scholarly journals Procedure for developing a site index estimating system from stem analysis data /

1963 ◽  
Author(s):  
Floyd A. Johnson ◽  
Norman P. Worthington ◽  
Keyword(s):  
Analysis Data ◽  
Site Index ◽  
Stem Analysis ◽  
A Site

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.

Comparison and Development of Height Growth and Site Index urves for Douglas-Fir in the Inland Northwest

1989 ◽  
Vol 4 (3) ◽  
pp. 85-88
Author(s):  
James L. Vander Ploeg ◽  
James A. Moore
Keyword(s):  
Pseudotsuga Menziesii ◽  
Model Development ◽  
Analysis Data ◽  
Site Index ◽  
Height Growth ◽  
Douglas Fir ◽  
Western Montana ◽  
Stem Analysis ◽  
Inland Northwest ◽  
Central Idaho

Abstract Stem analysis data from Douglas-fir (Pseudotsuga menziesii) collected throughout the inland Northwest were used for testing height growth and site index equations. The equations performed well in northern and central Idaho, northeast Oregon, and northeast Washington on vegetative types similar to those sampled in model development. However, if the equations were applied on drier sites outside the original geographic study area, overestimates of height growth and under-estimates of site index could result. Therefore, revised height growth and site index equations are presented for western Montana and central Washington. West. J. Appl. For. 4(3):85-88, July 1989.

Site Index Curves for Loblolly Pine Plantations on Cutover Site-Prepared Lands

1985 ◽  
Vol 9 (3) ◽  
pp. 166-169 ◽  
Author(s):  
Ralph L. Amateis ◽  
Harold E. Burkhart
Keyword(s):  
Differential Equation ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Analysis Data ◽  
Site Index ◽  
Height Growth ◽  
Pine Plantations ◽  
The South ◽  
Stem Analysis ◽  
Natural Range

Abstract Stem analysis data collected from dominant and codominant loblolly pine (Pinus taeda) trees in cutover, site-prepared plantations were used to develop site index curves. The data were collected over much of the natural range of loblolly pine. A separable differential equation which expresses height growth as a function of both height and age was used to develop the site index curves. These site index curves should be applicable to loblolly pine plantations on cutover, site-prepared lands through much of the South.1

A comparison of alternative data sources for modeling site index in loblolly pine plantations

2015 ◽  
Vol 45 (8) ◽  
pp. 1026-1033 ◽  
Author(s):  
Micky G. Allen ◽  
Harold E. Burkhart
Keyword(s):  
Loblolly Pine ◽  
Growth Pattern ◽  
Analysis Data ◽  
Site Index ◽  
Height Growth ◽  
Data Sources ◽  
Sample Plot ◽  
Stem Analysis ◽  
Permanent Sample Plots ◽  
Cost Constraints

Site index curves are generally developed from one of three data sources: (i) permanent sample plots, (ii) temporary sample plots, or (iii) stem analysis data. Permanent sample plots are considered to be the best data source for modeling height–age relationships; however, due to time and cost constraints, analysts may consider using temporary sample plots or stem analysis data for equation fitting. Temporary sample plot and stem analysis data, although more quickly obtained, require assumptions that are often not met when modeling site index. The question becomes how models developed from temporary sample plot or stem analysis data compare with models developed from permanent sample plot data. Data from a region-wide study in loblolly pine (Pinus taeda L.) plantations were used to develop site index curves from each of the three data sources. A form of the Chapman–Richards model was used for all three data sources to guard against confounding and to discern differences among the data sources when modeling height–age relationships. For the comparison and evaluation of behavior of different functions, the Schumacher model was also fitted to the three data sources. Curves developed from temporary sample plot and stem analysis data did not reproduce the height growth pattern exhibited in permanent sample plots, although curves derived from temporary plots were closer to the height growth pattern.

scholarly journals Preliminary site index curves for noble fir from stem analysis data /

1970 ◽  
Author(s):  
Donald J. DeMars ◽  
John F. Bell ◽  
Francis R. Herman ◽  
Keyword(s):  
Analysis Data ◽  
Site Index ◽  
Stem Analysis ◽  
Noble Fir

Estimating Site Quality of Young Red Pine Plantations by Growth Intercept Methods

1988 ◽  
Vol 5 (2) ◽  
pp. 91-93 ◽  
Author(s):  
Timothy R. Bottenfield ◽  
David D. Reed
Keyword(s):  
Analysis Data ◽  
Site Index ◽  
Height Growth ◽  
Red Pine ◽  
Pine Plantations ◽  
Site Quality ◽  
Stem Analysis ◽  
Breast Height ◽  
Growth Intercept

Abstract Five growth intercept measurements were correlated with site index of red pine plantations in the northern Lakes States. The growth intercept variables were obtained by direct field measurement or indirectly through interpolation of stem analysis data. Growth intercepts represented both time (age in years) and distance (height in feet) measurements. Growth intercepts representing time and the age at breast height are not recommended for use in young red pine plantations. The amount of height growth in the first five annual whorls above 5 and 8 ft were good predictors of site index. North. J. Appl. For. 5:91-93, June 1988.

Site Index and Height Growth Curves for Ponderosa Pine, Western Larch, Lodgepole Pine, and Douglas-Fir in Western Montana

1992 ◽  
Vol 7 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Kelsey S. Milner
Keyword(s):  
Ponderosa Pine ◽  
Growth Curves ◽  
Analysis Data ◽  
Site Index ◽  
Height Growth ◽  
Douglas Fir ◽  
Growth Patterns ◽  
Western Montana ◽  
Stem Analysis ◽  
Western Larch

Abstract Height growth patterns from several published site curve sytems for ponderosa pine (Pinus ponderosa), Douglas-fir (Pseudotsuga menziesii var glauca), western larch (Larix occidentalis) and lodgepole pine (Pinus contorta var latifolia) were compared to stem analysis data from western Montana. Most of the published curves had height growth patterns that differed significantly from those in the data. The magnitude of the deviations often varied by level of site index; this appeared to be related to differences in the range of site qualities sampled. Those curves constructed from stem analysis data from geographically similar populations compared most closely. Curves constructed using guide curve techniques showed a consistent tendency to underpredict heights at greater ages. New site index and height growth curves are presented for each species. West. J. Appl. For. 7(1):9-14.

A Sitka spruce height-age model with improved extrapolation properties

1997 ◽  
Vol 73 (3) ◽  
pp. 363-369 ◽  
Author(s):  
Gordon D. Nigh
Keyword(s):  
British Columbia ◽  
Serial Correlation ◽  
Sitka Spruce ◽  
Analysis Data ◽  
Site Index ◽  
Picea Sitchensis ◽  
Stem Analysis ◽  
Queen Charlotte Islands ◽  
Extrapolation Model ◽  
Age Model

The height-age model for Sitka spruce (Picea sitchensis (Bong.) Carr.) currently recommended for use in British Columbia has poor extrapolation properties. Therefore, a new height-age model for Sitka spruce using stem analysis data collected from the Queen Charlotte Islands was developed. Care was taken to meet the standard regression assumptions. In particular, accounting for within-plot serial correlation improved the extrapolation abilities of the model by eliminating the crossing-over effect. The new model is being recommended for use in British Columbia because it offers better extrapolated height and site index estimates without sacrificing accuracy at young ages. Key words: Sitka spruce, site index, height-age model, serial correlation, nonlinear regression, extrapolation, model properties

scholarly journals A closer look at site index - biogeoclimatic site series correlations: Douglas-fir in the Coastal Western Hemlock Zone, xm2 variant, 01 site series

2010 ◽  
Vol 86 (4) ◽  
pp. 477-483 ◽  
Author(s):  
Gord Nigh
Keyword(s):  
Site Index ◽  
Douglas Fir ◽  
Stem Analysis ◽  
Data Set ◽  
Site Specific ◽  
Index Site ◽  
Ecosystem Classification ◽  
Age Model ◽  
A Site ◽  
Index Estimate

The Site Index - Biogeoclimatic Ecosystem Classification (SIBEC) model predicts site index from species and biogeoclimatic site series. The purpose of this project was, for Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii) in the CWHxm2/01 site series, to: 1) verify that the current SIBEC site index estimate of 32.90 m is accurate, 2) create a more site-specific SIBEC model by including additional variables in the model to capture within-site series variation, and 3) compare the SIBEC site index estimates and their variability when the estimates are obtained using stem analysis data versus data from Bruce’s (1981) height-age model. The data set consisted of 40 Douglas-fir plots established in the CWHxm2/01 site series. The analysis shows that the current SIBEC site index estimate should be changed to 34.68 m. No relationship was found between site index and ecological variables within this site series, hence the model could not be made more site-specific. The BEC system aggregates sites into relatively homogeneous units with respect to productivity. The comparison of the SIBEC site index estimates and their variances when estimated using stem analysis and a height-age model were not statistically different. Obtaining a site index estimate from Bruce’s model is as accurate as obtaining a site index estimate from stem analysis when the Douglas-fir sample trees are between 50 and 80 years of age.Key words: Biogeoclimatic Ecosystem Classification, Douglas-fir, model error, site index, site series, stem analysis

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.

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