scholarly journals The Influence of Stocking and Stand Composition on Productivity of Boreal Trembling Aspen-White Spruce Stands

Forests ◽  
2015 ◽  
Vol 6 (12) ◽  
pp. 4573-4587 ◽  
Author(s):  
Valentín Reyes-Hernández ◽  
Philip Comeau
2012 ◽  
Vol 42 (8) ◽  
pp. 1566-1576 ◽  
Author(s):  
Derek Joseph Lawrence ◽  
N. Luckai ◽  
W.L. Meyer ◽  
C. Shahi ◽  
A.J. Fazekas ◽  
...  

Mixedwood forests of white spruce ( Picea glauca (Moench) Voss) and trembling aspen ( Populus tremuloides Michx.) may possess ecological advantages over monospecific white spruce stands. Belowground competition may be reduced through vertically stratified roots; facilitation of growth may occur in upper soil layers through nutrient-rich trembling aspen litterfall. These effects may incentivize white spruce to preferentially exploit upper soil layers in mixedwood stands, resulting in wider root systems. This research contrasted white spruce fine root (diameter <2 mm) distributions in organic layers of white spruce and mixedwood stands. Research occurred at the Fallingsnow Ecosystem Project site in northwestern Ontario. Eighteen plots represented mixedwood and pure white spruce stands. Trees were mapped; foliage and root samples were collected. Roots were separated by species and scanned to determine length. Simple sequence repeat DNA profiles were determined for all white spruce trees and for 45 white spruce root fragments per plot. Root and tree DNA profiles were matched; corresponding distances were calculated. Most (80%) root fragments were within 3.2 m of tree stems. Root prevalence decreased rapidly with distance. Organic layer pH was significantly less acidic in mixedwood plots, but only in one block. A subtle significant trend towards wider root distributions occurred in mixedwood stands.


1993 ◽  
Vol 23 (6) ◽  
pp. 1233-1239 ◽  
Author(s):  
David Paré ◽  
Keith Van Cleve

Nutrient content and biomass of aboveground annual production, and nutrient content of total aboveground biomass, of 14-year-old assemblages of plants developing on harvested white spruce (Piceaglauca (Moench) Voss) sites were estimated by vegetation harvesting and compared with values previously measured in mature white spruce stands. The aboveground biomass production of 14-year-old regenerating trembling aspen (Populustremuloides Michx.) clumps was 3 times higher than the aboveground production of mature white spruce stands, while the aboveground production of other regenerating communities was lower or equivalent to the production of mature white spruce. However, the nutrient content of aboveground current biomass was greater in all regenerating communities than in mature white spruce stands, except on regenerating sites where the forest floor was absent. The amount of nutrient incorporated in current aboveground biomass was 5 times greater in trembling aspen clumps than in mature white spruce stands. Furthermore, the total N, P, and K content of aboveground vegetation corresponded, in 14-year-old trembling aspen clumps, to a value that ranged from 50 to 109% of the amount found in the aboveground biomass of mature white spruce forests, while this value ranged from 4 to 14% on other regeneration types. Trembling aspen and balsam poplar (Populusbalsamifera L.) both showed the greatest concentrations of N and P in foliar litter fall. These observations suggest that the development of a trembling aspen clump after clear-cutting contributes to the acceleration of nutrient cycling. On the other hand, the development of herbaceous communities during the same period after clear-cutting was accompanied by much lower nutrient cycling rates in the aboveground portion of the vegetation.


1979 ◽  
Vol 9 (4) ◽  
pp. 443-448 ◽  
Author(s):  
D. F. W. Pollard ◽  
C. C. Ying

Newly germinated seedlings of 66 open-pollinated white spruce Piceaglauca (Moench) Voss families from 11 native stands in southeastern Ontario were investigated for responses to declining photoperiod under controlled environments. Amount of height increment (free growth) during a period of declining photoperiod was studied. Variation in duration of free growth was found mostly associated with the family-within-stand component. The stand effect was negligible and decreased as seedlings aged. Lack of stand differentiation suggests that white spruce stands in. southeastern Ontario may have originated from the same base population. High genetic variation at the family level may reflect an adaptive strategy to cope with the extremely variable local climate.


2015 ◽  
Vol 358 ◽  
pp. 98-107 ◽  
Author(s):  
Seung-Il Lee ◽  
John R. Spence ◽  
David W. Langor ◽  
Jaime Pinzon

1954 ◽  
Vol 30 (2) ◽  
pp. 158-182
Author(s):  
I. Kagis

1. A considerable part of the mixed white spruce—trembling aspen stands in Saskatchewan appears to be forming itself in a cyclic process. After a fire, when poplar has established itself, the first wave of spruce comes in; the second follows in about 50 to 70 years. When the trembling aspen thins itself, the crest of the third wave comes and, together with the remaining apsen, the spruce of the first wave starts to deteriorate.2. This cyclic development of such stands seems to provide an opportunity to apply management on the basis of a permanent forest.3. Cutting by diameter limit in such stands results in windthrow and die-off, exceeding the increment of the residual white spruce.4. Crown quality is a decisive factor with white spruce in its response to release in these mixed stands.5. White spruce in these mixed stands responds to release even at the age of 100 years.6. Insufficient regeneration of white spruce in the examined area appears to be due to lack of seed; heavy sod, invasion of shrubs and weeds seem to be main obstacles to regeneration.


2007 ◽  
Vol 22 (3) ◽  
pp. 163-170 ◽  
Author(s):  
Ryan J. Klos ◽  
G. Geoff Wang ◽  
Qing-Lai Dang ◽  
Ed W. East

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.


Ecoscience ◽  
2014 ◽  
Vol 21 (3-4) ◽  
pp. 187-201 ◽  
Author(s):  
Sandra R. Carr ◽  
Nancy Luckai ◽  
Guy R. Larocque ◽  
Douglas E. B. Reid

2014 ◽  
Vol 44 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Derek F. Sattler ◽  
Philip G. Comeau ◽  
Alexis Achim

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.


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