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.

Estimating Breast Height Diameters from Stump Measurements in British Columbia

1982 ◽  
Vol 58 (3) ◽  
pp. 143-145 ◽  
Author(s):  
Julien P. Demaerschalk ◽  
Stephen A. Y. Omule
Keyword(s):  
British Columbia ◽  
Prediction Model ◽  
Tree Species ◽  
Prediction System ◽  
Tree Diameter ◽  
Local Volume ◽  
Breast Height ◽  
Central Canada ◽  
Volume Equation ◽  
Stump Diameter

A means of estimating tree diameter at breast height from stump measurements has many applications. In this paper, metric equations are derived for estimating diameters at breast height from measured stump heights for all commercial tree species in British Columbia by age class and biogeoclimatic zones. The model found best was the same one as used by Alemdag and Honer (1977) for eleven tree species from eastern and central Canada. This prediction system can be incorporated into any local volume equation to derive a tree volume prediction model based on stump diameter and stump height.

scholarly journals Empowering Forest Owners with Simple Volume Equations for Poplar Plantations in the Órbigo River Basin (NW Spain)

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 124
Author(s):  
Roberto Blanco ◽  
Juan A. Blanco
Keyword(s):  
River Basin ◽  
Hybrid Poplar ◽  
Volume Growth ◽  
Forest Owners ◽  
Individual Tree ◽  
Average Growth ◽  
Volume Increment ◽  
Annual Volume ◽  
Poplar Plantations ◽  
Volume Equations

Hybrid poplar plantations are becoming increasingly important as a source of income for farmers in northwestern Spain, as rural depopulation and farmers aging prevent landowners from planting other labor-intensive crops. However, plantation owners, usually elderly and without formal forestry background, lack of simple tools to estimate the size and volume of their plantations by themselves. Therefore, farmers are usually forced to rely on the estimates made by the timber companies that are buying their trees. With the objective of providing a simple, but empowering, tool for these forest owners, simple equations based only on diameter were developed to estimate individual tree volume for the Órbigo River basin. To do so, height and diameter growth were measured for 10 years (2009–2019) in 404 trees growing in three poplar plantations in Leon province. An average growth per tree of 1.66 cm year−1 in diameter, 1.52 m year−1 in height, and 0.03 m3 year−1 in volume was estimated, which translated into annual volume increment of 13.02 m3 ha−1 year−1. However, annual volume increment was different among plots due to their fertility, with two plots reaching maximum volume growth around 11 years since planting and another at 13 years, encompassing the typical productivity range in plantations in this region. Such data allowed developing simple but representative linear, polynomial and power equations to estimate volume explaining 93%–98% of the observed variability. Such equations can be easily implemented in any cellphone with a calculator, allowing forest owners to accurately estimate their timber existences by using only a regular measuring tape to measure tree diameter. However, models for height were less successful, explaining only 75%–76% of observed variance. Our approach to generate simplified volume equations has shown to be viable for poplar, but it could be applied to any species for which several volume equations are available.

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.

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.

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.

Growth table for Corsican pine in Flanders (Belgium)

1991 ◽  
Vol 56 ◽  
Author(s):  
B. Meuleman
Keyword(s):  
Insect Pests ◽  
Sandy Loam ◽  
Stand Density ◽  
Forest Tree ◽  
Permanent Plots ◽  
New Findings ◽  
Volume Increment ◽  
The Mean ◽  
Annual Volume ◽  
Very High

After  its introduction at the start of this century, the Corsican pine has become  an important forest tree in Flanders (Belgium). The total area covered by  Corsican pine is about 11.000 ha. Due to climatological factors it is  virtually absent from the Walloon part of Belgium. Despite the crisis in 1984  - 1986, practical experiences with its vitality and disease resistance are  generally positive. Compared to Scots pine which is native to Belgium, its  productivity and insensitivity for insect pests is large.     To quantify the productivity of Corsican pine, a growth table was  constructed using a method developed by PALM and DAGNELIE. It was based on  data from 321 temporarily and 80 permanent plots distributed over Flanders.  Five yield classes were distinguished according to dominant height at 50  years. For each yield class, a series of tables as a function of treatment  was constructed. Treatments were characterized by the mean annual  circumference increment.     These tables allow to predict the growth of Corsican pines. Such  predictions for the whole range of species are necessary for the development  of a good forestry policy and for timber industries. The tables also provide  information for any given Corsican pine stand that is helpful in practice:  expected productivity, stand density, determination of the felling quantum.      The data show that the productivity of Corsican pine is very high. The very  early culmination of the current annual volume increment and the rather  constant level of the mean annual volume increment after culmination are  interesting new findings. It is also shown that it is possible to work with  long rotation periods. This offers good opportunities for the production of  high quality wood and is also important for the social and ecological role of  the forest.     Productivity is lowest on very dry and sandy soils. A high productivity on  moderately dry sand and loamy sand soils and loamy soils make the Corsican  pine one of the most valuable tree species for the Kempen in Flanders.  Although productivity is very high on well drained sandy loam and loam soils,  plantation of Corsican pine on these locations is not advised.

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 PROYEKSI STOKASTIK PRODUKSI PADI DI INDONESIA

2019 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Agnesya Dwitia ◽  
Agus Hudoyo ◽  
Adia Nugraha
Keyword(s):  
Growth Rate ◽  
Research Data ◽  
Rice Production ◽  
The Self ◽  
Staple Food ◽  
Probability Level ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Self Sufficiency ◽  
The Government

Rice is the staple food for Indonesian people and Indonesia was in self-sufficiency for rice in 1984. Based on the Agricultural Ministry’s Strategic Planning for 2015 – 2019, the government targeted that the self-sufficiency in rice in 2019 by 82,078 million tons of the rice production. It is better that the production is stochastically forecasted in form of the interval of projection possibility with the certain probability level. Therefore, the objective of this research is to know the growth of rice production and to stochastically forecast it. The data used in this research is the production of rice in the period of 1961 – 2015 obtained from the Food  and Agriculture Organization (FAO), and the Central Bureau of Statistics (CBS), Indonesia. The research data is analyzed by econometric method. The result revealed that the rice production would be 77,487 million tons in 2019 and it was 95% confidence interval would be between 74,901 and 80,071 million tons. The growth rate of the rice production in 2018 – 2020  would be 0.6 percent per year. We could conclude that the government target of the rice production was higher than the result of stochastic forecasting.Key words: forecast, paddy, production

Numerical Analysis of the Effect of Diffusion and Creep Flow on Cavity Growth

2007 ◽  
Author(s):  
Frederick W. Brust ◽  
Joonyoung Oh
Keyword(s):  
Growth Rate ◽  
Numerical Method ◽  
Cavity Growth ◽  
Volume Growth ◽  
Numerical Results ◽  
Shape Evolution ◽  
Cavity Volume ◽  
Cavity Shape ◽  
Cavity Growth Rate ◽  
Fully Coupled

In this paper, intergranular cavity growth in regimes, where both surface diffusion and deformation enhanced grain boundary diffusion are important, is studied. In order to continuously simulate the cavity shape evolution and cavity growth rate, a fully-coupled numerical method is proposed. Based on the fully-coupled numerical method, a gradual cavity shape change is predicted and this leads to an adverse effect on the cavity growth rates. As the portion of the cavity volume growth due to jacking and viscoplastic deformation in the total cavity volume growth increases, the initially spherical cavity evolves to V-shaped cavity. The numerical results are physically more realistic compared to results in the previous studies. The present numerical results suggest that the cavity shape evolution and cavity growth rate based on an assumed cavity shape, whether spherical or crack-like, cannot be used in this regime due to transitional coupled growth mechanisms.

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