CO2 stimulation and response mechanisms vary with light supply in boreal conifers

2020 ◽  
Author(s):  
Qing-Lai Dang ◽  
Jacob Marfo ◽  
Fengguo Du ◽  
Rongzhou Man ◽  
Sahari Inoue
Keyword(s):  
Elevated Co2 ◽  
Picea Glauca ◽  
Boreal Forests ◽  
Black Spruce ◽  
Net Photosynthesis ◽  
Growing Season ◽  
White Spruce ◽  
Light Supply ◽  
Ecophysiological Responses ◽  
Light Effects

Abstract Aims Black spruce (Picea mariana [Mill.] B.S.P.) and white spruce (Picea glauca [Moench] Voss.) are congeneric species. Both are moderately shade tolerant and widely distributed across North American boreal forests. Methods To understand light effects on their ecophysiological responses to elevated [CO2], 1-year old seedlings were exposed to 360 and 720 µmol mol -1 [CO2] at three light conditions (100, 50 and 30% of full light in the greenhouse). Foliar gas exchanges were measured in the mid- and late-growing season. Important Findings Elevated [CO2] increased net photosynthesis (Pn) and photosynthetic water use efficiency, but it reduced stomatal conductance and transpiration. The stimulation of photosynthesis by CO2 was greatest at 50% light and smallest at 100%. Photosynthesis, maximum carboxylation rate (Vcmax) and light saturated rate of electron transport (Jmax) all decreased with decreasing light. Elevated [CO2] significantly reduced Vcmax across all light treatments and both species in mid-growing season. However, the effect of elevated [CO2] became insignificant at 30% light later in the growing season, with the response being greater in black spruce than in white spruce. Elevated [CO2] also reduced Jmax in white spruce in both measurements while the effect became insignificant at 30% light later in the growing season. However, the effect on black spruce varied with time. Elevated [CO2] reduced Jmax in black spruce in mid-growing season in all light treatments and the effect became insignificant at 30% light later in the growing season, while it increased Jmax later in the season at 100% and 50% light. These results suggest that both species benefited from elevated CO2, and that the responses varied with light supply, such that the response was primarily physiological at 100% and 50% light, while it was primarily morphological at 30% light.

scholarly journals Cold hardiness of white spruce, black spruce, jack pine, and lodgepole pine needles during dehardening

2017 ◽  
Vol 47 (8) ◽  
pp. 1116-1122 ◽  
Author(s):  
Rongzhou Man ◽  
Pengxin Lu ◽  
Qing-Lai Dang
Keyword(s):  
Picea Glauca ◽  
Pinus Banksiana ◽  
Cold Hardiness ◽  
Black Spruce ◽  
Lodgepole Pine ◽  
White Spruce ◽  
Visual Assessment ◽  
Jack Pine ◽  
Pine Needles ◽  
Late Winter

Conifer winter damage results primarily from loss of cold hardiness during unseasonably warm days in late winter and early spring, and such damage may increase in frequency and severity under a warming climate. In this study, the dehardening dynamics of lodgepole pine (Pinus contorta Dougl. ex. Loud), jack pine (Pinus banksiana Lamb.), white spruce (Picea glauca (Moench) Voss), and black spruce (Picea mariana (Mill.) B.S.P.) were examined in relation to thermal accumulation during artificial dehardening in winter (December) and spring (March) using relative electrolyte leakage and visual assessment of pine needles and spruce shoots. Results indicated that all four species dehardened at a similar rate and to a similar extent, despite considerably different thermal accumulation requirements. Spring dehardening was comparatively faster, with black spruce slightly hardier than the other conifers at the late stage of spring dehardening. The difference, however, was relatively small and did not afford black spruce significant protection during seedling freezing tests prior to budbreak in late March and early May. The dehardening curves and models developed in this study may serve as a tool to predict cold hardiness by temperature and to understand the potential risks of conifer cold injury during warming–freezing events prior to budbreak.

scholarly journals Splitting in Fire-Killed Trees in the Boreal Forest of Alberta

2003 ◽  
Vol 20 (4) ◽  
pp. 167-174
Author(s):  
Nobutaka Nakamura ◽  
Paul M. Woodard ◽  
Lars Bach
Keyword(s):  
Boreal Forest ◽  
Boreal Forests ◽  
Black Spruce ◽  
Lodgepole Pine ◽  
White Spruce ◽  
Balsam Fir ◽  
Crown Fire ◽  
In Fire ◽  
Solar Angle

Abstract Tree boles in the boreal forests of Alberta, Canada will split once killed by a stand-replacing crown fire. A total of 1,485 fire-killed trees were sampled, 1 yr after burning, in 23 plots in 14 widely separated stands within a 370,000 ha fire. Sampling occurred in the Upper and Lower Foothills natural subregions. The frequency of splitting varied by species but averaged 41% for all species. The order in the frequency of splitting was balsam fir, black spruce, white spruce and lodgepole pine. The type of splitting (straight, spiral, or multiple) varied by species, as did the position of the split on the tree bole. Aspect or solar angle was not statistically related to the type or occurrence of splitting.

scholarly journals Site-index Curve Shape in Spruce

1969 ◽  
Vol 45 (3) ◽  
pp. 184-186 ◽  
Author(s):  
L. Heger
Keyword(s):  
Picea Glauca ◽  
Black Spruce ◽  
White Spruce ◽  
Site Index ◽  
Absolute Difference ◽  
Curve Shape ◽  
Breast Height ◽  
Maximum Absolute Difference ◽  
Site Index Curve ◽  
Index Curve

Sets of site-index curves were prepared from stem analyses of white spruce (Picea glauca (Moench) Voss) and black spruce (P. mariana (Mill.) BSP.) from various regions in the boreal forest of Canada. Ordinates of the site-index curves, computed for 5-year breast-height age intervals up to 75 years, and for 10-foot site-index intervals up to 70 feet, were compared within the species for the same values of site index and age. For breast-height ages below 55 years and for site index below 70 feet, the maximum absolute difference among the ordinates did not exceed 2.0 feet in white spruce, and 1.6 feet in black spruce; the corresponding average deviations were 0.75 and 0.80 feet. For breast-height ages above 55 years, these differences increased with age and, at 75 years, reached 8.8 feet in white spruce, and 3.8 feet in black spruce; the corresponding average deviations were 4.40 and 1.53 feet.

Black and White Spruce Plantings in Minnesota: Container vs Bareroot Stock and Fall vs Spring Planting

1983 ◽  
Vol 59 (4) ◽  
pp. 189-191 ◽  
Author(s):  
A. A. Alm
Keyword(s):  
Picea Mariana ◽  
Picea Glauca ◽  
Black Spruce ◽  
White Spruce ◽  
Height Growth ◽  
Artificial Regeneration ◽  
Black And White ◽  
Four Seasons ◽  
Spring Planting ◽  
Better Than

Black spruce (Picea mariana (Mill.) B.S.P.) and white spruce (Picea glauca (Moench) Voss) styrob-lock and paperpot and 3-0 and 2-2 seedlings were planted spring and fall. After four seasons of growth the container seedlings had survival and height growth as good or better than the nursery seedlings. There were no differences in performance between the two container systems. The 2-2 stock generally had better survival than the 3-0 stock. Survival of fall-planted stock was equal to or better than that of the spring-planted stock. Key words: white spruce, black spruce, styroplugs, paper pots, seedlings, transplants, artificial regeneration, fall vs spring planting

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

Comparison of growth and physiology of layers and naturally established seedlings of black spruce in a boreal cutover in Quebec

1999 ◽  
Vol 29 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Raynald Paquin ◽  
Hank A Margolis ◽  
René Doucet ◽  
Marie R Coyea
Keyword(s):  
Water Potential ◽  
Picea Mariana ◽  
Black Spruce ◽  
Net Photosynthesis ◽  
Growing Season ◽  
Height Growth ◽  
Total Height ◽  
Acclimation Period ◽  
Use Efficiency ◽  
Growth Of Seedlings

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.

Growth and Morphology of Black Spruce, Jack Pine, and White Spruce Container Seedlings in Northern Ontario

1995 ◽  
Vol 12 (2) ◽  
pp. 69-74
Author(s):  
Anneli Jalkanen
Keyword(s):  
Shoot Growth ◽  
Black Spruce ◽  
Growing Season ◽  
White Spruce ◽  
Dry Mass ◽  
Jack Pine ◽  
Northern Ontario ◽  
Morphological Attributes ◽  
Crop Development ◽  
In The Beginning

Abstract The development of morphological attributes of containerized seedlings during the growing season was studied in eight crops from three nurseries in Northern Ontario, including four black spruce crops, three jack pine crops, and one white spruce crop. The variability was proportionally largest in root and shoot dry mass, followed by height and diameter. During seedling growth, proportionally the variability of size did not seem to increase. In absolute scale, however, differences between individual seedlings increased more than differences between seedling trays, possibly due to competition between individuals. Height and shoot growth were greater in the beginning of the growing season, and diameter and root growth were greater toward the end. In comparison to standards, the balance between morphological attributes (height/diameter, shoot/root) was usually acceptable, and usually independent of seedling size. The easiest way of monitoring crop development is to take seedling samples at regular intervals and to construct a growth progression curve for seedling height, if diameter growth reaches acceptable level. Care should be taken that the height of seedlings does not increase too much at the expense of diameter and root development in the larger crops. To monitor this, height-diameter ratios and shoot-root ratios might be measured a couple of times during the growing season to take corrective action if necessary. North. J. Appl. For. 12(2):69-74.

Growth, physiology, and leachate losses in Picea glauca seedlings (1+0) grown in air-slit containers under different irrigation regimes

2001 ◽  
Vol 31 (11) ◽  
pp. 1968-1980 ◽  
Author(s):  
Mohammed Lamhamedi ◽  
Gil Lambany ◽  
Hank Margolis ◽  
Mario Renaud ◽  
Linda Veilleux ◽  
...  
Keyword(s):  
Water Content ◽  
Picea Glauca ◽  
Net Photosynthesis ◽  
Growing Season ◽  
Root Surface ◽  
Time Domain Reflectometry ◽  
Nutrient Contents ◽  
Growth Physiology ◽  
Irrigation Regimes ◽  
Lower Height

In production tunnels, time domain reflectometry (TDR) was used to manage irrigation and leaching by controlling water content in the rhizosphere of air-slit containerized white spruce (Picea glauca (Moench) Voss) seedlings (1+0). Seedlings were exposed to four irrigation regimes (v/v: IR-60%, IR-45%, IR-30%, and IR-15%) during the first growing season to assess IR effects on growth, gas exchange, nutrient uptake, carbohydrates, root architecture, and leaching. In the province of Quebec, seedling producers generally maintain a high substrate water content (>50%, v/v) during all growth phases. The accuracy and feasibility of using TDR to decrease irrigation without affecting the material attributes of the seedlings at the end of the first growing season was confirmed. However, seedlings grown under IR-15% had significantly lower height, root collar diameter, shoot and root dry masses, root surface, root length, net photosynthesis, and nutrient contents than seedlings grown under IR-30%, IR-45%, and IR-60%. In comparison with IR-30% and IR-45%, the application of IR-60% produced no increase in shoot or root growth, mineral nutrition, and carbohydrates. Seedlings grown under IR-15%, IR-30%, and IR-45% used approximately 28, 37, and 46%, respectively, of the amount of water applied under IR-60%. Nutrient losses including anions and cations under IR-60% were higher in comparison with the other IRs. Maintaining a water content in the rhizosphere that changes with the stage of seedling development is suggested to optimize growth and to avoid excess irrigation and leaching.

Somatic embryo maturation, germination, and soil establishment of plants of black and white spruce (Picea mariana and Picea glauca)

1990 ◽  
Vol 68 (12) ◽  
pp. 2583-2589 ◽  
Author(s):  
S. M. Attree ◽  
T. E. Tautorus ◽  
D. I. Dunstan ◽  
L. C. Fowke
Keyword(s):  
Abscisic Acid ◽  
Somatic Embryo ◽  
Picea Mariana ◽  
Picea Glauca ◽  
Black Spruce ◽  
White Spruce ◽  
Embryo Maturation ◽  
Black And White ◽  
Somatic Embryo Maturation

Somatic embryo maturation, germination, and soil establishment frequencies were compared for two conifer species, white and black spruce (Picea glauca and Picea mariana). The comparison of the two species regenerated and established in soil under the same conditions showed black spruce to be the most responsive. Shorter exposure times to 32 μM abscisic acid were not as effective as maturation on a medium containing 16 μM abscisic acid for 28 days. This gave similar maturation frequencies for the two species (6–8%), and germination frequencies of 64% for white spruce and over 73% for black spruce. Over 1800 black and white spruce plantlets were recovered, and more than 400 were transferred from in vitro to nonsterile conditions. Sixty percent (160) of the black spruce plantlets survived transfer and continued to grow vigorously. By comparison only 18% (29) of the white spruce plantlets survived, and half of these rapidly produced dormant buds and underwent no further shoot growth. White spruce plants that did not produce dormant buds grew vigorously. These results indicate that there are large differences in the ability of these closely related species to respond to plantlet establishment following regeneration from somatic embryos, and that black spruce is highly responsive to micropropagation by this method. Key words: Picea glauca, Picea mariana, somatic embryogenesis, maturation, germination, soil establishment.

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