scholarly journals Response of White Spruce Plantation to Three Levels of Thinning from Below 1958-1978

1980 ◽  
Vol 56 (1) ◽  
pp. 21-27 ◽  
Author(s):  
W. M. Stiell

In 1958 a thinning experiment to examine the relation of stand growth of white spruce (Picea glauca (Moench) Voss) to density of residual growing stock was established at the Petawawa national Forestry Institute in a 33-year-old plantation growing on a sandy old-field site. A treatment series consisted of sample plots thinned from below to basal area levels of 18.4, 25.3 and 32.1 m2/ha, together with unthinned plots serving as controls. Two such replicates were established. The plots were remeasured and thinned again to the prescribed basal areas in 1968 and 1978. Diameter growth and form quotient were clearly related to degree of thinning. Volume growth was reduced at the lowest residual basal area. The untreated plots contained the highest volume in 1978 but mortality had reduced their total production of merchantable wood by about 10% compared with the thinnings plus standing crop of the two lighter treatments. Thinning to leave a basal area in the range of about 22 to 35 m2/ha should yield 11 to 60 m3/ha of merchantable wood, depending on plantation age and intensity of cut, without reducing stand growth.

2005 ◽  
Vol 22 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Daniel W. Gilmore ◽  
Timothy C. O'Brien ◽  
Howard M. Hoganson

Abstract The Langsaeter hypothesis states, “The total production of cubic volume by a stand of given age and composition on a given site is, for all practical purposes, constant and optimum for a wide range of density of stocking. It can be decreased, but not increased, by altering the amount of growing stock to levels outside this range.” We used a multistep approach to test this hypothesis in a 46-year-old red pine plantation growing on a site of moderate quality in northern Minnesota. First, we used stem analysis data to construct tree-level red pine volume equations and compared them to existing equations. We then calculated stand-level volume. Doing this allowed us to evaluate the performance of two stand-level volume prediction equations, a growth and yield spreadsheet package, and a computer simulation model using 10-year pre- and post-thinning measurements. Tree volume prediction equations were similar to existing equations. For 10-year projections, the stand-level volume prediction equations and growth projection models provided volume estimates within 10% of actual volumes on average. Ten-year post-thinning measurements showed that a geometric, strip thinning to 100 ft2 of basal area resulted in a 40% volume gain, a crown thinning to 125 ft2 of basal area a 35% volume gain, and a low thinning to 140 ft2 of basal area a 30% volume gain, while an unharvested control had a 22% gain in volume relative to residual stand volumes. Although we found the 10-year volume growth varied less than 1 cord ac−1 between residual growing stock volumes retained in this study, we do not have strong evidence to support the Langsaeter hypothesis for red pine. North. J. Appl. For. 22(1):19–26.


2003 ◽  
Vol 33 (10) ◽  
pp. 1962-1973 ◽  
Author(s):  
Philip G Comeau ◽  
Jian R Wang ◽  
Tony Letchford

Five years after spacing a young, 11 m tall paper birch (Betula papyrifera Marsh.) stand, we examine relationships between growth of understory white spruce (Picea glauca (Moench) Voss), subalpine fir (Abies lasiocarpa (Hook.) Nutt.), and level of birch retention. Our objectives were to evaluate the effectiveness of selected measures of competition for estimating the effects of the residual birch and to evaluate the influence of residual birch densities on growth responses of naturally regenerated subalpine fir and white spruce. Basal area of Scouler willow (Salix scouler iana Barratt) and birch were found to effectively predict light transmittance (diffuse noninterceptance). The best models for predicting 4-year volume growth of subalpine fir and white spruce incorporate initial crown volume of the subject trees and transmittance as independent variables. Lorimer's index and Hegyi's index gave similar results to those obtained using basal area and transmittance, suggesting that there is little benefit in including measurements of proximity in a competition index. For both species, the correlation between basal area increment and light was substantially stronger than observed for volume increment. However, height increment of both subalpine fir and spruce was only weakly correlated with measured light levels. The ratio of height increment to volume increment decreased with both increasing initial height and transmittance for subalpine fir and white spruce.


1991 ◽  
Vol 15 (1) ◽  
pp. 22-27
Author(s):  
Terry R. Clason

Abstract A hardwood suppression treatment applied to a 7-year-old, loblolly pine (Pinus taeda L.) plantation enhanced projected productivity through a 35-year rotation that included three commercial thinnings. By age 22, growth data showed that hardwood removal treatments had larger pines and smaller hardwoods than check treatments. Fifteen-year pine basal area and merchantable volume growth on hardwood removal plots exceeded the check plots by 25 and 27%. Projected growth between ages 22 and 35 indicated that 28 years after early hardwood removal thinned plantation merchantable volume yields improved by 840 ft³ per acre. South. J. Appl. For. 15(1):22-27.


1999 ◽  
Vol 29 (7) ◽  
pp. 993-1001 ◽  
Author(s):  
E C Cole ◽  
M Newton ◽  
A Youngblood

The current spruce bark beetle (Dendroctonus rufipennis Kirby) epidemic in interior Alaska is leaving large expanses of dead spruce with little spruce regeneration. Many of these areas are habitat for moose (Alces alces). To establish spruce regeneration and improve browse production for moose, paper birch (Betula papyrifera Marsh), willow (Salix spp.), and three stocktypes (plug+1 bareroot, and 1+0 plugs from two nurseries) of white spruce (Picea glauca (Moench) Voss) were planted in freshly cutover areas on Fort Richardson, near Anchorage. Four vegetation-management treatments were compared: broadcast site preparation with herbicides, banded site preparation with herbicides, mechanical scarification, and untreated control. Spruce seedlings had the greatest growth in the broadcast site preparation treatment (p < 0.01). Stocktype was the most important factor in spruce growth, with bareroot transplant seedlings being the tallest and largest 5 years after planting (p < 0.001). In the first 3 years, relative stem volume growth was greater for plug seedlings than for bareroot seedlings (p < 0.001). By year 4, relative growth rates were similar among all stocktypes. Treatment effects for paper birch and willow were confounded by moose browsing. Results indicate spruce can be regenerated and moose browse enhanced simultaneously in forests in interior Alaska.


2019 ◽  
Vol 49 (5) ◽  
pp. 463-470 ◽  
Author(s):  
Suzanne Brais ◽  
Brian D. Harvey ◽  
Arun K. Bose

Variable retention (VR) and partial cutting are both considered important silvicultural tools of natural disturbance or ecosystem based forest management approaches. Partial harvesting differs from VR in that post-treatment growth responses and stand regeneration are the primary objective rather than the maintenance of biodiversity. This partial cutting study is undertaken in mixed poplar (Populus spp.) – white spruce (Picea glauca (Moench) Voss) stands in the eastern Canadian boreal mixedwood forest. It compares, at the tree level, absolute growth rates (AGR) and relative growth rates (RGR) of basal area (BA) and stem survival; and at the stand level, it also compares absolute BA growth, mortality, and sapling density 10 years following treatment. The completely randomized experiment was established with four intensities of partial cutting (0, 50%, 65%, and 100% of poplar BA). All partial cutting intensities had a significant and similar positive effect on AGR of residual spruce stems. Complete poplar removal resulted not only in the highest increase in RGR of suppressed and intermediate spruce stems, but also in higher spruce mortality. Removal of 50% of the initial poplar stand BA provided the best trade-off between positive residual stem growth of spruce and poplar and limited post-treatment mortality.


2001 ◽  
Vol 77 (6) ◽  
pp. 1006-1013 ◽  
Author(s):  
James D. Stewart ◽  
Simon M. Landhäusser ◽  
Kenneth J. Stadt ◽  
Victor J. Lieffers

Successful mixedwood management in the boreal forest of Alberta requires better knowledge of the occurrence and success of natural white spruce regeneration. In this study we developed statistical models to predict the natural establishment and height growth of understory white spruce (Picea glauca (Moench) Voss) in the boreal mixedwood forest in Alberta using data from 148 provincial permanent sample plots, supplemented by measurements of the amount and height growth of regenerating white spruce, and the amount and type of available substrate. A discriminant model correctly classified 73% of the sites as to presence or absence of a white spruce understory based on the amount of spruce basal area, rotten wood, ecological nutrient regime, soil clay fraction and elevation, although it explained only 30% of the variation in the data. On sites with a white spruce understory, a regression model related the abundance of regeneration to rotten wood cover, spruce basal area, pine basal area, soil clay fraction, and grass cover (R2 = 0.36). About half of the seedlings surveyed grew on rotten wood, and only 3% on mineral soil, and seedlings were 10 times more likely to have established on these substrates than on litter. Exposed mineral soil was rare, covering only 0.3% of the observed transect area, rotten wood covered 4.5%, and litter/undisturbed forest floor covered the remainder. The regression models developed for average relative height growth rate included feather moss cover, stand age and birch basal area for seedlings ≤ 1 m (R2 = 0.23), and feather moss cover, elevation, other moss cover and soil clay fraction for seedlings between 1 m and 3 m (R2 = 0.27). Key words: Picea glauca, seedling establishment, seedbeds, site factors, coarse woody debris, predictive models, mixedwood management


2011 ◽  
Vol 28 (2) ◽  
pp. 72-78 ◽  
Author(s):  
Anthony W. D'Amato ◽  
Stacy J. Troumbly ◽  
Michael R. Saunders ◽  
Klaus J. Puettmann ◽  
Michael A. Albers

Abstract The effects of thinning treatments on growth and survivorship of white spruce (Picea glauca [Moench] Voss) plantations affected by recent eastern spruce budworm (SBW) outbreaks were examined over a 5-year period in northern Minnesota. Thinning treatments increased individual tree growth, live crown ratios (LCRs), and survival relative to unthinned stands. Overall, stands affected by SBW had lower rates of volume production than unaffected stands. In addition, individual tree volume growth was greater in thinned SBW-affected stands relative to unthinned SBW-affected stands. Across stand conditions, individual tree postthinning volume growth response was best predicted by the interaction of prethinning LCR and postthinning relative density (RD). In particular, at low stocking levels (RD = 0.20) higher live crown values resulted in the highest volume growth ratios. On the other hand, at higher stocking levels (RD 0.40–0.55) volume growth was fairly consistent, regardless of LCRs. Across all stocking levels, a minimum LCR of 40% appears to ensure high tree and stand growth rates and is also an indicator of a tree's ability to respond positively to thinning. This plasticity of white spruce suggests that stands maintained at these crown target levels can achieve high levels of stand and individual tree productivity as long as appropriate LCRs are maintained.


2016 ◽  
Vol 46 (10) ◽  
pp. 1217-1223 ◽  
Author(s):  
Richard Kabzems ◽  
Philip G. Comeau ◽  
Cosmin N. Filipescu ◽  
Bruce Rogers ◽  
Amanda F. Linnell Nemec

Planting white spruce (Picea glauca (Moench) Voss) under established aspen (Populus tremuloides Michx.) stands has substantial potential for regenerating mixedwood ecosystems in the western Canadian boreal forest. The presence of an aspen overstory serves to ameliorate frost and winter injury problems and suppresses understory vegetation that may compete with white spruce. Under future climatic regimes with more frequent and severe drought episodes, underplanting may be a cost-effective strategy for lowering the risk of mortality in mixedwood regeneration. We examine the growth of white spruce during the first 18 years after being planted beneath a 39-year-old stand of trembling aspen. Treatments included thinning from over 6000 stems·ha−1 to 3000, 2000, and 1000 stems·ha−1 and fertilization. Initial stimulation of understory vegetation by fertilization had no measureable effect on spruce heights or diameters at year 18. Aspen thinning treatments did not have a significant effect on spruce height growth rates after spruce crowns had emerged above the understory shrub layer due to rapid aspen basal area increases after thinning. Small, but significant, increases for spruce height and diameter were present in the 1000 and 2000 stem·ha−1 aspen thinnings. A much wider range of aspen stand conditions may be suitable for planting spruce to create mixedwood ecosystems than has been previously considered.


2009 ◽  
Vol 85 (4) ◽  
pp. 631-638 ◽  
Author(s):  
Alison D Lennie ◽  
Simon M Landhäusser ◽  
Victor J Lieffers ◽  
Derek Sidders

Trembling aspen regeneration was studied in 2 types of partial harvest systems designed to harvest mature aspen but protect immature spruce and encourage natural aspen regeneration. Two partial harvest systems, where the residual aspen was either left in strips or was dispersed uniformly, were compared to traditional clearcuts. After the first and second year since harvest, aspen sucker density and growth was similar between the 2 partial harvests, but was much lower than in the clearcuts. However, in the partial cuts the regeneration density was very much dependent on the location relative to residual trees. The density of regeneration was inversely related to the basal area of residual aspen; however, sucker height was inversely related to the basal area of the residual spruce. Although there were adequate numbers of suckers after partial harvest, their viability and contribution to the long-term productivity of these mixedwood stands is not clear. Key words: silvicultural systems, forest management, residual canopy, white spruce, Populus tremuloides, Picea glauca, traffic


1998 ◽  
Vol 28 (12) ◽  
pp. 1794-1804 ◽  
Author(s):  
Richard C Yang

The aim of this study was to quantify the interactive response of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) to thinning and nitrogen (N) fertilization in midrotation stands by assessing foliar and stand growth response relationships and determining the optimum fertilizer regime. The experiment design was a factorial arrangement of treatments with two thinning intensities (thinned and unthinned control) and four N levels (0, 180, 360, and 540 kg·ha-1). Foliage was sampled annually from trees in buffers for 4 years following treatment and plot trees measured at a 5-year interval. Results indicated that the effect of fertilization on fascicle length and needle dry mass disappeared 2 years after N treatment, while thinning effects on foliage emerged 3 years after fertilization. Both first year fascicle length and dry mass were reliable predictors (r2 = 0.87 and 0.82, respectively) of subsequent stand volume growth. Applications of N at 360 kg·ha-1 to thinned and unthinned plots, respectively, improved 10-year periodic height increment by 20 and 19%, diameter at breast height by 29 and 34%, basal area by 21 and 36%, and total volume by 25 and 28%. Fertilization of N at this level appears to be optimal based on foliar and mensurational responses. High N loadings increased tree mortality and accelerated stand development and so it could be advantageously used as a tool for managing overstocked stands.


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