scholarly journals Growth of White Spruce, Picea glauca, Seedlings in Relation to Microenvironmental Conditions in a Forest-Prairie Ecotone of Southwestern Manitoba

2007 ◽  
Vol 121 (2) ◽  
pp. 191 ◽  
Author(s):  
Sophan Chhin ◽  
G. Geoff Wang
Keyword(s):  
Soil Temperature ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Carbon Allocation ◽  
White Spruce ◽  
Height Growth ◽  
Tree Canopy ◽  
Morphological Adaptation ◽  
Southern Limit ◽  
Temperature Conditions

The influence of microenvironmental conditions on the growth performance (i.e., diameter and height growth) of White Spruce [Picea glauca (Moench) Voss] seedlings was examined within three contrasting habitats: White Spruce tree islands, open prairies and Trembling Aspen (Populus tremuloides Michx.) groves. These habitats exist within a disjunct occurrence of White Spruce at its southern limit of distribution in three mixed-grass prairie preserves in the Spruce Woods Provincial Park within the forest-prairie ecotone of southwestern Manitoba. Microenvironmental measurements (i.e., light, temperature, relative humidity, soil moisture) were obtained on 10 sites in each of the three habitats and growth characteristics of 60 White Spruce seedlings were measured in each of three habitats. Higher light and soil temperature conditions occurred within the open prairie. In contrast, lower light and soil temperature conditions occurred under the tree canopy of aspen groves and the northern aspect of spruce islands, which moderated the effect of the dry regional climate. Height growth did not vary significantly among the three habitats. The greater diameter growth and decreased slenderness of White Spruce seedlings in the open versus the shaded habitats appears to be a result of increased photosynthesis at higher light intensity and may also represent a morphological adaptation to withstand the effect of increased wind exposure. The increased slenderness of White Spruce in the shaded habitats appears to be a morphological adaptation of increasing carbon allocation towards height growth and thus maximizing effective competition for light.

The effect of ectomycorrhizae on water relations in aspen (Populus tremuloides) and white spruce (Picea glauca) at low soil temperatures

2002 ◽  
Vol 80 (6) ◽  
pp. 684-689 ◽  
Author(s):  
Simon M Landhäusser ◽  
Tawfik M Muhsin ◽  
Janusz J Zwiazek
Keyword(s):  
Stomatal Conductance ◽  
Soil Temperature ◽  
Water Uptake ◽  
Water Relations ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
White Spruce ◽  
Hydraulic Conductance ◽  
Root Hydraulic Conductance ◽  
Soil Temperatures

Low soil temperatures, common during the growing season in northern forests, have the potential to impede plant growth. In this study, water uptake, water relations, and growth characteristics were examined in aspen (Populus tremuloides) and white spruce (Picea glauca) seedlings that were inoculated with ectomycorrhizal fungi and grown at 20°C daytime air temperatures and low soil temperatures of 4°C and 8°C. Mycorrhizal associations had little effect on root and shoot biomass at both soil temperatures. Root hydraulic conductance (Kr) was higher in both mycorrhizal plant species compared to nonmycorrhizal plants, but there was no soil temperature effect on Kr in either species. Mycorrhizae also increased shoot water potential (Ψw) in Populus tremuloides but had no effect on Ψw in Picea glauca. The increases in Kr and Ψw were not reflected by changes in stomatal conductance (gs) and transpiration rates (E), suggesting that the reduction of water flow in seedlings exposed to low soil temperature was not likely the factor limiting gs in both plant species.Key words: boreal forest, root hydraulic conductance, root growth, stomatal conductance, water uptake.

Effects of shelter and competition on the early growth of planted white spruce (Picea glauca)

1999 ◽  
Vol 29 (7) ◽  
pp. 1002-1014 ◽  
Author(s):  
Arthur Groot
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Light Availability ◽  
White Spruce ◽  
Height Growth ◽  
Northern Ontario ◽  
Vegetation Control ◽  
Clear Cutting ◽  
Canopy Removal ◽  
Second Year

Overstory manipulation and vegetation control treatments were applied at three experimental locations in northern Ontario, Canada, to examine shelter and competition effects on planted white spruce (Picea glauca (Moench) Voss). Overstories were nearly pure trembling aspen (Populus tremuloides Michx.) or aspen-conifer mixedwoods. Overstory treatments included clear-cutting, uniform shelterwood (40% canopy removal), strip shelterwood (widths from 0.5 to 1.0H, where H is the height of dominants), patch shelterwood (diameter about 1.0H), narrow strips (width 0.25H), and intact overstory. Vegetation-control treatments included herbicide and no-herbicide treatments. Second-year seedling growth was poorest under intact overstories and in 0.25H strips, and vegetation control had little effect on growth in this situation. Vegetation control in clearcuts increased seedling diameter but not height growth. In shelterwood treatments, however, vegetation control often increased both diameter and height growth. Greatest diameter tended to occur in clearcuts with vegetation control, whereas greatest height growth tended to occur in shelterwoods with vegetation control. These differing responses likely occur because diameter growth is influenced primarily by light availability, but height growth is additionally affected by other environmental factors. Combining early vegetation control along with shelterwood treatments appears to provide the optimum environment for establishing white spruce.

Radial Growth Decline of White Spruce (Picea glauca) During Hot Summers without Drought: Preliminary Results from a Study Site South of a Boreal Forest Border

2022 ◽  
Author(s):  
Andrei Lapenis ◽  
George Robinson ◽  
Gregory B. Lawrence
Keyword(s):  
New York ◽  
Boreal Forest ◽  
Picea Glauca ◽  
Radial Growth ◽  
Summer Precipitation ◽  
White Spruce ◽  
Southern Limit ◽  
Central New York ◽  
Growth Decline ◽  
Hot Days

Here we investigate the possible<sup></sup> future response of white spruce (Picea glauca) to a warmer climate by studying trees planted 90 years ago near the southern limit of their climate tolerance in central New York, 300 km south of the boreal forest where this species is prevalent. We employed high-frequency recording dendrometers to determine radial growth phenology of six mature white spruce trees during 2013-2017. Results demonstrate significant reductions in the length of radial growth periods inversely proportional to the number of hot days with air temperature exceeding 30 oC. During years with very hot summers, the start of radial growth began about 3 days earlier than the 2013-2017 average. However, in those same years the end of radial growth was also about 17 days earlier resulting in a shorter (70 versus 100 day), radial growth season. Abundant (350-500 mm) summer precipitation, which resulted in soil moisture values of 20-30% allowed us to dismiss drought as a factor. Instead, a likely cause of reduced radial growth was mean temperature that exceeded daily average of 30<sup> o</sup>C that lead to photoinhibition.

scholarly journals Application of Nursery Testing in Long-Term White Spruce Improvement Programs

2007 ◽  
Vol 24 (4) ◽  
pp. 296-300 ◽  
Author(s):  
Yuhui Weng ◽  
Kathy Tosh ◽  
Yill Sung Park ◽  
Michele S. Fullarton
Keyword(s):  
Picea Glauca ◽  
Genetic Correlations ◽  
Field Tests ◽  
Field Performance ◽  
White Spruce ◽  
Height Growth ◽  
Positive Assortative Mating ◽  
The Family ◽  
Improvement Programs

Abstract Polycross-pollinated white spruce (Picea glauca [Moench] Voss) families were evaluated in field and retrospective nursery tests in 1989, 1991, and 1992, respectively. Height growth was measured at age 10 for the field tests and at ages 1 to 6 for the retrospective nursery tests. Except for a few cases, the family mean correlations between nursery and field heights were significant for the 1989 and 1992 series, and their corresponding genetic correlations ranged from low to medium (from 0.37 to 0.74). Because of heavy noncrop competition, height growth in the 1991 nursery series showed consistently lower heritabilities and correlations with field performance compared with those of the other two series. Early nursery selection by theoretical prediction was generally efficient for the 1989 and 1992 series. Rank classification analysis indicated that application of early nursery selection should be used with caution for identifying elite families but could be used to cull inferior families or clones, apply multiple-stage selection, or perform positive assortative mating.

scholarly journals Taper Equations for Five Major Commercial Tree Species in Manitoba, Canada

2007 ◽  
Vol 22 (3) ◽  
pp. 163-170 ◽  
Author(s):  
Ryan J. Klos ◽  
G. Geoff Wang ◽  
Qing-Lai Dang ◽  
Ed W. East
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
White Spruce ◽  
Jack Pine ◽  
Volume Estimation ◽  
Trembling Aspen ◽  
Stem Form ◽  
Taper Equation ◽  
Taper Equations

Abstract Kozak's variable exponent taper equation was fitted for balsam poplar (Populus balsamifera L.), trembling aspen (Populus tremuloides Michx.), white spruce (Picea glauca [Moench] Voss), black spruce (Picea mariana [Mill.] B.S.P.), and jack pine (Pinus banksiana Lamb.) in Manitoba. Stem taper variability between two ecozones (i.e., Boreal Shield and Boreal Plains) were tested using the F-test. Regional differences were observed for trembling aspen, white spruce, and jack pine, and for those species, separate ecozone-specific taper equations were developed. However, the gross total volume estimates using the ecozone-specific equations were different from those of the provincial equations by only 2 percent. Although the regional difference in stem form was marginal within a province, a difference of approximately 7 percent of gross total volume estimation was found when our provincial taper equations were compared with those developed in Alberta and Saskatchewan. These results suggest that stem form variation increases with spatial scale and that a single taper equation for each species may be sufficient for each province.

Within-tree patterns of wood stiffness for white spruce (Picea glauca) and trembling aspen (Populus tremuloides)

2014 ◽  
Vol 44 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Derek F. Sattler ◽  
Philip G. Comeau ◽  
Alexis Achim
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Radial Growth ◽  
Tree Height ◽  
White Spruce ◽  
Vertical Position ◽  
Trembling Aspen ◽  
Mixed Effect ◽  
Cambial Age ◽  
Rate Of Increase

Radial patterns of modulus of elasticity (MOE) were examined for white spruce (Picea glauca (Moench) Voss) and trembling aspen (Populus tremuoides Michx.) from 19 mature, uneven-aged stands in the boreal mixedwood region of northern Alberta, Canada. The main objectives were to (1) evaluate the relationship between pith-to-bark changes in MOE and cambial age or distance from pith; (2) develop species-specific models to predict pith-to-bark changes in MOE; and (3) to test the influences of radial growth, relative vertical height, and tree slenderness (tree height/DBH) on MOE. For both species, cambial age was selected as the best explanatory variable with which to build pith-to-bark models of MOE. For white spruce and trembling aspen, the final nonlinear mixed-effect models indicated that an augmented rate of increase in MOE occurred with increasing vertical position within the tree. For white spruce trees, radial growth and slenderness were found to positively influence maximum estimated MOE. For trembling aspen, there was no apparent effect of vertical position or radial growth on maximum MOE. The results shed light on potential drivers of radial patterns of MOE and will be useful in guiding silvicultural prescriptions.

Are mixtures of aspen and white spruce more productive than single species stands?

1999 ◽  
Vol 75 (3) ◽  
pp. 505-513 ◽  
Author(s):  
Rongzhou Man ◽  
Victor J. Lieffers
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
White Spruce ◽  
Single Species ◽  
Physical Separation ◽  
Soil Resource ◽  
Mixedwood Forests ◽  
Environmental Extremes ◽  
Spruce Stands ◽  
Boreal Mixedwoods

In boreal mixedwood forests, aspen (Populus tremuloides) and white spruce (Picea glauca) commonly grow in mixture. These species may avoid competition through differential shade tolerance, physical separation of canopies, phenological differences, successional separation, and differences in soil resource utilization. Aspen may also be able to positively affect the growth of white spruce by improving litter decomposition and nutrient cycling rates, controlling grass and shrub competition, ameliorating environmental extremes, and reducing pest attack. These positive relationships likely make mixed-species stands more productive than pure stands of the same species. The evidence regarding the productivity of pure versus mixed aspen/white spruce stands in natural unmanaged forests is examined in this paper. Key words: Tree mixture; productivity; boreal mixedwoods; aspen; white spruce

Dynamics of regeneration gaps following harvest of aspen stands

2006 ◽  
Vol 36 (7) ◽  
pp. 1818-1833 ◽  
Author(s):  
Daniel A MacIsaac ◽  
Philip G Comeau ◽  
S Ellen Macdonald
Keyword(s):  
Spatial Heterogeneity ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Natural Disturbance ◽  
White Spruce ◽  
Deciduous Trees ◽  
Trembling Aspen ◽  
Calamagrostis Canadensis ◽  
Edaphic Conditions ◽  
Over Time

This study assessed the dynamics of gap development in postharvest regeneration in five stands in northwestern Alberta dominated by trembling aspen (Populus tremuloides Michx.). The pattern of gap development over time was determined from analysis of air photographs taken preharvest and 1, 4, 10, and 12 years postharvest. The area of each stand covered by gaps increased after harvest because of the addition of harvest-related gaps over and above those that had been present prior to harvest. The blocks we studied had a combined gap area of up to 29% of stand area 12 years postharvest. We measured regeneration characteristics, microsite, soil, light, and browse conditions in 30 aspen regeneration gaps (gaps in regeneration that were not gaps preharvest and were not due to obvious harvest-related disturbance) 14 years following harvest. Although deciduous trees within postharvest regeneration gaps were the same age as those outside (i.e., in a fully stocked matrix of newly established even-aged aspen stems), they were often suppressed, with significantly lower density and growth. Within the 14-year-old postharvest regenerating aspen stands, aspen height varied from 1 to 11 m; this substantial variability appeared to be largely due to the influence of browsing. There was little evidence of ongoing regeneration within postharvest regeneration gaps, indicating that these gaps will probably persist over time. This may impact future deciduous stocking and volume. It is unknown what may have initiated the formation of these gaps, although results suggest that they are not due to edaphic conditions or disease in the preharvest stands. There is evidence that bluejoint (Calamagrostis canadensis (Michx.) Beauv.) cover and browsing are important factors in the maintenance of postharvest regeneration gaps. The spatial heterogeneity resulting from gaps could be advantageous, however, either as part of ecosystem-based management emulating natural disturbance or as a template for mixedwood management, where white spruce (Picea glauca (Moench) Voss) are established in gaps.

The utility of the two-pass harvesting system: an analysis using the ecosystem simulation model FORECAST

2002 ◽  
Vol 32 (6) ◽  
pp. 1071-1079 ◽  
Author(s):  
Clive Welham ◽  
Brad Seely ◽  
Hamish Kimmins
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
White Spruce ◽  
Ecosystem Model ◽  
Yield Potential ◽  
Model Forecast ◽  
Pass System ◽  
System A ◽  
Ecosystem Simulation ◽  
Harvesting Systems

The ecosystem model FORECAST was used to simulate the yield potential in Saskatchewan mixedwoods of the two-pass harvesting system. The simulated two-pass stand consisted of an overstory population of pure trembling aspen (Populus tremuloides Michx.) with a white spruce (Picea glauca (Moench) Voss) understory. The aspen was removed at year 60, and yields of the understory spruce and resprouting aspen were simulated for 80 years thereafter. The two-pass simulations were compared with two simulated conventional harvesting systems. The first system consisted of a single final harvest at year 140. In the second system, a clearcut was conducted at year 60. White spruce was then planted in the subsequent year at 400, 600, or 800 stems/ha, and aspen also permitted to resprout. Growth was then simulated for a further 80 years. FORECAST projections indicated that the two-pass system might be effective for releasing the white spruce understory, achieving at least a twofold gain in spruce volume relative to conventional methods. Furthermore, total volumes exceeded those derived from the unmanaged stand, while second rotation yields of aspen declined with spruce understory density. These simulations suggest the two-pass harvesting system has strong potential as a tool for mixedwood management.

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