AN ANALYSIS OF MEASURES OF DENSITY IN EVEN-AGED BALSAM FIR AND JACK PINE STANDS

1964 ◽  
Vol 40 (4) ◽  
pp. 474-481 ◽  
Author(s):  
P. E. Vezina
Keyword(s):  
Pinus Banksiana ◽  
Abies Balsamea ◽  
Basal Area ◽  
Stand Density ◽  
Jack Pine ◽  
Balsam Fir ◽  
Aerial Photographs ◽  
Growing Stock ◽  
The One ◽  
Crown Closure

The concept of stand density in relation to thinning is examined and its development over the years is discussed. Present difficulties of objectively measuring stand density are recognized and probable future trends towards the development of better formulae to express stand density are outlined. Researchers should continue to collect information on interrelationships among stand variables. Certain merits accrue from description of stand density in terms of variables, such as crown closure, that can be measured with some precision from aerial photographs. Conversely, valid estimates of crown closure which are often difficult to obtain by means of devices from the ground, could be predicted from stand density. Three stand variables, used as expressions of stand density, were tested in crown closure simple regressions in even-aged, unmanaged stands of balsam fir (Abies balsamea (L.) Mill.) and jack pine (Pinus banksiana Lamb.). These are: total number of trees, number of trees 4 inches and up, and basal area per acre. The strongest relationship found was the one where crown closure is compared with basal area; it was stronger for jack pine than for balsam fir. This was explained by differences in tolerance among the two species. The significance of these relationships for the stand development, and the feasibility of using height-and diameter-based indices as measures of growing stock in studies of yield are discussed.

Growth intercept models for black spruce, jack pine and balsam fir in Quebec

2005 ◽  
Vol 81 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Daniel Mailly ◽  
Mélanie Gaudreault
Keyword(s):  
Pinus Banksiana ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Site Index ◽  
Jack Pine ◽  
Balsam Fir ◽  
Practical Significance ◽  
Interim Testing ◽  
Growth Intercept ◽  
Mean Square Errors

The objective of this study was to develop variable growth intercept models for coniferous species of major importance in Quebec using Nigh's (1997a) modelling technique. Eighty-three, 68, and 70 stem analysis plots of black spruce (Picea mariana [Mill.] BSP), jack pine (Pinus banksiana Lamb.) and balsam fir (Abies balsamea (L.) Mill) were used, respectively. The growth intercept models for black spruce were the most precise, followed by those for jack pine and finally by those for balsam fir, based on the root mean square errors. Results indicated that the accuracy of the models was good, relative to those previously published for other species in Canada. Interim testing of the models revealed a low mean error for all three species that may not be of practical significance for site index determination, although more data should be obtained to further test the models. Key words: balsam fir, black spruce, growth intercept, jack pine, model, nonlinear regression, site index

Calibrating jack pine allometric relationships with simultaneous regressions

2008 ◽  
Vol 38 (10) ◽  
pp. 2566-2578 ◽  
Author(s):  
Robert Schneider ◽  
Frank Berninger ◽  
Chhun-Huor Ung ◽  
Pierre Y. Bernier ◽  
D. Edwin Swift ◽  
...  
Keyword(s):  
Pinus Banksiana ◽  
Basal Area ◽  
Stand Density ◽  
Jack Pine ◽  
Seemingly Unrelated Regression ◽  
Tree Level ◽  
Model Parameters ◽  
Eastern Canada ◽  
Sapwood Area ◽  
Pipe Model

Allometric equations for estimating foliage biomass, sapwood area, and branch basal area from tree diameters and crown lengths for jack pine ( Pinus banksiana Lamb.) in eastern Canada were calibrated using mixed models. A first model is presented that relates branch foliage biomass to branch diameter and relative position within the crown. These results show that a branch’s foliage biomass is inversely proportional to its depth within the crown. At the tree level, foliage biomass was found to be proportional to crown length and to vary with stem age and slenderness. Pipe model parameters (sapwood area and branch basal area to foliage biomass) were also calculated. The sapwood area to foliage biomass parameter is proportional to stand density, whereas branch basal area to foliage biomass is constant. The tree-level allometeric models were calibrated using a mixed-effects seemingly unrelated regression to account for between-model correlations.

Pines and porcupines: a tree-ring analysis of browsing and dynamics of an overmature pine forest

2017 ◽  
Vol 47 (2) ◽  
pp. 257-268 ◽  
Author(s):  
Amélie Rivet ◽  
Serge Payette ◽  
Dominique Berteaux ◽  
François Girard
Keyword(s):  
Tree Ring ◽  
Pinus Banksiana ◽  
Abies Balsamea ◽  
Abundant Species ◽  
Jack Pine ◽  
Balsam Fir ◽  
Late 20Th Century ◽  
The North ◽  
Feeding Activities ◽  
Ring Analysis

Past feeding activities of the North American porcupine (Erethizon dorsatum L.) in an overmature forest were reconstructed using tree-ring dated feeding scars on jack pine (Pinus banksiana Lamb.) trees in Parc national du Bic (Quebec). Following a long fire-free period, most pines that regenerated after the 1847 fire are currently senescent, moribund, or dead, and the youngest trees are nearly 100 years old. Balsam fir (Abies balsamea (L.) Mill.), the most abundant species in the regeneration layer, is predicted to replace jack pine given the absence of recent fire and present fire protection practices in the park. According to the age structure of feeding scars, porcupine activity has been particularly high during the 1980s, which is coincident with the creation of the park. Porcupine activity was lower before this decade and in the late 20th century and absent in this century (2000–2015). The recent decrease in the number of feeding scars is consistent with the decline of the porcupine population, as shown by censuses of active dens and inventories of individuals. Observed tree death is linked with tree senescence rather than excessive feeding. In the absence of fire, it is probable that the shift from the overmature pine stand to a balsam fir stand will profoundly affect porcupine activity. This research shows how the study of tree rings can unravel some of the ecological relationships structuring a forest ecosystem through fire, succession, and animal browsing.

scholarly journals Stand Density Management Diagram for Jack Pine Stands in Eastern Canada

2007 ◽  
Vol 24 (1) ◽  
pp. 22-29 ◽  
Author(s):  
Mahadev Sharma ◽  
S.Y. Zhang
Keyword(s):  
Pinus Banksiana ◽  
Stand Density ◽  
Jack Pine ◽  
Eastern Canada ◽  
Permanent Sample Plots ◽  
Quadratic Mean Diameter ◽  
Using Data ◽  
Stand Density Management ◽  
Crown Closure ◽  
Stand Density Management Diagram

Abstract A stand density management diagram was developed for jack pine (Pinus banksiana Lamb.) stands using the data obtained from 125 permanent sample plots (PSPs) established in Ontario and 232 PSPs in Quebec, Canada. The diagram was evaluated using data from 40 PSPs established in Ontario. Recently developed and efficient models have been used in constructing the diagram to estimate diameters and heights for the trees for which no diameters or heights were recorded at the time of stand inventory. Relative density indices of 0.15, 0.40, and 0.55 were used, corresponding to the line of approximate crown closure, the limit of productive zone, and the lower limit of competition-related mortality, respectively. If two stand characteristics are known, including mean total tree volume, quadratic mean diameter, trees per hectare, and average dominant height, the others can be readily obtained using the diagram. The consequences of various thinning scenarios can be plotted and visualized in the field without the need for computer simulation.

Basal area and diameter growth in high-graded eastern temperate mixedwood forests: the influence of acceptable growing stock, species, competition and climate

2019 ◽  
Vol 92 (5) ◽  
pp. 659-669 ◽  
Author(s):  
Hugues Power ◽  
Patricia Raymond ◽  
Marcel Prévost ◽  
Vincent Roy ◽  
Frank Berninger
Keyword(s):  
Abies Balsamea ◽  
Basal Area ◽  
Balsam Fir ◽  
Diameter Growth ◽  
Yellow Birch ◽  
Mixed Stands ◽  
Growing Stock ◽  
Mixedwood Forests ◽  
Stem Quality ◽  
History Of

AbstractHarvesting practices in temperate mixedwoods of eastern North America have a history of diameter-limit cuts, which have often resulted in degraded residual stands. In this study, we examined the factors influencing stand basal area (BA) and tree diameter growth in previously high-graded mixedwood forests, to understand which stands are more likely to recover from high-grading. Over 15 years, we monitored tree growth, recruitment and stem quality of 532 sample plots that were located in high-graded stands of Quebec’s mixedwood forest. We found that diameter growth rates were positively correlated with precipitation-related variables for balsam fir (Abies balsamea) and for yellow birch (Betulla alleghaniensis) but opposing trends for temperature-related variables were found. Conversely to balsam fir, yellow birch growth was positively correlated to temperature variables. Our results also show that BA growth was greater for plots with a larger acceptable growing stock (AGS: trees with potential sawlog production) and that the increase in AGS was greater for plots with larger amount of conifer BA. These result highlights the importance to maintain a proportion of conifer trees in these mixed stands. Moreover, the significant effect of asymmetric competition in our study underscores the relevance of considering the spatial distribution when choosing crop trees.

scholarly journals DERIVATION OF THINNING REGIMES THROUGH USE OF A MODEL FOR BALSAM FIR IN QUEBEC

1964 ◽  
Vol 40 (3) ◽  
pp. 362-371 ◽  
Author(s):  
P. E. Vezina
Keyword(s):  
Abies Balsamea ◽  
Basal Area ◽  
Balsam Fir ◽  
Growing Stock ◽  
Normal Number

A thinning regime was derived through use of a model developed to grow balsam fir (Abies balsamea (L.) Mill.) trees at any desired size between the limits set by normal and open stand densities. Interpolations were made between the normal number of trees in fully-stocked even-aged balsam fir stands and the number at which crowns of fully open-grown individual balsam fir just close at square spacing. The increase in the number of trees in a fully-stocked balsam fir stand of a given average d.b.h. being little influenced by site was used to establish the basis for the thinning regime. The simple regime prescribes a pre-commercial and two commercial thinnings, and a regeneration cutting when the stand reaches about 7 inches in d.b.h. From comparisons of the amount of growing stock of the hypothetical thinned stands with that of unmanaged fully-stocked stands, it would seem that a managed stand of balsam fir might carry a basal area per acre of 49, 58, and 75 per cent of the unmanaged stands at average d.b.h.'s of 3, 5 and 7 inches respectively.

scholarly journals Impact of a spruce budworm outbreak in balsam fir and subsequent stand development over a 40-year period

2008 ◽  
Vol 84 (1) ◽  
pp. 60-69 ◽  
Author(s):  
David A MacLean ◽  
Allison R Andersen
Keyword(s):  
Stand Structure ◽  
Abies Balsamea ◽  
Basal Area ◽  
Stand Density ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Stand Development ◽  
Wide Range ◽  
Break Up ◽  
The Impact

Nine 0.04-ha plots were established in 1956 (age 35 years) in a balsam fir (Abies balsamea [L.] Mill.) stand in northwestern New Brunswick, Canada to determine the impact of an uncontrolled spruce budworm (Choristoneura fumiferana [Clem.]) outbreak on stand development. The plots were measured annually from 1956 to 1961 and at five-year intervals from 1965 to 1995. Moderate to severe defoliation occurred from 1951 to 1957 and again in 1975 to 1977, 1981, and 1986 to 1988. Budworm-caused mortality from 1956 to 1961 (age 35 to 40 years) varied considerably among plots, reducing volume by 35 to 113 m3/ha (34%-84%), and resulting in a wide range of post-outbreak plot densities. Plots were grouped into three post-budworm outbreak (1965, age 45 years) basal area classes, of ≤ 20 m2/ha, 21 to 27 m2/ha, and ≥ 28 m2/ha, to examine stand recovery. Recovery of volume up to age 60 years ranged from 72 to 132 m3/ha, in the lowest to highest basal area classes, respectively. From age 60 to 75 years, five plots declined in volume due to the onset of stand break-up and four plots increased in volume. By age 60 years, survivor growth was greatest in the high basal area plots, ranging from 6.2 to 9.0 m3/ha/yr in seven plots, versus 2.6 to 3.2 m3/ha/yr in two low basal area plots. From age 60 to 75 years, survivor growth averaged only 2.8 to 5.2 m3/ha/yr, and the stand exhibited major decline, with 63%, 74%, and 78% mortality of fir ≤ 15 cm DBH in the low to high basal area plots, respectively. Budworm-caused "thinning" in the 1950s largely determined subsequent stand development and the rate of stand break-up 25 to 35 years later. The timing and rate of natural stand decline was strongly influenced by post-outbreak stand density. Key words: budworm-caused mortality, stand structure, stand development, growth, mortality, stand density

Modèles de croissance internodale pour l'épinette noire, le pin gris et le sapin baumier au Québec

2005 ◽  
Vol 81 (1) ◽  
pp. 114-124 ◽  
Author(s):  
Daniel Mailly ◽  
Mélanie Gaudreault
Keyword(s):  
Pinus Banksiana ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Site Index ◽  
Jack Pine ◽  
Balsam Fir ◽  
Practical Significance ◽  
Interim Testing ◽  
Growth Intercept ◽  
Mean Square Errors

The objective of this study was to develop variable growth intercept models for coniferous species of major importance in Quebec using Nigh's (1997a) modelling technique. Eighty-three, 68 and 70 stem analysis plots of black spruce (Picea mariana [Mill.] BSP), jack pine (Pinus banksiana Lamb.) and balsam fir (Abies balsamea (L.) Mill) were used, respectively. The growth intercept models for black spruce were the most precise, followed by those for jack pine and finally by those for balsam fir, based on the root mean square errors. Results indicated that the accuracy of the models was good, relative to those previously published for other species in Canada. Interim testing of the models revealed a low mean error for all three species that may not be of practical significance for site index determination, although more data should be obtained to further test the models. Key words: balsam fir, black spruce, growth intercept, jack pine, model, nonlinear regression, site index

scholarly journals Développement de sapinières éclaircies exposées à une épidémie de tordeuse des bourgeons de l'épinette

1998 ◽  
Vol 74 (1) ◽  
pp. 91-99 ◽  
Author(s):  
David Pothier
Keyword(s):  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Basal Area ◽  
Stand Density ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Growth And Yield ◽  
Annual Increment ◽  
Diameter Increment ◽  
Outbreak Period

In 1968, three intensities of low thinning were applied in 33-year-old balsam fir (Abies balsamea [L.] Mill.) stands of eastern Québec in order to remove 0, 20 and 30% of the total basal area. Sample plots were located in two distinct areas, one of which was annually sprayed with insecticides between 1978 and 1982 while the other was never protected against a spruce budworm (Choristoneura fumiferana [Clem.]) outbreak that occurred between 1976 and 1983. A total of 32 0.04-ha sample plots were periodically measured between 1968 and 1994. Low thinnings mostly removed non merchantable trees (DBH < 9.1 cm) and left 5 000 to 7 000 trees/ha while stand density of control plots reached 10 000 stems/ha. From 1968 to 1976, net annual increment in merchantable volume was around 8 m3/ha but no differences were detected between thinning levels. During the period of severe defoliation caused by spruce budworm (1976-1985), net annual increment in merchantable volume of sample plots sprayed with insecticides decreased by 50% but get back to its initial level after 1985. Net annual increment of sample plots that were never protected against spruce budworm was strongly negative during the outbreak period until the extinction of all trees was completed. While thinning level only slightly affected merchantable yield of sample plots during the 26-year period, mean annual increment in DBH was inversely proportional to stand density. This advantage of thinned plots could have been greater if stand density had been reduced further at the beginning of the study. Indeed, the analysis of the evolution of stand density as a function of mean volume of trees shows that mortality rate of all sample plots was similar to that given by the self-thinning rule. This suggests that even trees of most heavily thinned plots suffered from strong intra-specific competition. Key words: balsam fir, low thinning, spruce budworm, growth and yield, diameter increment, self-thinning rule

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