Tarifs de cubage paramétrés: application à l'épinette noire de Lebel-sur-Quévillon

1990 ◽  
Vol 20 (9) ◽  
pp. 1471-1478 ◽  
Author(s):  
Chhun-Huor Ung
Keyword(s):  
Black Spruce ◽  
Standing Stock ◽  
Analysis Data ◽  
Volume Estimation ◽  
Allometric Model ◽  
Stem Analysis ◽  
Forest Region ◽  
Spruce Stands ◽  
The Mean ◽  
The Cost

The mean ratio of height to diameter at breast height of dominant trees in a stand resulted in more accurate one-entry volume tables than general two-entry volume tables. These parametrical one-entry volume tables were established with the allometric model and Hummel's line. The values of their coefficients were estimated from stem analysis data of felled trees in black spruce stands at Lebel-sur-Quévillon. In the search for simple and effective methods to increase the reliability of standing stock estimation for managing a relatively homogeneous forest region, parametrical one-entry volume tables reduce the cost of estimating standing volume and increase the accuracy of volume estimation compared with general two-entry volume tables.

scholarly journals Comparative Height Growth of Eastern Larch and Black Spruce in Northwestern Ontario

1978 ◽  
Vol 54 (6) ◽  
pp. 296-297 ◽  
Author(s):  
Douglas A. Mead
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Height Growth ◽  
Larix Laricina ◽  
Stem Analysis ◽  
Northwestern Ontario ◽  
Analysis Methods ◽  
Spruce Stands

Height growth of eastern larch (Larix laricina (Du Roi) K. Koch) and black spruce (Picea mariana (Mill.) B.S.P.) was determined using standard stem analysis methods on trees from two sites in northwestern Ontario. The data were obtained from mixed larch-spruce stands which were relatively undisturbed. The larch exhibited substantially better height growth than the spruce through age 65.

Preliminary Site Index Equations for Three Planted Species in Northern Ontario

1995 ◽  
Vol 12 (2) ◽  
pp. 57-63 ◽  
Author(s):  
Bijan Payandeh ◽  
Yonghe Wang
Keyword(s):  
Nonlinear Analysis ◽  
Black Spruce ◽  
Analysis Data ◽  
Site Index ◽  
Analysis Of Covariance ◽  
Stem Analysis ◽  
Northern Ontario ◽  
Natural Stand ◽  
Graphical Comparison ◽  
Similarities And Differences

Abstract Stem analysis data from plantations of black spruce, white spruce, and jack pine from northern Ontario were fitted to base-age specific and base-age invariant site index models. The resulting equations and their respective parameters were compared via nonlinear analysis of covariance. The base-age specific models produced a somewhat better fit to the data than their base-age invariant counterparts, although the latter are considered theoretically more elegant. Graphical comparison of plantation and natural stand site index curves for the three species showed both similarities and differences. North. J. Appl. For. 12(2):57-63.

Soil oxygen within boreal forests across an age gradient

2006 ◽  
Vol 86 (1) ◽  
pp. 1-9 ◽  
Author(s):  
N. Fenton ◽  
S. Légaré ◽  
Y. Bergeron ◽  
D. Paré
Keyword(s):  
Water Table ◽  
Boreal Forests ◽  
Forest Floor ◽  
Black Spruce ◽  
Methodological Issue ◽  
Mineral Soil ◽  
Forest Region ◽  
Feather Mosses ◽  
Spruce Stands ◽  
Potential Factors

Globally, soil anoxia and water table rise play a role in the development of peatlands from forests. Cited causes have included a diversity of internal and external mechanisms, including Sphagnum and feather mosses, hardpan development, and peatland expansion. The objectives of this study were to examine water table depth in black spruce stands of the Clay Belt of Quebec and Ontario, and to associate changes with potential stand scale causal factors (primarily biological). A methodological issue, the link between oxygen zone and water table, was also addressed. Within stands less than 100 yr post-fire, oxygen zone and water table position were only loosely related, and no other potential factors were significantly correlated. Across a chronosequence of stands, while oxygen zone thickness in the soil profile was relatively constant, its position relative to the mineral soil changed, as it rose from the mineral soil into the forest floor. Forest floor thickness was the dominant explanatory factor in oxygen zone position, suggesting that in these forests other postulated mechanisms are less important. At the landscape level, the movement of the oxygen zone into the forest floor has important consequences for the long-term productivity of this intensively exploited forest region. Key words: Water table, black spruce, paludification, forest floor, Clay Belt, Sphagnum

scholarly journals Evaluating Height‐Age Determination Methods for Jack Pine and Black Spruce Plantations Using Stem Analysis Data

2010 ◽  
Vol 27 (2) ◽  
pp. 50-55 ◽  
Author(s):  
Nirmal Subedi ◽  
Mahadev Sharma
Keyword(s):  
Picea Mariana ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Age Determination ◽  
Analysis Data ◽  
Jack Pine ◽  
Stem Analysis ◽  
Prediction Bias ◽  
Height Prediction ◽  
Determination Methods

Abstract Six height‐age determination methods (Graves, Lenhart, Carmean, Newberry, ratio, and ISSA) were evaluated for their accuracy and sensitivity to sample size in determining height‐age pairs using stem analysis data from plantation-grown black spruce (Picea mariana[Mill.] B.S.P.) and jack pine (Pinus banksiana Lamb.) trees from Ontario, Canada. Twenty-three disks (sections) were used from 102 jack pine and 93 black spruce trees each for evaluation. The Graves, ratio, and Newberry methods were unbiased for determining height‐age pairs forboth black spruce and jack pine across the site productivity gradient and different crown classes. However, on the basis of the magnitude of height prediction bias, reconstructed tree profiles, and the amount of information required for height‐age determination, the Graves method withat least 13 stem sections is recommended for height‐age determination.

Asymptotic Site-Index Curves, Fact or Artifact?

1984 ◽  
Vol 60 (3) ◽  
pp. 150-156 ◽  
Author(s):  
Victor G. Smith
Keyword(s):  
Black Spruce ◽  
Analysis Data ◽  
Site Index ◽  
Sample Plot ◽  
Stem Analysis ◽  
Permanent Sample Plots ◽  
Variable Site ◽  
Permanent Sample Plot ◽  
Regression Techniques ◽  
Curve Method

In the absence of permanent sample plot data, site-index curves and equations showing the height/age relationship for a tree species growing on a given site have been derived using stem analysis and temporary sample plot data. Initially the guide-curve method using temporary sample plot data (Bruce and Schumacher 1950) was employed to produce anamorphic site-index curves. More recently mensurationists (e.g. Heger 1968, and Payandeh 1978) have used stem analysis data and various regression techniques to produce polymorphic curves. This study suggests that the asymptotic site-index curves (i.e. curves that tend to level off within the life of the stand) that have been produced for black spruce may be the result of using mensurational and sampling techniques in forests where site-index is correlated with age. Also the regression techniques commonly used to estimate the parameters in site-index equations do not allow for error in both the dependent variable (height) and an independent variable (site). As a consequence the site-index curves produced by these techniques are asymptotic whereas height estimates obtained from 40 black spruce permanent sample plots do not exhibit any strong asymptotic height properties for stands up to 180 years of age.

Développement d’un outil de classification de la structure des peuplements et comparaison de deux territoires de la pessière à mousses du Québec

2003 ◽  
Vol 79 (2) ◽  
pp. 318-328 ◽  
Author(s):  
D Boucher ◽  
L De Grandpré ◽  
S Gauthier
Keyword(s):  
Forest Management ◽  
Boreal Forest ◽  
Stand Structure ◽  
Black Spruce ◽  
Structural Diversity ◽  
Spruce Forest ◽  
Forest Stands ◽  
Statistical Tool ◽  
Forest Region ◽  
Spruce Stands

Forest stand structure is an important element for biodiversity and, from a sustainable forest management perspective, uneven-sized stands should be managed in order to maintain the structural diversity over the landscape. The first objective of this study is to develop a statistical tool to characterize stand structure that can be used in forest management planning. The second objective is to classify the stand structure of two regions to illustrate a possible use for the tool. The statistical tool for characterizing stand structure has been developed from forest inventory data gathered by the ministère des Ressources naturelles du Québec, using discriminant analysis. The analysis makes it possible to classify the stands into three types of structure, even-sized, uneven-sized and inverse J-shaped, with an error rate estimated at only 7%. Proportions of different structure types in Quebec’s eastern black spruce forest region have been compared with those found in the western black spruce forest region. Nearly 90% of the western black spruce forest region is composed of pure black spruce stands, contrary to the eastern black spruce region, where there are more pure fir and mixed spruce-fir stands. Most of the western black spruce forest stands are even-sized (62%), while almost 70% of the eastern black spruce forest stands are uneven-sized or inverse J-shaped. Pure black spruce stands are more even-sized than pure fir stands, but regional differences are also found within pure black spruce stands. Our results show that it is possible to develop a robust tool that makes it possible to classify thousands of stands rapidly. Such tools are required if we want to consider stand structure for appropriate management prescriptions in the boreal forest. Key words: Even- and uneven-sized structure, fire regime, Picea mariana, Abies balsamea, boreal forest, structural diversity

Structure et croissance de peuplements d'épinette noire issus de régénération préétablie, une quarantaine d'années après coupe au Lac Saint-Jean, Québec

1991 ◽  
Vol 67 (3) ◽  
pp. 275-283 ◽  
Author(s):  
Hubert Morin ◽  
Réjean Gagnon
Keyword(s):  
Black Spruce ◽  
Height Growth ◽  
Diameter Distribution ◽  
Drainage Pattern ◽  
Stem Analysis ◽  
Wood Processing ◽  
Spruce Stands ◽  
Negative Exponential ◽  
Mature Stands ◽  
Diameter Classes

Age, height and diameter distribution as well as height and diameter growth were studied in ten mesic black spruce stands originating from advance growth, forty years after cutting. All sampled stands showed a negative exponential type age structure. The majority of the trees were of layer origin established in the mature stands that were cut in the 1930's or 1940's. The sampled trees were generally distributed among numerous height and diameter classes. According to stem analysis, the ten sampled stands can be separated into two distinct groups based on their height growth performance, following the drainage pattern. Mean annual height and diameter increments were comparable to those described in yield tables for natural black spruce stands. Sites with adequate stocking and density should thus give good volumes. Stands of advance growth origin have the advantage of possessing some trees with a certain height immediately after the cutting. However, they are generally highly variable in diameter and height classes which can be an inconvenience in wood processing

Design and development of manually operated gladiolus planter

2018 ◽  
Vol 5 (01) ◽  
Author(s):  
TAPAN K. KHURA ◽  
H. L. KUSHWAHA ◽  
SATISH D LANDE ◽  
PKSAHOO . ◽  
INDRA L . KUSHWAHA
Keyword(s):  
Coefficient Of Variation ◽  
Field Capacity ◽  
Power Source ◽  
Forward Speed ◽  
Cereal Crop ◽  
Maximum Coefficient ◽  
Coefficient Of Uniformity ◽  
The Mean ◽  
The Cost ◽  
Immense Potential

Floriculture is an age-old farming activity in India having immense potential for generating selfemployment and income to farmers. However, the cost of cultivation of flower is high as compared to cereal crop. Level of mechanization for different field operations is one but foremost reason for the higher cost of cultivation. As most of the Indian farmers are marginal and small, a need for manually operated gladiolus planter was felt. The geometric properties of gladiolus corm were determined for designing the seed metering system and seed hopper of the planter. The planter was evaluated in the field when pulled by two persons as a power source and guided by a person. The coefficient of variation and highest deviation from the mean spacing was observed as 12.93% and 2.65cm respectively. The maximum coefficient of uniformity of 90.59% was observed for a nominal corm spacing of 15cm at 0.56 kmh-1 forward speed. An average MISS percentage was observed as 2.65 and 2.25 for nominal corm spacing of 15 and 20 cm. The multiple index was zero for two levels corm spacing and forward speed of operation. The QFI was found in the range of 97.2 and 97.9 percent. The average field capacity of the planter was observed as 0.02 hah-1.The average draft requirement of the planter was found as 821 ± 50.3 N.

scholarly journals Economic Value of Terminal Aerodrome Forecasts at Incheon Airport, South Korea

2021 ◽  
Vol 13 (12) ◽  
pp. 6965
Author(s):  
In-Gyum Kim ◽  
Hye-Min Kim ◽  
Dae-Geun Lee ◽  
Byunghwan Lim ◽  
Hee-Choon Lee
Keyword(s):  
Decision Making ◽  
South Korea ◽  
Co2 Emissions ◽  
Fuel Efficiency ◽  
Economic Value ◽  
Analysis Data ◽  
Annual Average ◽  
Loss Model ◽  
Total Budget ◽  
The Cost

Meteorological information at an arrival airport is one of the primary variables used to determine refueling of discretionary fuel. This study evaluated the economic value of terminal aerodrome forecasts (TAF), which has not been previously quantitatively analyzed in Korea. The analysis data included 374,716 international flights that arrived at Incheon airport during 2017–2019. A cost–loss model was used for the analysis, which is a methodology to evaluate forecast value by considering the cost and loss that users can expect, considering the decision-making result based on forecast utilization. The value was divided in terms of improving fuel efficiency and reducing CO2 emissions. The results of the analysis indicate that the annual average TAF value for Incheon Airport was approximately 2.2 M–20.1 M USD under two hypothetical rules of refueling of discretionary fuel. This value is up to 26.2% higher than the total budget of 16.3 M USD set for the production of aviation meteorological forecasts by the Korea Meteorological Administration (KMA). Further, it is up to 10 times greater than the 2 M USD spent on aviation meteorological information fees collected by the KMA in 2018.

scholarly journals Seasonal Influenza and Low Flu Vaccination Coverage as Important Factors Modifying the Costs and Availability of Hospital Services in Poland: A Retrospective Comparative Study

2021 ◽  
Vol 18 (10) ◽  
pp. 5173
Author(s):  
Robert Susło ◽  
Piotr Pobrotyn ◽  
Lidia Brydak ◽  
Łukasz Rypicz ◽  
Urszula Grata-Borkowska ◽  
...  
Keyword(s):  
Influenza Season ◽  
Influenza Infection ◽  
Hospital Staff ◽  
University Hospital ◽  
Control Group ◽  
Admission Rates ◽  
Risk Of Death ◽  
The Mean ◽  
Retrospective Comparative Study ◽  
The Cost

Introduction: Influenza infection is associated with potential serious complications, increased hospitalization rates, and a higher risk of death. Materials and Methods: A retrospective comparative analysis of selected indicators of hospitalization from the University Hospital in Wroclaw, Poland, was carried out on patients with confirmed influenza infection in comparison to a control group randomly selected from among all other patients hospitalized on the respective wards during the 2018–2019 influenza season. Results: The mean laboratory testing costs for the entire hospital were 3.74-fold higher and the mean imaging test costs were 4.02-fold higher for patients with confirmed influenza than for the control group; the hospital expenses were additionally raised by the cost of antiviral therapy, which is striking when compared against the cost of a single flu vaccine. During the 2018–2019 influenza season, influenza infections among the hospital patients temporarily limited the healthcare service availability in the institution, which resulted in reduced admission rates to the departments related to internal medicine; the mean absence among the hospital staff totaled approximately 7 h per employee, despite 7.3% of the staff having been vaccinated against influenza at the hospital’s expense. Conclusions: There were significant differences in the hospitalization indicators between the patients with confirmed influenza and the control group, which markedly increased the hospital care costs in this multi-specialty university hospital.

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