes in seed production and seedling establishment. Synchronism between the 300-year dendrochronological curve and the stand age-structure is apparent. The hollow parts of the age curves are related to unfavorable climatic periods and the peaks to favorable ones. These climatic fluctuations are probably responsible for either a decrease or an increase in white spruce seed production important to hemiarctic forest regeneration. Finally, the writer suggests a theoretical age-structure curve for climax forests in the maritime forest-tundra near Poste-de-la-Baleine, New Quebec.


1981 ◽  
Vol 113 (10) ◽  
pp. 949-951 ◽  
Author(s):  
W. H. Fogal ◽  
D. A. Winston ◽  
S. M. Lopushanski ◽  
D. A. MacLeod ◽  
A. J. Willcocks

White spruce, Picea glauca (Moench) Voss, is a major commercial tree species used in reforestation programs throughout Canada, and seed requirements cannot be met in some years because of insect damage and the periodic nature of cone crops. The spruce budworm, Choristoneura fumiferana (Clem.), feeds on buds and cones of its hosts, causing a pronounced decrease in cone production (Schooley 1978). A current outbreak in northeastern Ontario poses a serious threat to white spruce seed supply from high value, managed seed production areas. Therefore, in 1979, we began an experiment to determine whether carbofuran, a systemic insecticide, could be used to protect buds and cones when applied to soil. We chose carbofuran because it has proved successful for control of some insects in seed orchards in the southeastern United States (DeBarr 1978)



1956 ◽  
Vol 32 (4) ◽  
pp. 400-410 ◽  
Author(s):  
Howard A. Tripp ◽  
Alan F. Hedlin

This paper discusses insects which inhabit the cones of white spruce, Picea glauca (Moench) Voss, in Ontario and Saskatchewan. Insects which spend their entire developmental stages within the cone and cause appreciable damage are discussed at greater length. In Ontario, these are the spruce seedworm, Laspeyresia youngana (Kft.) and the spruce cone maggot, Pegohylemyia anthracina Czerny. In Saskatchewan, L. youngana is the main offender. Other insects which are of less economic importance from the standpoint of seed production are gall midges (cecidomyiids) and casual cone feeders.



2010 ◽  
Vol 142 (3) ◽  
pp. 261-270 ◽  
Author(s):  
Simon P. Daoust ◽  
Brian J. Mader ◽  
Eric Bauce ◽  
Emma Despland ◽  
Audrey Dussutour ◽  
...  

AbstractA white spruce, Picea glauca (Moench) Voss (Pinaceae), plantation in southern Quebec was found to contain two distinct types of trees, the first resistant and the second susceptible to attack by spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae). To identify the mechanisms of white spruce resistance to spruce budworm, we studied the role of epicuticular waxes, comparing (i) the foliar chemistry of susceptible and resistant trees and (ii) the feeding pattern of larvae at first contact with the foliage. Needles collected from resistant trees contained concentrations of the monoterpenes α-pinene and myrcene that were 307% and 476%, respectively, above those found in needles collected from susceptible trees. Although there were no significant differences in probing behaviour, significantly fewer larvae transitioned from probing to feeding on resistant needles; this led to fewer feeding bouts as well as a significantly shorter first meal. Removal of waxes increased the number of individuals transitioning from probing to feeding on resistant needles; this led to more feeding bouts. Our results demonstrate that monoterpenes influence the pattern of feeding of spruce budworm larvae as well as playing an important role in white spruce resistance.



1982 ◽  
Vol 58 (1) ◽  
pp. 31-34 ◽  
Author(s):  
J. A. McPherson ◽  
E. K. Morgenstern ◽  
B. S. P. Wang

One seed orchard each of black spruce (Picea mariana) [Mill.] B.S.P.) and white spruce (Picea glauca) [Moench] Voss) was established in northern Ontario gradually during the 1958-78 period. Each species was represented by approximately 45 clones and 450 ramets. During the whole period, records were kept of cone production by individual ramets and of seed production by clones expressed as average number of seeds per cone extracted and germinated. Substantial cone production began 8 years after grafting in black spruce and after 10 years in white spruce. The figures indicated that a clonal orchard of black spruce planted at 5 × 5 m spacing (400 ramets) produces approximately 1 million sound seeds per ha per year; the white spruce equivalent is 900 000. Conditions of cone development and cone storage and damage by insects and fungi can reduce germination of the sound seed harvested by about 20%.



2009 ◽  
Vol 39 (10) ◽  
pp. 1997-2004 ◽  
Author(s):  
Steve Cumming ◽  
Mariana Trindade ◽  
David Greene ◽  
S. Ellen Macdonald

In mixedwood boreal forests of western Canada, stands classified as “pure deciduous” by forest inventories sometimes contain a few large white spruce (Picea glauca (Moench) Voss) trees among or emerging from the canopy. These trees are important as regeneration seed sources and for habitat structure. Neither their abundance nor the characteristics of stands in which they occur have previously been quantified. Of 275 “pure aspen” stands in northeastern Alberta, 19.6% contained at least one such spruce detectable in an aerial photograph. These trees were found in stands across the range of sampled canopy heights, densities, age classes, and stand sizes and were often present in the interior of stands, not just on the perimeter. The frequency of 3 ha cells containing at least one spruce was related to (i) stand shape and size, (ii) amount of mature white spruce in adjacent forest, (iii) canopy height, (iv) stand age, and (v) stand density. We conclude that such trees are relatively abundant and widely distributed within the boreal mixedwood forests of Alberta. There is presently no provision to maintain this landscape element within managed forests. More information is needed to determine if or how they should be considered in forest management planning.



1997 ◽  
Vol 129 (2) ◽  
pp. 291-318 ◽  
Author(s):  
Robert K. Lawrence ◽  
William J. Mattson ◽  
Robert A. Haack

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.



Botany ◽  
2011 ◽  
Vol 89 (5) ◽  
pp. 323-338 ◽  
Author(s):  
A. Tsuneda ◽  
M.L. Davey ◽  
R.S. Currah

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.



1989 ◽  
Vol 19 (3) ◽  
pp. 295-308 ◽  
Author(s):  
R. D. Whitney

In an 11-year study in northern Ontario, root rot damage was heaviest in balsam fir, intermediate in black spruce, and least in white spruce. As a result of root rot, 16, 11, and 6%, respectively, of dominant or codominant trees of the three species were killed or experienced premature windfall. Butt rot, which resulted from the upward extension of root rot into the boles of living trees, led to a scaled cull of 17, 12, and 10%, respectively, of gross merchantable volume of the remaining living trees in the three species. The total volume of wood lost to rot was, therefore, 33, 23, and 16%, respectively. Of 1108 living dominant and codominant balsam fir, 1243 black spruce, and 501 white spruce in 165 stands, 87, 68, and 63%, respectively, exhibited some degree of advanced root decay. Losses resulting from root rot increased with tree age. Significant amounts of root decay and stain (>30% of root volume) first occurred at 60 years of age in balsam fir and 80 years in black spruce and white spruce. For the three species together, the proportion of trees that were dead and windfallen as a result of root rot increased from an average of 3% at 41–50 years to 13% at 71–80 years and 26% at 101–110 years. The root rot index, based on the number of dead and windfallen trees and estimated loss of merchantable volume, also increased, from an average of 17 at 41–50 years to 40 at 71–80 years and 53 at 101–110 years. Death and windfall of balsam fir and black spruce were more common in northwestern Ontario than in northeastern Ontario. Damage to balsam fir was greater in the Great Lakes–St. Lawrence Forest region than in the Boreal Forest region. In all three tree species, the degree of root rot (decay and stain) was highly correlated with the number of dead and windfallen trees, stand age, and root decay at ground level (as a percentage of basal area) for a 10-tree sample.



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