Assessing the Accuracy of a Product-form Tree Volume Equation

1981 ◽  
Vol 57 (3) ◽  
pp. 119-122
Author(s):  
Peter Roebbelen ◽  
Victor G. Smith

In a continuing investigation of product-form as a predicting variable in volume estimation, this study compares a product-form tree volume equation with two standard volume equations and the Dominion Forestry Service form-class 70 and 75 volume tables in their ability to estimate individual tree red pine volumes. Using weighted regression and measurements from 3607 individual trees, coefficients for the three equations were developed. Freese's test of accuracy was used as the criterion of choice in deciding which method proved most accurate in estimating the volumes of a set of test data.The product-form volume equation gave the most accurate estimates.

1973 ◽  
Vol 3 (3) ◽  
pp. 338-341
Author(s):  
F. Evert

Three form-class volume equations involving the upper stem diameter at 19.5 ft (5.94 m) above ground level and three standard volume equations based on d.b.h. and height were tested for accuracy in estimating both tree and stand volume in different stands of red pine (Pinusresinosa Ait.). All three form-class equations met the required 10% accuracy in estimating individual tree volumes; the three standard volume equations failed to meet this accuracy. All three form-class equations also met the required 5% accuracy in estimating stand volume, but none of the standard equations did.


1995 ◽  
Vol 25 (11) ◽  
pp. 1783-1794 ◽  
Author(s):  
Thomas B. Lynch

Three basic techniques are proposed for reducing the variance of the stand volume estimate provided by cylinder sampling and Ueno's method. Ueno's method is based on critical height sampling but does not require measurement of critical heights. Instead, a count of trees whose critical heights are less than randomly generated heights is used to estimate stand volume. Cylinder sampling selects sample trees for which randomly generated heights fall within cylinders formed by tree heights and point sampling plot sizes. The methods proposed here for variance reduction in cylinder sampling and Ueno's method are antithetic variates, importance sampling, and control variates. Cylinder sampling without variance reduction was the most efficient of 12 methods compared in computer simulation that used estimated measurement times. However, cylinder sampling requires knowledge of a combined variable individual tree volume equation. Of the three variance reduction techniques applied to Ueno's method, antithetic variates performed best in computer simulation.


1997 ◽  
Vol 14 (2) ◽  
pp. 53-58 ◽  
Author(s):  
Gary W. Fowler

Abstract New total, pulpwood, sawtimber, and residual pulpwood cubic foot individual tree volume equations were developed for red pine in Michigan using nonlinear and multiple linear regression. Equations were also developed for Doyle, International 1/4 in., and Scribner bd ft volume, and a procedure for estimating pulpwood and residual pulpwood rough cord volumes from the appropriate cubic foot equations was described. Average ratios of residual pulpwood (i.e., topwood, cubic foot or cords) to mbf were developed for 7.6 and 9.6 in. sawtimber. Data used to develop these equations were collected during May-August 1983-1985 from 3,507 felled and/or standing trees from 27 stands in Michigan. Sixteen and 11 stands were located in the Upper and Lower Peninsulas, respectively. All equations were validated on an independent data set. Rough cord volume estimates based on the new pulpwood equation were compared with contemporary tables for 2 small cruise data sets. The new equations can be used to more accurately estimate total volume and volume per acre when cruising red pine stands. North. J. Appl. For. 14(2):53-58.


2008 ◽  
Vol 25 (3) ◽  
pp. 151-153 ◽  
Author(s):  
Lichun Jiang ◽  
John R. Brooks

Abstract Compatible taper, volume, and weight equations were developed for planted red pine in West Virginia. The data were based on stem analysis of 26 trees from West Virginia University Research Forest, located in northern West Virginia. A commonly used segmented polynomial taper equation was chosen because of its balance between prediction accuracy and ease of use. Seemingly unrelated regression was used to simultaneously fit the system of equations for inside and outside bark data. When compared with existing total stem volume equations developed by Fowler (Fowler, G.W., 1997, Individual tree volume equations for red pine in Michigan, North. J. Appl. For. 14:53–58) and by Gilmore et al. (Gilmore, D.W., et al., 2005, Thinning red pine plantations and the Langsaeter hypothesis: A northern Minnesota case study. North, J. Appl. For. 22:19–25), a positive bias was evident that increased directly with stem diameter for trees from this region.


1990 ◽  
Vol 20 (3) ◽  
pp. 274-279 ◽  
Author(s):  
Thomas B. Lynch

Stand volume estimators are developed in the context of vertical line sampling that depend on counts of sample trees only, rather than on measurements of sample tree dimensions. These estimators are based on three commonly used individual tree volume equations: the constant form factor volume equation, the combined variable volume equation with negative intercept, and the combined variable volume equation with positive intercept. Fieldwork for each of the estimators involves comparison of the squared dbh's of trees that would qualify for selection in an ordinary vertical line sample with numbers chosen randomly from the interval bounded by zero and a fixed maximum squared dbh. Two of the estimators choose sample trees with probability exactly proportional to an individual tree volume equation.


1989 ◽  
Vol 65 (2) ◽  
pp. 102-106 ◽  
Author(s):  
Bijan Payandeh

Stem analyse of 67 peatland black spruce trees from previously drained experimental areas in northeastern Ontario that had been fertilized was used to examine effects on growth of individual trees. Stepwise multiple linear regression analysis was used to express pre- and post-fertilization diameter and volume growth as a function of site, stand and individual tree characteristics and amelioration treatments.Results indicated that, on average, diameter growth increased by 4% after fertilization. Standard volume equations, in comparison with sectional volume summation underestimated both inside- and outside-bark tree volumes by about 3%.


1983 ◽  
Vol 13 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Riyaz A. Sadiq ◽  
Victor G. Smith

Even though invention of high-precision equipment has reduced measurement errors associated with the estimation of heights of standing trees, height estimation is still an expensive and time-consuming operation. At times it is difficult to determine especially in dense forests or in forests located in hilly terrain. The present study advocates a volume–age–diameter function to estimate volumes of individual trees. The technique presented here circumvents measurement of tree heights through the use of age which, however, restricts the application of the function to plantations or forests whose age is predetermined. Analyses with stem-analysis data from red pine (Pinusresinosa Ait.) plantations of southern Ontario indicate that the function estimates tree volumes more accurately than the standard methods commonly used.


1994 ◽  
Vol 24 (6) ◽  
pp. 1289-1294 ◽  
Author(s):  
Kazukiyo Yamamoto

A simple system for the estimation of stem volume is presented based on the compatible stem profile and volume equations. This system can directly predict the stem volume above breast height from measurements of stem diameter at breast height and at an another point along the upper stem, and does not require any sample data for determining a parameter of volume equation. In comparison with the prediction accuracy of existing volume equations from the literature, using data from Cryptomeriajaponica D. Don, Chamaecyparisobtsusa Endl., and Pseudotsugamenziesii (Mirb.) Franco, this system has the advantage of reducing prediction error.


1983 ◽  
Vol 59 (1) ◽  
pp. 26-29 ◽  
Author(s):  
F. Evert

A stand volume equation is presented for black spruce (Picea mariana (Mill.)B.S.P.), based on a sample of 785 felled trees. To ensure that the equation will provide accurate estimates of the volume of both variously stocked stands and of individual trees, stand volume was expressed as the sum of individual tree volumes without direct reference to the size of the area that the trees occupy. The equation will reduce the problem of forecasting stand volume to the simpler problem of forecasting separately the individual components in the stand-volume equation.


2006 ◽  
Vol 36 (5) ◽  
pp. 1190-1205 ◽  
Author(s):  
Ulises Diéguez-Aranda ◽  
Fernando Castedo-Dorado ◽  
Juan Gabriel Álvarez-González ◽  
Alberto Rojo

A compatible system for estimation of individual tree volume was developed for Scots pine (Pinus sylvestris L.) in northwestern Spain. The system comprises a merchantable volume equation, a total volume equation, and a taper function. The use of the volume equation allows rapid estimation of tree volume, and stand volume by summing individual tree volumes, which is equal to the volume obtained by integrating the taper equation. The volume equation is very easy to use and is therefore preferred when classification of the products by merchantable sizes is not required. Data from 228 destructively sampled trees were used for model development. Fourteen compatible volume equations were evaluated, 13 of these equations were taken from the available literature, and the other was developed in the present study. A modified second-order continuous autoregressive error structure was used to correct the autocorrelation of the hierarchical data used. The model developed by Fang et al. (Z. Fang, B.E. Borders, and R.L. Bailey. 2000. For. Sci. 46: 1–12) best described the data. There model is therefore recommended for the estimation of diameter at a specific height, merchantable volume, and total volume of Scots pine stems in the area of study.


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