Seasonal growth of black spruce and tamarack roots in an Alberta peatland

1993 ◽  
Vol 71 (2) ◽  
pp. 359-360 ◽  
Author(s):  
Timothy S. S. Conlin ◽  
Victor J. Lieffers

Seasonal growth of black spruce (Picea mariana Mill. BSP) and tamarack (Larix laricina (Du Roi) K. Koch) roots in an Alberta peatland were assessed by measuring growth into emplaced soil cores that did not contain plant roots. Five cores were positioned 1 m from the base of each tree and 10 replicates of this treatment were used for each species. Sequential lifting of these cores during the growing season showed that root growth by these species did not begin until midsummer. Tamarack root growth was restricted to August and September, while black spruce root growth continued into October. Key words: flooding, Larix laricina, peatland, phenology, Picea mariana, temperature, root growth.

1978 ◽  
Vol 54 (6) ◽  
pp. 296-297 ◽  
Author(s):  
Douglas A. Mead

Height growth of eastern larch (Larix laricina (Du Roi) K. Koch) and black spruce (Picea mariana (Mill.) B.S.P.) was determined using standard stem analysis methods on trees from two sites in northwestern Ontario. The data were obtained from mixed larch-spruce stands which were relatively undisturbed. The larch exhibited substantially better height growth than the spruce through age 65.


1997 ◽  
Vol 73 (2) ◽  
pp. 249-255 ◽  
Author(s):  
Marc R. MacDonell ◽  
Arthur Groot

A project was established in the Lake Abitibi Model Forest to study the effects of several harvesting systems on advance growth protection and site disturbance. Tree-length and cut-to-length harvesting systems were compared to a full-tree system on peatland black spruce (Picea mariana (Mill.) B.S.P.) sites. The impacts of the various harvesting systems were compared by summarizing the structural and mensurational properties of the stands before and after harvest, by evaluating damage to residual trees, and by assessing site disturbance. The tree-length and full-tree systems, which were compared in winter harvesting, produced similar results. The cut-to-length system was compared to the full-tree system in both winter and summer harvesting, and protected substantially more advance growth, especially in the summer. Additionally, the cut-to-length system produced less damage to residual trees and lesser amounts of site disturbance. All harvesting systems resulted in or maintained residual stands with an uneven-size structure. Key words: black spruce, advanced regweneration, tree harvesting, systems


1985 ◽  
Vol 63 (7) ◽  
pp. 1213-1225 ◽  
Author(s):  
Réjean Gagnon ◽  
Serge Payette

The occurrence of tamarack (Larix laricina (Du Roi) K. Koch) and black spruce (Picea mariana (Mill.) B.S.P.) macrofossils or subfossils on the tundroid patches at the forest limit indicates that those patches were colonized by trees in the past. The aim of this study is to reconstruct the fluctuations of the coniferous formations by macrofossil analysis. More than 465 macrofossils and 30 charcoals were collected, 31 and 23 of which, respectively, were 14C dated. The results of charcoal analysis indicated that fires were more frequent in the southern part of the forest limits than in the northern part. During the last millenium three periods of fire (modern, 400, and 900 years) were noted in the southern part, two periods (modern and 600 years) at the forest limit, and none north of the forest limit. The majority of collected macrofossils are from the modern period; their death is related to the action of fire. The mosaic landscape of the forest tundra is related to a deterioration of the climatic conditions coupled with the history of fires.


1999 ◽  
Vol 77 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Luc Sirois ◽  
Yves Bégin ◽  
Johanne Parent

The development of female gametophytes and embryos in relation to cumulative growing degree-days was followed to see if the postulated cooling influence of the Robert-Bourassa reservoir (LG2, northern Quebec) slowed the reproductive process of black spruce (Picea mariana (Mill.) B.S.P.). During the 1996 growing season, three to five developing seed cones were harvested 11 times on nine trees distributed along a shore-hinterland gradient of the northern shore of the reservoir. The daily thermal sum (degree-days > 5°C) in the seed cone zone of the same trees was also monitored to describe the female gametophyte and embryo development of this species as a function of heat sum. The 23 developmental stages identified in this study confirm that the female gametophyte and embryo of P. mariana develop according to the same pattern exhibited by other Picea spp. These stages, although unequal in duration, succeeded each other according to a sigmoid function of the temperature sum. Direct temperature measurements taken 0, 25, and 100 m from the shore of the Robert-Bourassa reservoir suggest the interior trees experienced 107 more degree-days > 5°C than the shoreline trees during seed maturation. Although gametophyte development of the shoreline trees was delayed early in the growing season (Kruskall-Wallis, p = 0.05), this delay does not persist afterward. Despite the net cooling effect of the Robert-Bourassa reservoir, all studied trees achieved embryo maturation in 1996. During this growing season, the warmest since 1977, it took embryos 800-940 degree-days to mature. The shoreline trees reached this temperature threshold later than interior trees. It is suggested that the cooling effect of the Robert-Bourassa reservoir could contribute to the inhibition of embryo maturation in shoreline trees during growing seasons with less than 800 degree-days.Key words: black spruce, climate change, cone development, northern boreal forests, Picea mariana, seed maturation.


1993 ◽  
Vol 125 (2) ◽  
pp. 403-404 ◽  
Author(s):  
J.D. Sweeney ◽  
G. Gesner ◽  
G. Smith

An extensive survey of black spruce, Picea mariana (Mill.) B.S.P., in Newfoundland in 1978 disclosed that up to 50% of the old cones remaining on the trees were damaged by the deathwatch cone beetle, Ernobius bicolor White (Schooley 1983; White 1983). This beetle infests black spruce cones produced in the previous year's growing season and also damages cones in storage. Eggs are deposited between the scales and larvae feed within the cone and pupate in the fall or the following spring; their feeding can reduce extracted seed yields by one-half (Schooley 1983).


1992 ◽  
Vol 70 (9) ◽  
pp. 1754-1757 ◽  
Author(s):  
J. A. Johnson ◽  
N. J. Whitney

Endophytic fungi were isolated from black spruce (Picea mariana (Mill.) BSP) dormant buds and needles of four age-classes. Only one isolate was obtained from 400 buds. A total of 914 isolates were obtained from the needles. With increasing needle age the rate of colonization increased between current-year and 3-year-old needles from 4 to 90%, respectively. The needle segment attached to the twig was colonized more often (p < 0.05) than other segments overall and for 6 of the 11 taxa isolated. The first endophyte from current-year needles was isolated on July 14, 1988, but endophytes were obtained from needles of the other age-classes (1, 2, and 3 years) on all sampling dates between June 10 and September 16, 1988. Key words: endophyte, Picea mariana, dormand buds, needles.


1999 ◽  
Vol 29 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Raynald Paquin ◽  
Hank A Margolis ◽  
René Doucet ◽  
Marie R Coyea

Growth and physiology of layers versus naturally established seedlings of boreal black spruce (Picea mariana (Mill.) BSP) were compared 15 years after a cutover in Quebec. During the first 8 years, height growth of seedlings was greater than that of layers, averaging 10.4 and 7.0 cm/year, respectively. For the last 5 years, annual height growth of layers and seedlings did not differ (25 cm/year; p > 0.05). Over the entire 15-year period, total height growth of seedlings (251 cm) was greater than that of layers (220 cm), although total height did not differ (p > 0.05) over the last 6 years. During the 15th growing season, there were no differences (p > 0.05) for predawn shoot water potential, stomatal conductance, net photosynthesis, intercellular to ambient CO2 ratio, water use efficiency, and hydraulic conductance between layers and seedlings. For diurnal shoot water potential, seedlings showed slightly less stress than layers on two of the four sampling dates. Thus, in the first few years following the cutover, the slower growth observed for layers indicated that they had a longer acclimation period following the cutover. Afterwards, similar height growth, total height, and physiological characteristics of the two regeneration types indicated that layers can perform as well as naturally established seedlings.


HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1071b-1071
Author(s):  
Daniel Drost ◽  
Darlene Wilcox-Lee ◽  
Richard Zobel

Published data on the spatial patterns and periodicity of root growth in asparagus are limited. During the 1989 growing season growth and distribution of both fleshy and fibrous roots were monitored in a 7 year old asparagus planting. Soil cores were removed at 15 cm intervals to a depth of 90 cm at 40 and 80 cm from the plants in asparagus beds which had been maintained under conventional (CT) and no-till (NT) production systems. Fleshy and fine roots were separated from the soil and root length densities calculated. Harvests began in late March and continued at three week intervals until early November. Fine root growth was greater in the NT than CT in all depths and at both locations in March. Greatest lengths of fine roots were at the 15-60 cm depths for both CT and NT. This pattern was consistent throughout the season. Fine root lengths decreased by one half by the middle of the year (July) and remained at those levels until the last harvest (Nov). Fleshy root lengths were more variable, however NT generally had greater lengths than CT. Greatest length of fleshy roots were located in the 15-60 cm depths for both CT and NT treatments. Few fleshy roots were found below the 60 cm depth.


1964 ◽  
Vol 40 (2) ◽  
pp. 169-174 ◽  
Author(s):  
J. D. Gagnon

The concentration of nitrogen in current year lateral needles of 122 mature dominant and codominant black spruce trees (Picea mariana Mill.) growing on different site qualities has been studied. Analyses carried out on needles collected at the end of the growing season and within two feet of both the top and base of the crown indicated that samples obtained from either position on the crown can be related to site index or site quality. It seems, therefore, that the concentration of nitrogen in needles from the lower branches is as good a criterion of growth or productivity as that in the needles from the upper branches.


1986 ◽  
Vol 62 (3) ◽  
pp. 170-174 ◽  
Author(s):  
Richard Zarnovican

Baur and Eichhorn recognized mean height as the best site index, and many yield tables were established on the assumption of Eichhorn's empirical law. Nevertheless, many other yield tables invalidate the law. This paper examines the application of Eichhorn's empirical law on black spruce (Picea mariana [Mill.] BSP) yield tables data from Plonsky, Ker, and Vézina and Linteau. Key words: Yield tables.


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