Comparaison de la croissance de marcottes d'épinette noire (Piceamariana) adultes après coupe à celle d'individus issus de graines après feu

1992 ◽  
Vol 22 (10) ◽  
pp. 1524-1535 ◽  
Author(s):  
Jean-Martin Lussier ◽  
Hubert Morin ◽  
Réjean Gagnon
Keyword(s):  
Specific Volume ◽  
Black Spruce ◽  
Volume Growth ◽  
Stem Analysis ◽  
Initial Height ◽  
Clear Cutting ◽  
Second Growth ◽  
Volume Increment ◽  
The Difference ◽  
The Moment

Analysis was performed on 112 stems of black spruce (Piceamariana (Mill.) BSP) from the Réserve faunique des Laurentides to compare the growth in height, DBH, and volume of layers released by clear-cutting to the growth of individuals of comparable age originating from seeds after fire. The sampled stands originated from fires and clear-cuttings that occurred between 1894 and 1941. Stem analysis also permitted the calculation of specific volume increment, which corresponds to the annual volume increment divided by the surface of the cambium. Results show that height, DBH, and volume measured 60 years after clear-cutting were better correlated to the height of the advanced growth at the moment of release (Ho) than to the number of years of suppression. The mean annual increments in height and DBH of released layers were positively related to height at the year of logging when the height was less than 2 m. When layers were taller, mean annual increments in height and DBH were negatively related to initial height. These relationships were however variable, since for two-thirds of the stand's life, the periodic annual increments in height and diameter did not differ significantly (α = 0.05) between small (Ho < 1 m ), medium (1 m ≤ Ho ≤ 2 m), and large second-growth spruces (Ho > 2 m). The superiority of taller layers is consequently due to greater heights before release. Volume growth rate of layers was positively related to initial height until approximately 60 years after clear-cutting. However, no differences in specific volume increment could be associated with initial height. Therefore, the relationship between initial height and volume increment can be attributed to the difference of cambial area between small, medium, and large second-growth spruces. Black spruce originating from seeds had greater height, DBH, and specific volume increments than second-growth trees, until about 50 years after stand origin. Thereafter, growth rates are comparable. Consequently, after 40 years, stands originating from seeds are comparable in height, volume, and DBH to layers that reached between 1 and 2 m in height after clear-cutting. Neither drainage class nor point density had a significant effect on the sampled black spruces. Stem analysis also revealed an important growth reduction that can be associated with the last spruce budworm (Choristoneurafumiferana Clem.) outbreak in the Réserve faunique des Laurentides. We can deduce from the results of this study that the performance of second-growth stands compared with fire-origin stands will mainly depend on the density of the advanced growth and its height structure.

Comparative growth and yield of layer- and seed-origin black spruce (Piceamariana) stands in Quebec

1992 ◽  
Vol 22 (4) ◽  
pp. 465-473 ◽  
Author(s):  
Hubert Morin ◽  
Réjean Gagnon
Keyword(s):  
Specific Volume ◽  
Black Spruce ◽  
Growth And Yield ◽  
Historical Records ◽  
Initial Height ◽  
Second Growth ◽  
Volume Increment ◽  
Seed Origin ◽  
The Mean ◽  
Fire Origin

Stem analysis was used to compare the height, diameter at breast height, and volume growth of seven merchantable black spruce (Piceamariana (Mill.) B.S.P.) stands regenerated after harvesting from advance growth of layer origin with the growth of three merchantable black spruce stands regenerated after fire from seed. The year of harvesting in the second-growth stands was precisely determined using synchronous growth release after logging, scars left by the logging operation, and historical records. The year of the fires in seed-origin stands was determined using fire scars and historical records. Fire-origin stands showed typical even-aged structure, and logged, second-growth stands showed an uneven-aged structure associated with an asymmetric curve. When compared with seed-origin stands, layer-origin stands showed a significantly greater total height 30 years after the stand origin because of the initial height of the layers. However, annual height increments were similar between the two origin types at 30 years. The mean diameter increment at 30 years was significantly higher in the second-growth stands. The mean annual specific volume increment values for the entire period of growth were slightly higher for the fire-origin stands. Layers that were small at the time of logging (<1 m) had a higher specific volume increment after logging compared with the medium (1–2 m) and tall layers (>2 m). There was a significant negative correlation between the height, diameter, and age of the layers at the time of logging and both the mean specific volume increment and the mean annual height increment 30 years after logging. In the second-growth stands, the number of merchantable trees and volume increment increased gradually because of the uneven structure of the stands. In contrast, in the seed-origin stands, the trees attained merchantable size at around 30 years after the fire, and the merchantable volume rose rapidly after this. The layer-origin populations had a significant advantage over the seed-origin populations because of the initial height and diameter of the layers at the time of logging. All seven layer-origin stands achieved, or were predicted to achieve, higher merchantable volumes than the seed-origin stands at 40 years. Our results indicate that the second-growth stands growing on mesic sites have the potential to produce merchantable forests comparable to the yield tables available for black spruce provided that the number of stems per hectare is adequate.

Vertical patterns in specific volume increment along stems of dominant jack pine (Pinus banksiana) and black spruce (Picea mariana) after thinning

2012 ◽  
Vol 42 (4) ◽  
pp. 733-748 ◽  
Author(s):  
Venceslas Goudiaby ◽  
Suzanne Brais ◽  
Frank Berninger ◽  
Robert Schneider
Keyword(s):  
Picea Mariana ◽  
Specific Volume ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Mass Density ◽  
Volume Growth ◽  
Jack Pine ◽  
Stem Volume ◽  
Volume Increment ◽  
Foliage Density

Jack pine ( Pinus banksiana Lamb.) and black spruce ( Picea mariana (Mill.) B.S.P.) total stem volume increment and vertical growth distribution after thinning were quantified and related to foliage biomass, foliage density, and growth efficiency (GE) (stem to foliage biomass ratio). Significant positive stem volume increments were observed following thinning for jack pine (3 years after) and black spruce (4 years after). Both species reacted differently in terms of the distribution in specific volume increments (SVI) (annual stem volume increment to cambial surface ratio): (i) for jack pine, an increase in SVI was first observed at the base of the tree, with the increase moving upwards, showing that the taper was likely to increase following thinning and (ii) for black spruce, the vertical distribution of SVI was constant, leading to no modifications in stem taper. For jack pine, total stem volume growth was related to an increase in GE and a greater foliage biomass at midcrown, with foliage density staying constant. For black spruce, however, no changes in GE, foliage biomass, and foliage mass density were observed.

Accroissement en volume de l'épinette noire: précision de sa détermination

1991 ◽  
Vol 21 (12) ◽  
pp. 1816-1822
Author(s):  
Richard Zarnovican
Keyword(s):  
Growth Rate ◽  
Prediction Model ◽  
Black Spruce ◽  
Volume Growth ◽  
Probability Level ◽  
Validation Data ◽  
Local Volume ◽  
Volume Increment ◽  
Annual Volume ◽  
Volume Equation

The relationship between volume growth rate and diameter growth rate (diameter at breast height) was studied from growth data established by stem analysis for dominant black spruce trees (Piceamariana (Mill.) B.S.P.) of a black spruce – feather moss stand. The results indicate a very close relationship between the two variables, and a linear model was chosen to predict volume growth rate. Independent model validation, based upon analysis of residual errors, indicates a small positive bias (0.006%) with a relatively good precision (±9.9%) and a χ2 test anticipated accuracy of ±0.71% at the 0.05 probability level. The annual volume increment calculated with the prediction model and with the local volume equation for validation data was more precise (bias = −0.02 dm3/year, precision = ±11.8%) than the volume increment calculated with this model and the general volume equation (bias = −0.39 dm3/year, precision = ±26.4%). Finally, the χ2 test showed that the anticipated accuracy of the annual volume increment was ±0.54 dm3/year at the 0.05 probability level for the prediction model and the local volume equation, and ±0.90 dm3/year for the prediction model and the general volume equation for validation data.

Croissance en hauteur à long terme de la régénération préétablie dans des pessières noires boréales régénérées par marcottage, au Québec

1992 ◽  
Vol 22 (4) ◽  
pp. 613-621 ◽  
Author(s):  
Raynald Paquin ◽  
René Doucet
Keyword(s):  
Growth Rate ◽  
Black Spruce ◽  
Height Growth ◽  
Growth Patterns ◽  
Dominant Position ◽  
Clear Cutting ◽  
Effective Age ◽  
Second Growth ◽  
Spruce Stands ◽  
To Come

Height-growth patterns of black spruce (Piceamariana (Mill.) B.S.P.) in the boreal forest were studied in layer-origin stands released by clear-cutting in the first half of this century. Most stems responded to release brought about by clear-cutting of the main stand. Initially, small stems responded more rapidly and more strongly, but their height-growth rate culminated between 20 and 30 years following release, the same period when height-growth rate culminated for the taller, older stems. After the culmination period, growth rates were independent of height at the time of release. Consequently, the taller stems at time of release were able to maintain their dominant position. Height growth over the recent years indicates that this position could be maintained in the years to come, and even indefinitely. It seems that second-growth black spruce stands behave like even-aged stands despite their uneven-aged structure. Consequently, years since release and stem height are more accurate measures of stem effective age than total age. Moreover, the taller stems in the understory, which are usually considerably older, should be considered to be as valuable as smaller regeneration when a stand is cut.

scholarly journals Ten-year Growth Response to Fertilizer of a 90-year-old Black Spruce Stand in Northwestern Ontario

1976 ◽  
Vol 52 (5) ◽  
pp. 233-236 ◽  
Author(s):  
I. K. Morrison ◽  
N. W. Foster ◽  
D. A. Winston ◽  
H. S. D. Swan
Keyword(s):  
Growth Response ◽  
Root Zone ◽  
Black Spruce ◽  
Volume Growth ◽  
Nutrient Loss ◽  
Growth Responses ◽  
Northwestern Ontario ◽  
Application Rates ◽  
Volume Increment ◽  
Range Test

A fertilizer experiment with three levels of urea, two of triple superphosphate and two of muriate of potash was established in a 90-year-old black spruce (Picea mariana [Mill.] B.S.P.) stand on a moist-to-wet site in northwestern Ontario. Response variables estimated or measured at 6 and 10 years after fertilization were mean DBH increment, BA increment (per cent and absolute), and total and merchantable volume increment. Analysis of variance and Duncan's New Multiple Range Test were carried out. Results indicated significant growth response only for one combination of N and P, and only in relation to mean DBH increment. No interactions were significant. Inspection of data revealed trends suggesting that response, which was limited, was generally to P and to a smaller degree to N. Compared with literature values, volume growth responses were generally low, about 9 m3/ha estimated total volume increment over controls in 10 years. Possible reasons for low response, including nutrient loss (particularly of N) from the root zone and low application rates are discussed.

The relation of balsam fir volume increment to cumulative spruce budworm defoliation

1996 ◽  
Vol 72 (5) ◽  
pp. 533-540 ◽  
Author(s):  
David A. MacLean ◽  
Eldon S. Eveleigh ◽  
Tony L. Hunt ◽  
Mervyn G. Morgan
Keyword(s):  
Specific Volume ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Regression Equations ◽  
Growth Reduction ◽  
Stem Analysis ◽  
Volume Increment ◽  
Mill Stand

The effect of cumulative defoliation caused by spruce budworm (Choristoneura fumiferana [Clem.]) from 1981 to 1987 on tree growth was assessed in a 35-year-old balsam fir (Abies balsamea [L.] Mill.) stand. After six years of moderate to severe defoliation, specific volume increment was reduced by an average of 11, 55, 83, 70, and 83% for trees with visual cumulative defoliation ratings, in 1987, of 1–25%, 26–50%, 51–75%, 76–90%, and 91–100%, respectively. Following defoliation, mean specific volume increment ranged from 0.02 cm3 cm−2 year−1 for trees with >90% cumulative defoliation to 0.16 cm3 cm−2 year for trees with <25% defoliation. Specific volume increment and percentage growth reduction were significantly related to the cumulative defoliation rating, with regression equations explaining 72 and 64%, respectively, of the variability among trees. It was concluded that onetime visual ratings of cumulative defoliation caused by spruce budworm can be used in assessing balsam fir growth rates and growth reduction. Key words: growth reduction, specific volume increment, stem analysis, Choristoneura fumiferana, Abies balsamea

scholarly journals Elastic Simulation of Joints with Particle-Based Fluid

2021 ◽  
Vol 11 (15) ◽  
pp. 6900
Author(s):  
Su-Kyung Sung ◽  
Sang-Won Han ◽  
Byeong-Seok Shin
Keyword(s):  
Principal Stress ◽  
Human Body ◽  
Yield Condition ◽  
Maximum Principal Stress ◽  
Human Motion ◽  
The Difference ◽  
The Moment ◽  
External Forces ◽  
Physical Changes ◽  
Elastic Simulation

Skinning, which is used in skeletal simulations to express the human body, has been weighted between bones to enable muscle-like motions. Weighting is not a form of calculating the pressure and density of muscle fibers in the human body. Therefore, it is not possible to express physical changes when external forces are applied. To express a similar behavior, an animator arbitrarily customizes the weight values. In this study, we apply the kernel and pressure-dependent density variations used in particle-based fluid simulations to skinning simulations. As a result, surface tension and elasticity between particles are applied to muscles, indicating realistic human motion. We also propose a tension yield condition that reflects Tresca’s yield condition, which can be easily approximated using the difference between the maximum and minimum values of the principal stress to simulate the tension limit of the muscle fiber. The density received by particles in the kernel is assumed to be the principal stress. The difference is calculated by approximating the moment of greatest force to the maximum principal stress and the moment of least force to the minimum principal stress. When the density of a particle increases beyond the yield condition, the object is no longer subjected to force. As a result, one can express realistic muscles.

scholarly journals Allometric Equations for Estimating Biomass and Carbon Stocks in Afforested Open Woodlands with Black Spruce and Jack Pine, in the Eastern Canadian Boreal Forest

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 59
Author(s):  
Olivier Fradette ◽  
Charles Marty ◽  
Pascal Tremblay ◽  
Daniel Lord ◽  
Jean-François Boucher
Keyword(s):  
Large Scale ◽  
Ad Hoc ◽  
Black Spruce ◽  
Tree Height ◽  
Jack Pine ◽  
Carbon Stocks ◽  
Allometric Equations ◽  
C Stocks ◽  
The Difference ◽  
Canadian Boreal Forest

Allometric equations use easily measurable biometric variables to determine the aboveground and belowground biomasses of trees. Equations produced for estimating the biomass within Canadian forests at a large scale have not yet been validated for eastern Canadian boreal open woodlands (OWs), where trees experience particular environmental conditions. In this study, we harvested 167 trees from seven boreal OWs in Quebec, Canada for biomass and allometric measurements. These data show that Canadian national equations accurately predict the whole aboveground biomass for both black spruce and jack pine trees, but underestimated branches biomass, possibly owing to a particular tree morphology in OWs relative to closed-canopy stands. We therefore developed ad hoc allometric equations based on three power models including diameter at breast height (DBH) alone or in combination with tree height (H) as allometric variables. Our results show that although the inclusion of H in the model yields better fits for most tree compartments in both species, the difference is minor and does not markedly affect biomass C stocks at the stand level. Using these newly developed equations, we found that carbon stocks in afforested OWs varied markedly among sites owing to differences in tree growth and species. Nine years after afforestation, jack pine plantations had accumulated about five times more carbon than black spruce plantations (0.14 vs. 0.80 t C·ha−1), highlighting the much larger potential of jack pine for OW afforestation projects in this environment.

Effects of Crown Thinning on Baldcypress Height, Diameter, and Volume Growth

1988 ◽  
Vol 12 (4) ◽  
pp. 252-256 ◽  
Author(s):  
Stephen G. Dicke ◽  
John R. Toliver
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Height Growth ◽  
Taxodium Distichum ◽  
Volume Increment ◽  
Crown Thinning ◽  
Epicormic Branching

Abstract Crown thinning a 63-year-old stand of baldcypress (Taxodium distichum [L.] Rich.) averaging 220 ft²/ac of basal area to 180, 140, and 100 ft²/ac resulted in 5-year diameter growths of 0.44, 0.51, and 0.77 in., respectively. The unthinned control was significantly less at 0.31 in. Six-year height growth averaged 3.1 ft and was not influenced by treatment. Thinning to 140 and 100 ft²/ac stimulated epicormic branching on many trees, which may lower log quality. All crown thinning treatments appeared to increase sawtimber volume increment and sawtimber volume/ac over the control 5 years after thinning. South. J. Appl. For. 12(4):252-256.

scholarly journals Loading Effect of Prosthetic Feet’s Anthropomorphicity on Transtibial Osseointegrated Implant

2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 681-687
Author(s):  
Mark Pitkin ◽  
Laurent Frossard
Keyword(s):  
Free Flow ◽  
Convex Shape ◽  
Bone Implant ◽  
Concave Shape ◽  
Early Loosening ◽  
Osseointegrated Implants ◽  
Osseointegrated Implant ◽  
Quantitative Characteristics ◽  
The Difference ◽  
The Moment

ABSTRACT Introduction Osseointegrated implants for direct skeletal attachment of transtibial prosthesis carry risks that are yet to be fully resolved, such as early loosening, mechanical failure of percutaneous and medullar parts of implant, periprosthetic issues, and infections. Underloading could lead to early loosening and infection. Overloading might compromise the bone–implant interface. Therefore, Goldilocks loading regimen applied by transtibial bone-anchored prostheses is critical for safe and efficient development of osseointegration around the implant during rehabilitation and beyond. We hypothesized that Goldilocks loading could be achieved when ambulating with a so-called anthropomorphic prosthetic ankle showing moment–angle relationship similar to a sound ankle. Materials and Methods Quantitative characteristics of the moment–angle curve of the sound ankle during dorsiflexion phase of a free-pace walking were extracted for 4 able-bodied participants (experiment 1). A slope of the moment–angle curve (stiffness) was calculated twice: for the first half and for the second half of the moment–angle curve. The difference of stiffnesses (those at the second half minus at the first half) was called the index of anthropomorphicity (IA). By definition, positive IA is associated with concave shape of the moment–angle curve, and the negative IA is associated with convex shape. In experiment 2, the same recordings and calculations were performed for 3 participants fitted with transtibial osseointegrated fixation during walking with their usual feet and the Free-Flow Foot (Ohio Willow Wood). The Free-Flow Foot was selected for its anthropomorphicity demonstrated in the previous studies with amputees using traditional socket attachment. Results The IA was 5.88 ± 0.93 for the able-bodied participants, indicating that the stiffness during the first part of the dorsiflexion phase was substantially fewer than during the second parts, as the calf muscles resisted to angulation in ankle substantially less than during the second part of dorsiflexion phase. For amputees fitted with Free-Flow Foot, IA was 2.68 ± 1.09 and −2.97 ± 2.37 for the same amputees fitted with their usual feet. Conclusions Indexes of anthropomorphicity, while of different magnitude, were positive in control able-bodied group and in the amputee group wearing Free-Flow Foot, which was qualitatively associated with concave shape of their moment–angle curves. The 3 usual feet worn by the participants were classified as nonanthropomorphic as their individual moment–angle curves were convex and the corresponding IAs were negative. Furthermore, this study showed that a foot with anthropomorphic characteristics tends to decrease maximal loads at the bone–implant interface as compared to the nonanthropomorphic feet and possibly may minimize the risks to compromise the integrity of this interface.

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