Dominant-height and site-index equations for ponderosa pine in east-central Arizona

1991 ◽  
Vol 21 (5) ◽  
pp. 606-611 ◽  
Author(s):  
W. F. Stansfield ◽  
J. P. McTague ◽  
R. Lacapa
Keyword(s):  
Ponderosa Pine ◽  
Habitat Type ◽  
Prediction Method ◽  
Site Index ◽  
Site Quality ◽  
Predictive Capability ◽  
East Central ◽  
Dominant Height ◽  
Central Arizona ◽  
Parameter Prediction

A dominant-height equation for ponderosa pine (Pinusponderosa Laws.) was constructed utilizing a parameter prediction method and a model by J.E. King. The site-index equation was obtained by inverting the dominant-height equation. A method was examined for indirectly obtaining parameter prediction equations. It proved superior to two direct parameter prediction approaches. Other site-quality variables, such as habitat type groups and elevation, were included in the dominant-height and site-index equations and were successful in refining predictive capability.

Dominant Height and Site Index Equations for Douglas-Fir and Engelmann Spruce in East-Central Arizona

1992 ◽  
Vol 7 (2) ◽  
pp. 40-44 ◽  
Author(s):  
W. F. Stansfield ◽  
J. P. McTague ◽  
R. Lacapa
Keyword(s):  
Habitat Type ◽  
Prediction Method ◽  
Analysis Data ◽  
Site Index ◽  
Douglas Fir ◽  
East Central ◽  
Engelmann Spruce ◽  
Dominant Height ◽  
Fort Apache Indian Reservation ◽  
Central Arizona

Abstract Dominant height and site index equations were constructed for Douglas-fir (Pseudotsuga menziesii var. glauca) and Engelmann spruce (Picea engelmannii) on the Fort Apache Indian Reservation, located in east-central Arizona. An indirect parameter prediction method was utilized to develop the equations from stem analysis data. The dominant height equation for Douglas-fir is a function of site index, age, habitat type groups, and soil texture groups. The Engelmann spruce dominant height equation is a function of only site index and age. Site index may be calculated directly by inverting the dominant height equations. West. J. Appl. For. 7(2):40-44.

Ponderosa Pine Habitat Types as an Indicator of Site Quality in the Dixie National Forest, Utah

1989 ◽  
Vol 4 (2) ◽  
pp. 52-54 ◽  
Author(s):  
David L. Verbyla ◽  
Richard F. Fisher
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Tree Species ◽  
Habitat Type ◽  
Site Index ◽  
Site Quality ◽  
National Forest ◽  
Habitat Types ◽  
Quercus Gambelii ◽  
Generally True

Abstract Forest habitat types have been purported to be useful indicators of site quality. This is generally true for habitat types with different dominant tree species. However, few have studied the site indicator value of habitat types with the same dominant tree species. We measured site index (base age 25) from 172 randomly selected plots within the ponderosa pine (Pinus ponderosa) zone of the Dixie National Forest, Utah. The range of site index within any one habitat type was broad. Poor sites occurred on all five habitat types. However, the best sites occurred only on the Pinus ponderosa/Symphoricarpos oreophilus and Pinus ponderosa/Quercus gambelii habitat types. Therefore, habitat type may be useful in predicting the best sites, but only if other site information is used in addition to habitat type. West. J. Appl. For. 4(2):52-54, April 1989.

scholarly journals Effects of Stand Density on Top Height Estimation for Ponderosa Pine

2012 ◽  
Vol 27 (1) ◽  
pp. 18-24 ◽  
Author(s):  
Martin Ritchie ◽  
Jianwei Zhang ◽  
Todd Hamilton
Keyword(s):  
Ponderosa Pine ◽  
Stand Density ◽  
Tree Height ◽  
Site Index ◽  
Fixed Number ◽  
Site Quality ◽  
Height Estimation ◽  
Growing Stock ◽  
Dominant Height ◽  
Definition Of

Abstract Site index, estimated as a function of dominant-tree height and age, is often used as an expression of site quality. This expression is assumed to be effectively independent of stand density. Observation of dominant height at two different ponderosa pine levels-of-growing-stock studies revealed that top height stability with respect to stand density depends on the definition of the dominant height. Dominant height estimates calculated from a fixed number of trees per acre (ranging from 10 to 60 of the tallest trees per acre) were less affected by density than those calculated from a proportion (with the cutoff ranging from 95th to the 70th percentile) of the largest trees in the stand.

Suitability of two methods of evaluating site quality for sugar maple in central Ontario

2006 ◽  
Vol 82 (5) ◽  
pp. 733-744 ◽  
Author(s):  
Nicholas J Buda ◽  
Jian R Wang
Keyword(s):  
Sugar Maple ◽  
Quality Evaluation ◽  
Growth Models ◽  
Site Index ◽  
Height Growth ◽  
Site Quality ◽  
Dominant Height ◽  
Index Site ◽  
Species Mixture ◽  
Stand Conditions

Stem analyses data collected in central Ontario stands were used to develop site index (height and age) and site form (height and diameter) models and curves for sugar maple. The suitability of both methods for evaluating sugar maple site productivity was examined. Two different equation forms were evaluated for both site index and site form models. A common modification of Richard's (1959) equation was most suitable for predicting dominant height at index age (site index) and reference diameter (site form). Potential effects of species mixture on sugar maple site index were examined. We found no significant effects on sugar maple height growth and site index in mixed stand conditions common in the region when compared to pure stands. The potential of site form as an alternative to site index was investigated through correlation analyses with site index and other site variables known to influence sugar maple height growth. Site form was not related to site index, nor any site variables related to sugar maple height growth. It is therefore inadequate for evaluating sugar maple site quality. We recommend height growth models and site index curves developed in this study be used to replace those from other regions currently used in central Ontario. Key words: site index, site form, sugar maple, site quality evaluation, mixedwood, uneven-aged

Assessing the effect of measurement error in age on dominant height and site index estimates

2011 ◽  
Vol 41 (8) ◽  
pp. 1698-1709 ◽  
Author(s):  
Chengcai Ni ◽  
Gordon Nigh
Keyword(s):  
Measurement Error ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Site Index ◽  
Stand Age ◽  
Initial Value ◽  
Dominant Height ◽  
Projection Length ◽  
Age Model ◽  
Projection Error

Stand age is often hard to measure accurately. Measurement error in age affects height estimates when height is projected from one age to another age. In this study, our objective was to derive an estimator for the variance of the component of projection error associated with the error in age. To evaluate the estimator, a simulation approach was employed and the results showed that the estimator worked well in most cases. When the variance of the error in age increases and the projection is forward, however, the estimator might not work as well as in other cases. Another objective was to examine how the error in age behaved under different height–age models and to what extent it affected height and site index estimates. The effect of the error in age depended on its magnitude, the height–age model, initial value of dominant height and age, and projection length. It was also shown that the effect was sometimes negligible, but it could be considerable in other cases. Data from 80 ponderosa pine ( Pinus ponderosa Dougl. ex Laws.) trees in British Columbia, Canada, were used in an illustrative example.

Reevaluating the self-thinning boundary line for ponderosa pine (Pinus ponderosa) forests

2013 ◽  
Vol 43 (10) ◽  
pp. 963-971 ◽  
Author(s):  
Jianwei Zhang ◽  
William W. Oliver ◽  
Robert F. Powers
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Stochastic Frontier ◽  
Site Occupancy ◽  
Stand Density ◽  
Site Index ◽  
The Self ◽  
Site Quality ◽  
Boundary Line ◽  
The Face

The self-thinning rule has been used extensively to predict population dynamics under intraspecific and interspecific competition. In forestry, it is an important silvicultural concept for maintaining stand health in the face of climate change and biotic stress, but uncertainty exists because traditional self-thinning limits were set subjectively without regard to site quality. We addressed this by analyzing ponderosa pine (Pinus ponderosa Lawson & C. Lawson) data from 109 research plots measured repeatedly and 59 inventory plots measured once across California. Self-thinning boundaries were fitted to the data with quantile regression and stochastic frontier function (SFF) techniques with and without site index (SI) as a covariate. The models from both methods fitted the data well with either research plots or all plots. Slopes for size-density trajectories were –0.45 with the 0.99 quantile and –0.47 for SFF. Maximum stand density indices (SDI) were 1250 trees per hectare (TPH) with the 0.99 quantile and 1050–1060 TPH with SFF. Mortality occurred when site occupancy from SFF reached 0.75, suggesting a zone of imminent mortality. Curvilinear trends in maximum SDI across SI for both methods indicate that self-thinning varies with site quality. Any management regimes that increase site quality and productivity will increase the self-thinning boundary.

scholarly journals Assessing site form as an indicator of site quality in even-aged Pinus radiata D. Don stands in north-western Spain

2019 ◽  
Vol 76 (4) ◽  
Author(s):  
Juan Alberto Molina-Valero ◽  
Ulises Diéguez-Aranda ◽  
Juan Gabriel Álvarez-González ◽  
Fernando Castedo-Dorado ◽  
César Pérez-Cruzado
Keyword(s):  
Pinus Radiata ◽  
Goodness Of Fit ◽  
Model Fitting ◽  
Site Index ◽  
Site Quality ◽  
Stand Age ◽  
Fit Statistics ◽  
Dominant Height ◽  
Western Spain ◽  
North Western

Abstract Key message Site form and site index have shown similar precision for estimating site quality in even-agedPinus radiataD. Don stands in north-western Spain. Additionally, SF presents the advantage that it does not require stand age information and can therefore be used in a wider set of situations in the forestry practice. Context Estimation of site quality is essential for characterizing, monitoring and predicting forest resources. Site index (i.e. the dominant height of the stand at a reference age) is ordinarily used to estimate site quality; however, this index is only useful for even-aged stands of known age. By contrast, SF is age-independent as it uses the dominant height of the stand at a reference dominant diameter. Aims The aim of this study was to compare the performance of SF and SI for site quality estimation in even-aged P. radiata stands. Methods Dynamic equations derived with the Generalized Algebraic Difference Approach (GADA) from the Hossfeld IV base model were fitted to predict site quality with both SI and SF. SF predictions were compared with SI regarding variability within the same plot and consistency in site quality predictions, using the observed maximum mean annual volume increment (MAI) as a direct measure of site quality. Results Both approaches showed good performance in model fitting and provided similar goodness-of-fit statistics and variability in the predictions. However, SI performed slightly stronger when related to MAI. Conclusion SF performed adequately in estimating site quality for even-aged P. radiata stands, with results comparable to those obtained using traditional SI.

scholarly journals GROWTH AND YIELD OF EVEN-AGED Cupressus lusitanica PLANTATIONS IN SOUTHERN BRAZIL

FLORESTA ◽  
2021 ◽  
Vol 51 (4) ◽  
pp. 980
Author(s):  
Mário Dobner Jr.
Keyword(s):  
Basal Area ◽  
Site Index ◽  
Growth And Yield ◽  
Site Quality ◽  
Timber Species ◽  
Southern Brazil ◽  
Cupressus Lusitanica ◽  
Dominant Height ◽  
Dominant Height Growth ◽  
Quality Variation

Plantation forestry in southern Brazil demands additional timber species to a higher market differentiation by providing high quality timber and exploitation of market niches. Cupressus lusitanica has long been recognized for this purpose but, until now, it was not properly region-wide quantified in terms of growth and yield. The present study delivers the lacking quantitative approach, which may encourage the commercial use of the species. With this study it was aimed at collecting and processing quantitative data from all known C. lusitanica stands in southern Brazil. Inventories were carried out (60 ha, 6-39 years of age) in order to model the development of dominant height (h100), basal area, volume and dominant diameter (d100). Dominant height was the basis for site quality evaluation, delivering site index curves, which, together with the commercial volume of the stands, allowed yield modelling. A wide amplitude of dominant height growth was detected (10-30 m at 20 years), indicating a great site quality variation. At age of 20 years, commercial volumes of 110 and 620 m³ ha-1 were observed for site indexes of 14 and 26, respectively, equivalent to a maximum of 6-31 m³ ha-1 year-1 at ages between 16-18 years. Results demonstrated in a robust manner that C. lusitanica has a high potential for cultivation in southern Brazil. Thus, offering the opportunity of market differentiation by promoting market niches whose demands timber for special solid end-uses.

scholarly journals SITE INDEX IN EUCALYPTUS STANDS APPLYING ORDINARY KRIGING: AN APPROACH WITH DIFFERENT MODELS AND METHODS OF CLASSIFICATION

FLORESTA ◽  
2021 ◽  
Vol 51 (4) ◽  
pp. 1000
Author(s):  
Pedro Vaz da Rocha ◽  
Emanuel José Gomes de Araújo ◽  
Vinícius Augusto Morais ◽  
Marco Antonio Monte ◽  
Danilo Henrique dos Santos Ataíde ◽  
...  
Keyword(s):  
Difference Method ◽  
Spatial Dependence ◽  
Ordinary Kriging ◽  
Gaussian Model ◽  
Site Index ◽  
Site Quality ◽  
Productive Capacity ◽  
Dominant Height ◽  
Algebraic Difference ◽  
Predictive Validation

The objective of this work was to evaluate the efficiency of models and methods to obtain the site index, associated with ordinary kriging, to classify productive capacity in eucalyptus stands. Thus, the site quality was performed considering the traditional modeling in clonal stands (2,119 hectares) located in Minas Gerais state, Brazil. 170 plots of 400m2 were randomly allocated, representing a sampling intensity of 0.32%. The dominant height of trees (Assmann) was measured at 24, 36, 48, 60, 72, and 84 months. The site index (S) was estimated by the guide curve and algebraic difference methods, using the models of Schumacher, Chapman and Richards, and Bailey and Clutter. 136 plots were used in the fit and 34 plots in the predictive validation. The spatial dependence of site index was evaluated by experimental semivariogram and adjustment of exponential, spherical, and gaussian models. After confirming the spatial dependence, ordinary kriging was performed to spatialize the site index. For the predictive validation, the dominant height values at 72 months were used. The algebraic difference method provided excellent estimates of site index, which showed spatial dependence in all adjustments, from moderate to strong. In most cases, the gaussian model was the most accurate. It is concluded that the algebraic difference method was more efficient and the site index showed strong spatial dependence at all ages, regardless of the model used. Thus, regression models for site index estimation can be used in combination with ordinary kriging techniques.

scholarly journals SITE QUALITY CURVES FOR AFRICAN MAHOGANY PLANTATIONS IN BRAZIL

CERNE ◽  
2016 ◽  
Vol 22 (4) ◽  
pp. 439-448 ◽  
Author(s):  
Andressa Ribeiro ◽  
Antonio Carlos Ferraz Filho ◽  
Margarida Tomé ◽  
José Roberto Soares Scolforo
Keyword(s):  
Site Index ◽  
Growth And Yield ◽  
Site Quality ◽  
Site Classification ◽  
Site Class ◽  
African Mahogany ◽  
Dominant Height ◽  
Curve Method ◽  
Dominant Height Growth ◽  
The Stability

ABSTRACT Site quality estimation is an important tool in forest management since it is useful for modeling growth and yield for even-aged stands. Data from African mahogany (Khaya ivorensis A. Chev.) Brazilian plantations were used to develop a model to predict dominant height growth, comparing dynamic base-age invariant site index models with the guide curve method (static models). For the evaluation of the candidate models qualitative and quantitative criteria were used. We also verified the stability of the candidate models, preferring a model providing fewer site class changes when predicting site index from different ages. The Lundqvist-Korf function fitted with the guide curve method proved to be effective and accurate for site classification and dominant height predictions of African mahogany stands. The range of observed site index, at a reference age of 15, was between 17 and 33 meters.

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