Adjustment of the age–height relationship for uneven-aged black spruce stands

2008 ◽  
Vol 38 (7) ◽  
pp. 2003-2012 ◽  
Author(s):  
Hakim Ouzennou ◽  
David Pothier ◽  
Frédéric Raulier
Keyword(s):  
Black Spruce ◽  
Information Criterion ◽  
Diversity Indices ◽  
Site Index ◽  
Diameter Distribution ◽  
Large Network ◽  
Permanent Sample Plots ◽  
Dominant Height ◽  
Spruce Stands ◽  
Height Model

Site index (SI) is commonly used in natural stands, even when their diameter distribution deviates from that of the monospecific, even-aged, fully stocked stands used to develop basic age–height relationships. Since deviations from basic age–height trajectories can be reflected in deviations of stand diameter distribution from a bell shape, we incorporated different diameter diversity indices into an age–height equation to help improve height predictions and determine which index is best related to stand dominant height. This procedure was performed using black spruce ( Picea mariana (Mill.) BSP) stands from a large network of permanent sample plots established across the province of Quebec, Canada. The age–height model that minimized the Akaike’s information criterion used the Shannon evenness index (ESh) as an equation modifier accounting for the diameter diversity variable. The model showed that for stands established on relatively poor sites (SI = 9), no substantial differences in dominant height were found between two contrasting ESh values. For SI = 15, however, the larger ESh value increased the dominant height by as much as 1 m at 80 years. These results suggest that introduction of ESh into an age–height model can improve calculation of site index, particularly in regions characterized by the presence of numerous uneven-aged stands.

scholarly journals Base–age Invariant Polymorphic Height Growth and Site Index Equations for Peatland Black Spruce Stands

2008 ◽  
Vol 25 (4) ◽  
pp. 202-210 ◽  
Author(s):  
Peter F. Newton
Keyword(s):  
Black Spruce ◽  
Site Index ◽  
Height Growth ◽  
Growth Patterns ◽  
Growth Equation ◽  
Data Set ◽  
Error Type ◽  
Dominant Height ◽  
Spruce Stands ◽  
New Equation

Abstract The goal of this study was to develop base–age invariant polymorphic height growth and site index equations for peatland black spruce (Picea mariana [Mill.]; BSP) stands situated within the western portion of the Northern Clay section of the Canadian Boreal Forest region. Procedurally, equation parameters were estimated via ordinary least squares analysis using 291 mean dominant height − mean stand age (Hd − As) data pairs derived from 42 permanent sample plots (PSPs). The predictive ability of the resultant height growth equation was evaluated by examining mean absolute and relative errors and associated 95% prediction intervals over 5-, 15-, 25-, 35-, and 45-year projection periods. Furthermore, using an independent data set consisting of 129 Hd − As data pairs derived from 24 PSP, the new height growth equation was compared with two preexisting equations. Overall, the results indicated that the predictions derived from the new equation were unbiased irrespective of error type or projection period length and that the new equation exhibited greater predictive accuracy and was more consistent with expected dominant height development patterns than the preexisting equations. Consequently, the new equations are recommended for use when describing height growth patterns or quantifying site quality within peatland black spruce stands.

scholarly journals Juvenile Height Development in Interior Spruce Stands of British Columbia

2000 ◽  
Vol 15 (3) ◽  
pp. 117-121 ◽  
Author(s):  
Gordon D. Nigh ◽  
Bobby A. Love
Keyword(s):  
Decision Making ◽  
British Columbia ◽  
Site Index ◽  
Timber Supply ◽  
Breast Height ◽  
Forest Region ◽  
Interior Spruce ◽  
Spruce Stands ◽  
Age Model ◽  
Height Model

Abstract Good estimates of juvenile heights are important for silviculture and timber supply decision-making. These height estimates are particularly important for estimating the number of years it takes a stand to reach green-up and breast height. Thirty-nine 0.04 ha plots were established in managed juvenile stands of interior spruce in the Prince Rupert Forest Region. Four sample trees in each plot were split longitudinally and height-age data were obtained from the exposed pith nodes or branch whorls. The height-age data were fit to a combined exponential and power function to create a juvenile height model for interior spruce. This model is a function of age and site index. Years to breast height and green-up age models were developed with data generated from the juvenile height model. Forecasts from these models indicate that the time to reach breast height and green-up age is less than previously expected. The juvenile height model, years to breast height model, and green-up age model should be used for site indices above 14.2 m. In addition, the height model should only be used up to total age 20. West. J. Appl. For. 15(3):117-121.

scholarly journals EVOLUÇÃO DA ÁREA BASAL E DO VOLUME EM BRACATINGAIS NATIVOS SUBMETIDOS À DIFERENTES DENSIDADES INICIAIS E EM DIFERENTES SÍTIOS

FLORESTA ◽  
2002 ◽  
Vol 32 (1) ◽  
Author(s):  
Sebastião Do Amaral Machado ◽  
Ana Elizabete N. Tonon ◽  
Afonso Figueiredo Filho ◽  
Edilson Batista Oliveira
Keyword(s):  
Initial Density ◽  
Basal Area ◽  
Site Index ◽  
Metropolitan Region ◽  
Data Set ◽  
Permanent Sample Plots ◽  
Dominant Height ◽  
Site Classes ◽  
Volume Em ◽  
Area And Volume

Foram analisados os efeitos de quatro densidades iniciais (2, 4, 8 e 25,15 mil plantas por hectare) e de 3 classes de sítio, cujos índices de sítios são 10,2; 13,5 e 16,8 m de altura dominante aos 7 anos de idade, sobre a área basal e volume por hectare em povoamentos nativos de bracatinga (Mimosa scabrella Benth.) na região metropolitana de Curitiba. Os dados provieram de um experimento de densidades em blocos ao acaso medidos nas idades de 4,1; 5,1; 6,3 e 7,6 anos. Os efeitos da densidade inicial e do sítio sobre a área basal (G) e volume (V) por hectare foram verificados através de análise de variância seguida do teste de Tukey, quando pertinente. A densidade inicial de 4 mil plantas por hectare gerou maiores valores de G e V nas últimas idades de medição. A área basal/ha não sofreu efeitos significativos do sítio em nenhuma das medições, enquanto que o volume/ha foi afetado por este fator (sítio) até a idade de 6,3 anos. Evolution of Basal Area and Volume per Hectare in Native "Bracatingais" Submited to Different Initial Densities and Different Sites Abstract The objectives of this research were to study the effects of four initial densities (2000, 4000, 8000 and 25150 plants/ha) and three site classes (site index 10.2, 13.5 and 16.8 m of dominant height at age seven) on basal area (G) and volume per hectare (V) for native stands of bracatinga (Mimosa scabrella Benth.) in the Metropolitan Region of Curitiba, Brazil. The data set came from permanent sample plots of a density trial established in a random blocks design. These plots were measured at ages 4.1, 5.1, 6.3, and 7.6 years of age. The effects of initial density and site on basal area and volume per hectare were verified through graphics and analysis of variance followed by the Tukey test when necessary. The initial density of 4,000 plants/ha generated the highest values of basal area and volume in the last ages of measurement. The basal area/ha did not sufered significative effects of site at any one of the measurement ages, while volume/ha was affected by this factor (site) until the age of 6.3 years.

scholarly journals Dominant Height Model for Site Classification ofEucalyptus grandisIncorporating Climatic Variables

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
José Roberto Soares Scolforo ◽  
Romualdo Maestri ◽  
Antonio Carlos Ferraz Filho ◽  
José Márcio de Mello ◽  
Antônio Donizette de Oliveira ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Eucalyptus Grandis ◽  
Site Index ◽  
Climatic Variables ◽  
Site Classification ◽  
Monthly Precipitation ◽  
Annual Increment ◽  
Dominant Height ◽  
Mean Annual Increment ◽  
Height Model

This study tested the effects of inserting climatic variables inEucalyptus grandisas covariables of a dominant height model, which for site index classification is usually related to age alone. Dominant height values ranging from 1 to 12 years of age located in the Southeast region of Brazil were used, as well as data from 19 automatic meteorological stations from the area. The Chapman-Richards model was chosen to represent dominant height as a function of age. To include the environmental variables a modifier was included in the asymptote of the model. The asymptote was chosen since this parameter is responsible for the maximum value which the dominant height can reach. Of the four environmental variables most responsible for database variation, the two with the highest correlation to the mean annual increment in dominant height (mean monthly precipitation and temperature) were selected to compose the asymptote modifier. Model validation showed a gain in precision of 33% (reduction of the standard error of estimate) when climatic variables were inserted in the model. Possible applications of the method include the estimation of site capacity in regions lacking any planting history, as well as updating forest inventory data based on past climate regimes.

An assessment of the structural method of deriving a black spruce site equation

1987 ◽  
Vol 17 (10) ◽  
pp. 1181-1189 ◽  
Author(s):  
Victor G. Smith ◽  
Martin Watts
Keyword(s):  
Black Spruce ◽  
Nonlinear Models ◽  
Site Index ◽  
Stand Age ◽  
Structural Method ◽  
Northern Ontario ◽  
Data Set ◽  
Permanent Sample Plots ◽  
Stochastic Error ◽  
Stand Height

To date, methods of deriving site index (S) equations assume that stochastic error is only present in the regressor. This paper develops a method, termed the "structural method," which recognizes that both dominant stand height (H) and S measurements contain stochastic error. To achieve this, the structural method utilizes the structural relationship that exists between H and S to derive an S equation. S equations are derived for black spruce, Piceamariana (Mill.) B.S.P., using the structural method and various other methods, with linear and nonlinear models that are currently in use. Data used in the study consist of 56 black spruce permanent sample plots, containing a total of 382 observations, from north central Ontario and the Clay Belt Region of northern Ontario. This data set is split into 36 plots (260 observations) for deriving S equations and 20 plots (122 observations) for testing the equations for accuracy in predicting H, S, and future H. The equations are also examined for bias over stand age. Results show that height development of black spruce is not asymptotic and is best described by a linear model. Overall, the structural method provides the most accurate S equation within the range of the data. It predicted 90% of the H test observations with an error of 0.4 m or less, 89% of the S test observations with an error of 0.4 m or less, and 90% of the future H test observations with an error of 0.7 m or less. The structural method also has the advantage of producing only one equation for predicting both H and S. This enables estimates of both H and S to be made from one graph of H over age by S classes.

An index of site productivity for uneven-aged or mixed-species stands

1993 ◽  
Vol 23 (3) ◽  
pp. 558-562 ◽  
Author(s):  
Shongming Huang ◽  
Stephen J. Titus
Keyword(s):  
Black Spruce ◽  
Tree Height ◽  
Site Index ◽  
Weibull Function ◽  
Growth Data ◽  
Site Productivity ◽  
Mixed Species ◽  
Quick Method ◽  
Permanent Sample Plots ◽  
Productivity Measure

A site productivity measure based on the relationship between total tree height and diameter at breast height of dominant and codominant trees was presented for four major tree species (white spruce (Piceaglauca (Moench) Voss), lodgepole pine (Pinuscontorta Dougl.), trembling aspen (Populustremuloides Michx.), and black spruce (Piceamariana (Mill.) B.S.P.)) growing in boreal mixed-species stands in Alberta. The measure is based on a three-parameter modified Weibull function fitted to growth data from permanent sample plots using the difference-equation method; R2-values ranged from 0.90 to 0.97. The measure has many logical properties similar to those of the site-index approach and produces curves that are polymorphic and reference-diameter invariant. It can be used as a simple and quick method of quantifying site productivity for uneven-aged and (or) mixed-species stands.

Stand volume tables: Application to black spruce stands of Lebel-sur-Quévillon

1991 ◽  
Vol 67 (6) ◽  
pp. 712-715 ◽  
Author(s):  
Chhun-Huor Ung ◽  
Denis Ouellet
Keyword(s):  
Large Scale ◽  
Black Spruce ◽  
Form Factors ◽  
Basal Area ◽  
Great Stability ◽  
Stand Volume ◽  
Volume Table ◽  
Dominant Height ◽  
Substantial Error ◽  
Spruce Stands

Within the framework of large-scale forest management, the application of Eichhorn's law, which employs dominant height or mean height exclusively to predict tree volumes per hectare, is certainly rapid, but high accuracy is not guaranteed. Substantial error occurred when this method was used in a study of boreal black spruce stands (Picea mariana (Mill.) B.S.P.). Use of both basal area per hectare and dominant height, however, permitted estimation of total volume per hectare and volume to 9 cm top with only 11 and 12% error, respectively. The form factors for total volume and volume to 9 cm top showed great stability. For this reason, use of the simple conventional formula (V = G.H.F.) to estimate standing volumes is justified. Key words: Stand volume table, Eichhorn's law, stand form factor

The effect of advance regeneration height on future yield of black spruce stands

1995 ◽  
Vol 25 (4) ◽  
pp. 536-544 ◽  
Author(s):  
David Pothier ◽  
René Doucet ◽  
Jocelyn Boily
Keyword(s):  
Black Spruce ◽  
Site Index ◽  
Site Quality ◽  
Management Tools ◽  
Clear Cutting ◽  
Advance Regeneration ◽  
Short Period ◽  
Index Site ◽  
Spruce Stands ◽  
Stand Height

The advance regeneration often present following clear-cutting in black spruce (Piceamariana (Mill.) B.S.P.) stands is generally composed of individuals of various heights. This initial height difference is hypothesized to affect the yield of the future stand. Height of the advance regeneration at time of release was determined on several black spruce trees within 33 stands distributed across the boreal forest of the province of Quebec, Canada. From these data, a regeneration structure index was developed and used to explain a part of the variation in subsequent stand yield. Dominant trees of stands developing for 38 to 65 years since clear-cutting generally originated from the tallest advance regeneration at time of release. Stands with the tallest regeneration at time of release produced the largest yields for a given site quality and number of years since harvesting. A 3-m increase in advance-regeneration height resulted in a similar yield gain as a 3-m increase in site index. Site indices calculated from age-height relationships of dominant trees originating from tall advance regeneration were less than those calculated from trees that have undergone a relatively short period of suppression. These results suggest that traditional management tools developed for fire-origin black spruce stands, i.e., stands mainly composed of seed-origin trees established after perturbation, should be adjusted for clearcut-origin stands that largely develop from advance regeneration.

Base-Age Invariant Polymorphic Site Index Curves for Black Spruce and Balsam Fir Within Central Newfoundland

1992 ◽  
Vol 9 (1) ◽  
pp. 18-22 ◽  
Author(s):  
Peter F. Newton
Keyword(s):  
Black Spruce ◽  
Predictive Ability ◽  
Site Index ◽  
Polymorphic Site ◽  
Balsam Fir ◽  
Growth And Yield ◽  
Parameter Estimates ◽  
Prediction Errors ◽  
Site Class ◽  
Permanent Sample Plots

Abstract Increasing management intensity within Newfoundland requires that regional site index equations be species-specific and base-age invariant. Accordingly, base-age invariant polymorphic site index curves for black spruce and balsam fir were developed for use on upland mineral sites within central insular Newfoundland. Specifically, employing mean dominant height and breast-height age data derived from 129, 0.081 ha permanent sample plots situated in pure black spruce (n = 71) and mixed black spruce/balsam fir (n = 58) stands, site index equations were calibrated by species and stand type. In addition, given the approximate numeric equivalence of the resultant parameter estimates, data for both species and stand types were combined and a pooled equation calibrated. The equations were evaluated on their bias and predictive ability over 10-, 20-, and 30-year projection periods. Results indicated that the predictions were positively biased averaging +1.29 m, +2.36 m, and +3.15 m for 10-, 20-, and 30-year projection periods, respectively. Corresponding 95% prediction error intervals for these periods were -0.56 to +3.14 m, -0.88 to +5.44 m, and -1.27 to +6.56 m. These biases and prediction errors are within acceptable limits for site-class designations; however, explicit use of the site-index equations with growth and yield models would depend on error tolerances specified by individual users. North. J. Appl. For. 9(1):18-22

Lumber grade yield, and value of plantation-grown black spruce from 3 stands in northwestern Ontario

2009 ◽  
Vol 85 (4) ◽  
pp. 609-617 ◽  
Author(s):  
Douglas E.B. Reid ◽  
Steven Young ◽  
Queju Tong ◽  
S Y Zhang ◽  
Dave M Morris
Keyword(s):  
Black Spruce ◽  
Site Index ◽  
Modulus Of Rupture ◽  
Intensive Silviculture ◽  
Bending Modulus ◽  
Northwestern Ontario ◽  
Second Growth ◽  
Spruce Stands ◽  
Design Values

Three black spruce plantations in northwestern Ontario, with varied stand densities and site indices were studied to determine lumber properties and yield. Based on visual grading rules, each stand produced at least 87% No. 2 and Better grade lumber. Wane and skip were the 2 most prominent defects causing lumber downgrades. The compliance of visually graded No. 2 and Better lumber with bending modulus of elasticity (MOE) design values for visual grades varied among stands, as did the proportion that qualified as machine stress-rated (MSR) lumber. MOE and Modulus of Rupture (MOR) differed among stands, consistent with differences in MSR yield. The stand with the highest density and the lowest site index produced the highest yield of MSR grade lumber, but not the highest compliance with bending MOE design values. Regardless of the grading scenario, the most productive stand with the largest average tree size produced the highest value per hectare ($28K per ha) under an MSR grading scenario. These results suggest that MSR grading can improve revenues, and that it will be needed to maintain market confidence in the quality of lumber from second-growth black spruce stands. Key words: lumber quality, Picea mariana (Mill.) BSP, market value, density regulation, stand-level effects, intensive silviculture

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