scholarly journals Regeneration of White Spruce Under Aspen Canopies: Seeding, Planting, and Site Preparation

2000 ◽  
Vol 15 (4) ◽  
pp. 177-182 ◽  
Author(s):  
James D. Stewart ◽  
Simon M. Landhäusser ◽  
Kenneth J. Stadt ◽  
Victor J. Lieffers
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Germination Rate ◽  
White Spruce ◽  
Seed Rain ◽  
Growing Seasons ◽  
Significant Difference ◽  
Different Types ◽  
And Control ◽  
Northern Alberta

Abstract This study investigated the establishment and survival of naturally and artificially seeded white spruce (Picea glauca), as well as three sizes of planted white spruce stock, on different types of scarification beneath mature aspen (Populus tremuloides) in northern Alberta. White spruce seed rain, natural and hand-seeded regeneration establishment and survival, and understory vegetation response were monitored for 4 yr on scarified strips (light blading, heavy blading, and ridged) and on undisturbed controls. Despite a heavy seed rain in 1993, seedling establishment on control plots was almost nil. On scarified plots, the number of seeds required to produce a live seedling after 3 growing seasons ranged from 15 to 37 and up to 68 in one site. Most mortality occurred during the summer. Germination rate on the hand-seeded plots ranged from 19 to 28% on the scarified strips. There was no significant difference in survival from seed (15%) after three growing seasons among the three scarification treatments. Survival of planted stock was 98% on scarified strips and 96% on control strips. Diameter growth was least on control plots but was not significantly different among the scarified treatments. In contrast, height increment was greatest on the light blading treatment and differed little among the other two treatments and control. These results suggest that spruce regeneration in aspen forests can be promoted by scarification or underplanting. West. J. Appl. For. 15(4):177–182.

Vegetation management and site preparation effects on 13C isotopic composition in planted white spruce

2001 ◽  
Vol 31 (6) ◽  
pp. 1093-1097 ◽  
Author(s):  
Thomas E Staples ◽  
Ken CJ Van Rees ◽  
J Diane Knight ◽  
C van Kessel
Keyword(s):  
Soil Moisture ◽  
Picea Glauca ◽  
White Spruce ◽  
Vegetation Management ◽  
Site Preparation ◽  
Native Vegetation ◽  
Active Radiation ◽  
Growing Seasons ◽  
Initial Hypothesis ◽  
And Control

Moisture availability is the factor that most commonly influences the discrimination against 13C fixation (Δ) by C3 plants. Therefore, by changing the availability of moisture by way of controlling competing vegetation, Δ in white spruce (Picea glauca (Moench) Voss) seedlings should be affected. The objective of this study was to determine the influence of manual brushing on Δ in white spruce seedlings planted in disc-trenched and control (i.e., no site preparation) microsites. The effects of site preparation and vegetation management on soil moisture, photosynthetically active radiation (PAR), and Δ in white spruce seedlings were evaluated over three growing seasons. Vegetation management increased the amount of PAR reaching seedlings in the control and disc-trenched treatments by removing the shading by native vegetation around each seedling. It appears that the increase in PAR reaching seedlings decreased Δ by increasing the photosynthetic consumption of CO2. Differences in soil available moisture (up to 22%) between control and disc-trenched treatments were not reflected in Δ values, contrary to our initial hypothesis. This may indicate that the site was not moisture limiting. Also, these results underline the complexity and difficulty of determining the controlling mechanisms by which Δ is affected.

Nitrogen competition using 15N between early successional plants and planted white spruce seedlings

1999 ◽  
Vol 29 (8) ◽  
pp. 1282-1289 ◽  
Author(s):  
Thomas E Staples ◽  
Ken CJ Van Rees ◽  
Chris van Kessel
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
N Uptake ◽  
Growing Season ◽  
White Spruce ◽  
Fertilizer N ◽  
Growing Seasons ◽  
Epilobium Angustifolium ◽  
Use Efficiency ◽  
Fertilizer N Uptake

The ability of noncrop plants to compete with white spruce (Picea glauca (Moench) Voss) seedlings for applied fertilizer N is not well understood. Therefore, the objective of this study was to examine the efficacy of fertilizer N uptake using 15N by planted white spruce seedlings and understory vegetation. Double 15N-labeled NH4NO3 was broadcast in 1-m2plots for control, disc-trenched, and disc-trenched + manual brushing treatments. The fate of applied 15N in white spruce and noncrop plants was determined at the end of the first two growing seasons. The major competitors for fertilizer 15N were Populus tremuloides Michx. and grasses during the first growing season, and Populus tremuloides, Epilobium angustifolium L., and Achillea millefolium L. during the second growing season. Disc-trenching plus manual brushing significantly increased the fertilizer use efficiency of white spruce seedlings by limiting competition; however, <1% of the applied fertilizer 15N was utilized by the spruce seedlings after two growing seasons. The ability of competing vegetation to absorb broadcast fertilizer N suggests that alternative fertilizer types and placements be investigated to increase N uptake by white spruce seedlings planted in the boreal mixedwood forest.

Microfungus communities of white spruce and trembling aspen logs at different stages of decay in disturbed and undisturbed sites in the boreal mixedwood region of Alberta

2001 ◽  
Vol 79 (1) ◽  
pp. 76-92 ◽  
Author(s):  
Trevor C Lumley ◽  
L Dennis Gignac ◽  
Randolph S Currah
Keyword(s):  
Species Richness ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Trichoderma Viride ◽  
White Spruce ◽  
Fungal Species ◽  
Trembling Aspen ◽  
Mitosporic Fungi ◽  
Northern Alberta ◽  
Isolated Species

Fallen logs of trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench) Voss) at various stages of decomposition were sampled from undisturbed and 1-, 14-, and 28-year-old post-fire and post-harvest sites in northern Alberta and studied for differences in the associated microfungus communities. Wood samples were plated directly onto each of six different media and, from these, fungal species were identified and enumerated over a 24-month period. Approximately 10 000 isolates were obtained, representing 292 species of filamentous microfungi, including 41 ascomycetes, 29 zygomycetes, and 222 mitosporic fungi. The most commonly isolated species were Trichoderma viride (Gray) Pers., Rhinocladiella atrovirens Nannf., Penicillium pinophilum Hedgcock, and Mortierella ramanniana (Moller) Linnem. Cluster analysis and ordination of microfungus communities in logs showed that the tree species of the log had the greatest influence on the species composition of communities. Fungus community composition was also correlated with the stage of decomposition. Species richness was highest in logs from undisturbed sites and lowest in logs from the most recently disturbed sites. Species diversity (Shannon-Weaver) was only slightly higher at undisturbed sites than at disturbed sites. The most significant environmental factor was log moisture, which increased proportionately with stage of decomposition and was significantly correlated with climatic factors.Key words: ecology, fungi, ordination, succession, species richness, diversity.

scholarly journals Growing Space Management in Boreal Mixedwood Forests: 11-Year Results

2011 ◽  
Vol 26 (2) ◽  
pp. 82-90 ◽  
Author(s):  
Richard D. Kabzems ◽  
George Harper ◽  
Peter Fielder
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Light Availability ◽  
White Spruce ◽  
Tree Level ◽  
Mixed Stands ◽  
Individual Tree ◽  
Space Management ◽  
Growing Seasons ◽  
The Individual

Abstract Managing boreal mixed stands of trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca [Moench] Voss) is more likely to sustain a diversity of values and has the potential to increase productivity at both the site and landscape levels compared with pure broadleaf or conifer management. In this study, we examine growth of white spruce and aspen after 11 growing seasons over a range of aspen densities created by spot and broadcast treatment of broadleaves using manual and chemical means, aspen spacing, and an untreated control. Results indicate that survival and growth of both spruce and aspen were similar across the range of treatments. Spruce groundline diameter was greater, and height to groundline diameter ratio was lower, for the treatments in which aspen was chemically controlled or uniformly spaced compared with the control. Light measurements at the individual tree level suggested that increased light availability improved white spruce diameter growth. Spruce height growth did not vary by treatment. The status of these experimental mixedwoods was compared with current conifer and mixedwood regeneration evaluations, as well as the preharvest composition of the original stand. After 11 growing seasons, growth of aspen and white spruce indicated that opportunities exist to further modify aspen density to enhance treatment longevity and effectiveness to produce a greater range of boreal mixedwood stand types.

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.

Ectomycorrhizal fungal communities of nursery-inoculated seedlings outplanted on clear-cut sites in northern Alberta

2006 ◽  
Vol 36 (7) ◽  
pp. 1684-1694 ◽  
Author(s):  
André Gagné ◽  
Jean-Luc Jany ◽  
Jean Bousquet ◽  
Damase P Khasa
Keyword(s):  
Ssr Markers ◽  
Ectomycorrhizal Fungi ◽  
Picea Glauca ◽  
Pinus Contorta ◽  
Morphological Characterization ◽  
Fungal Communities ◽  
Volume Index ◽  
Clear Cut ◽  
And Control ◽  
Northern Alberta

Seedlings from three conifer species (Pinus contorta Doug. ex Loud. var. latifolia Englem., Picea glauca (Moench) Voss, and Picea mariana (Mill.) BSP) were planted on two clear-cut sites in Alberta, Canada, after inoculation in the nursery with strains of six different ectomycorrhizal species (Hebeloma longicaudum, Laccaria bicolor,Paxillus involutus,Pisolithus tinctorius,Rhizopogon vinicolor, and Suillus tomentosus). Five and 6 years after planting, morphological characterization and molecular typing techniques (internal transcribed spacer – restriction fragment length polymorphism (ITS-RFLP) and simple sequence repeat (SSR) markers) were used to identify the ectomycorrhizal fungal communities and to assess the occurrence of the inoculated ectomycorrhizal fungi on host roots. Ectomy corrhi zae recovered from the roots of the planted trees on each of the two sites showed little diversity, with a total of 16 and 19 ITS-RFLP patterns corresponding to 11 and 13 ectomycorrhizal taxa, respectively. The most abundant ectomycorrhizal fungi found on colonized roots were ascomycetes and the widespread basidiomycete Amphinema byssoides. Amongst the six introduced fungal strains, only L. bicolor UAMH 8232 was detected on one site after 5 and 6 years, as determined using six SSR markers. Although not detected after 5 years, some of the introduced strains might have had a positive effect on the early growth of the trees before their replacement by competing species, because significant differences in plot volume index were detected between inoculation and control treatments.

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.

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