New Form-class Equations Improve Volume Estimates

1973 ◽  
Vol 3 (3) ◽  
pp. 338-341
Author(s):  
F. Evert
Keyword(s):  
Ground Level ◽  
Red Pine ◽  
Stem Diameter ◽  
Individual Tree ◽  
Stand Volume ◽  
Above Ground Level ◽  
Form Class ◽  
New Form ◽  
Volume Estimates ◽  
Volume Equations

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.

scholarly journals Individual Tree Volume Equations for Red Pine in Michigan

1997 ◽  
Vol 14 (2) ◽  
pp. 53-58 ◽  
Author(s):  
Gary W. Fowler
Keyword(s):  
Red Pine ◽  
Data Sets ◽  
Regression Equations ◽  
Independent Data ◽  
Data Set ◽  
Individual Tree ◽  
Standing Trees ◽  
Pine Stands ◽  
Volume Estimates ◽  
Volume Equations

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.

Assessing the Accuracy of a Product-form Tree Volume Equation

1981 ◽  
Vol 57 (3) ◽  
pp. 119-122
Author(s):  
Peter Roebbelen ◽  
Victor G. Smith
Keyword(s):  
Volume Estimation ◽  
Red Pine ◽  
Product Form ◽  
Weighted Regression ◽  
Individual Tree ◽  
Form Class ◽  
Volume Equation ◽  
Individual Trees ◽  
Volume Equations

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.

scholarly journals Taper, Volume, and Weight Equations for Red Pine in West Virginia

2008 ◽  
Vol 25 (3) ◽  
pp. 151-153 ◽  
Author(s):  
Lichun Jiang ◽  
John R. Brooks
Keyword(s):  
West Virginia ◽  
Ease Of Use ◽  
Red Pine ◽  
Seemingly Unrelated Regression ◽  
Stem Volume ◽  
West Virginia University ◽  
Individual Tree ◽  
Unrelated Regression ◽  
Taper Equation ◽  
Volume Equations

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.

Compatible Tree Volume and Taper Functions for Pitch Pine

1985 ◽  
Vol 2 (1) ◽  
pp. 14-16 ◽  
Author(s):  
Edwin J. Green ◽  
David D. Reed
Keyword(s):  
Volume Ratio ◽  
Stem Diameter ◽  
Individual Tree ◽  
Pitch Pine ◽  
Volume Equations

Abstract Individual tree taper, volume ratio, and total volume equations are presented for pitch pine. The volume ratio equations may be used to determine merchantable volume to any height or upper stem diameter. The equations are compatible and are based on a recommended taper curve. Examples of how to employ the equations are presented. North J. Appl. For. 2:14-16, Mar. 1985.

Individual Tree Volume Equations for the Northeastern United States: Evaluation and New Form Quotient Board Foot Equations1

1989 ◽  
Vol 6 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Thomas E. Burk ◽  
Richard P. Hans ◽  
Eric H. Wharton
Keyword(s):  
United States ◽  
Northeastern United States ◽  
Individual Tree ◽  
Tree Form ◽  
Forest Survey ◽  
Species Groups ◽  
New Form ◽  
Using Data ◽  
Volume Equations

Abstract Volume equations used in forest survey in the northeastern United States were evaluated using data collected as part of utilization studies. Results are presented for both cubic foot and board foot equations for 16 species groups. Existing cubic foot equations were found to be satisfactory while the board foot equations generally produced significantly large underestimates. New board foot equations that include a measure of tree form were derived. North. J. Appl. For. 6(1):27-31, March 1989.

scholarly journals Mobile Laser Scanning for Estimating Tree Stem Diameter Using Segmentation and Tree Spine Calibration

2019 ◽  
Vol 11 (23) ◽  
pp. 2781 ◽  
Author(s):  
Johan Holmgren ◽  
Michael Tulldahl ◽  
Jonas Nordlöf ◽  
Erik Willén ◽  
Håkan Olsson
Keyword(s):  
Laser Scanning ◽  
Basal Area ◽  
Ground Level ◽  
Stem Diameter ◽  
Global Navigation Satellite Systems ◽  
Individual Tree ◽  
Satellite Systems ◽  
Link Distance ◽  
Laser Data ◽  
Tree Stem

Mobile laser scanning (MLS) could make forest inventories more efficient, by using algorithms that automatically derive tree stem center positions and stem diameters. In this work we present a novel method for calibration of the position for laser returns based on tree spines derived from laser data. A first calibration of positions was made for sequential laser scans and further calibrations of laser returns were possible after segmentation, in which laser returns were associated to individual tree stems. The segmentation made it possible to model tree stem spines (i.e., center line of tree stems). Assumptions of coherent tree spine positions were used for correcting laser return positions on the tree stems, thereby improving estimation of stem profiles (i.e., stem diameters at different heights from the ground level). The method was validated on six 20-m radius field plots. Stem diameters were estimated with a Root-Mean-Square-Error (RMSE) of 1 cm for safely linked trees (maximum link distance of 0.5 m) and with a restriction of a minimum amount of data from height intervals for supporting circle estimates. The accuracy was high for plot level estimates of basal area-weighted mean stem diameter (relative RMSE 3.4%) and basal area (relative RMSE 8.5%) because of little influence of small trees (i.e., aggregation of individual trees). The spine calibration made it possible to derive 3D stem profiles also from 3D laser data calculated from sensor positions with large errors because of disturbed below canopy signals from global navigation satellite systems.

Compatible taper function for Scots pine plantations in northwestern Spain

2006 ◽  
Vol 36 (5) ◽  
pp. 1190-1205 ◽  
Author(s):  
Ulises Diéguez-Aranda ◽  
Fernando Castedo-Dorado ◽  
Juan Gabriel Álvarez-González ◽  
Alberto Rojo
Keyword(s):  
Scots Pine ◽  
Model Development ◽  
Individual Tree ◽  
Stand Volume ◽  
Taper Function ◽  
Northwestern Spain ◽  
Volume Equation ◽  
Taper Equation ◽  
Volume Equations

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.

scholarly journals STRATEGIES FOR STEM MEASUREMENT SAMPLING: A STATISTICAL APPROACH OF MODELLING INDIVIDUAL TREE VOLUME

CERNE ◽  
2016 ◽  
Vol 22 (3) ◽  
pp. 249-260 ◽  
Author(s):  
Hassan Camil David ◽  
Rodrigo Otávio Veiga Miranda ◽  
John Welker ◽  
Luan Demarco Fiorentin ◽  
Ângelo Augusto Ebling ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Statistical Tests ◽  
Fixed Number ◽  
Stem Volume ◽  
Diameter Class ◽  
Clear Trend ◽  
Data Set ◽  
Individual Tree ◽  
Volume Estimates ◽  
Volume Equations

ABSTRACT The aim of this paper was to evaluate different criteria for stem measurement sampling and to identify the criterion with best performance for developing individual tree volume equations. Data were collected in eucalyptus stands 58 to 65 months old. Schumacher-Hall model was applied using five sampling criteria with nine variations (45 in total): 1) number of trees per diameter class, being (a) fixed number, (b) proportional to the diameter class of the sample, or (c) proportional to the standard deviation of the sample; and 2) the width of the diameter class, which ranged from 1.0 up to 5.0 cm. We used the equations generated from each of the five sampling criteria to estimate stem volume of trees reserved for validation. This allowed us to obtain standard errors of estimates from this data-set. In addition, residuals of volume estimates were examined by means of statistical tests of bias, autocorrelation and heteroscedasticity. Better performances of volume equations occurred when smaller diameter class widths were used, i.e., when the sample size increased. There was no clear trend in increasing/decreasing residual autocorrelation and/or heteroscedasticity. Both methods of sampling proportional to the frequency of diameter class had the best performances, inclusive using only 36 trees. The ones where choice of trees was proportional to the standard deviation had the worst. In conclusion, the selection proportional to the frequency of the diameter class, under the condition that at least two trees per class are sampled, provides models statistically better than all the other criteria.

scholarly journals Spatial Analysis (Measurements at Heights of 10 m and 20 m above Ground Level) of the Concentrations of Particulate Matter (PM10, PM2.5, and PM1.0) and Gaseous Pollutants (H2S) on the University Campus: A Case Study

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 62
Author(s):  
Robert Cichowicz ◽  
Maciej Dobrzański
Keyword(s):  
Spatial Distribution ◽  
Hydrogen Sulfide ◽  
Particulate Matter ◽  
Air Quality ◽  
Spatial Analysis ◽  
Ground Level ◽  
Leeward Side ◽  
High Concentration ◽  
Above Ground Level ◽  
High Concentrations

Spatial analysis of the distribution of particulate matter PM10, PM2.5, PM1.0, and hydrogen sulfide (H2S) gas pollution was performed in the area around a university library building. The reasons for the subject matter were reports related to the perceptible odor characteristic of hydrogen sulfide and a general poor assessment of air quality by employees and students. Due to the area of analysis, it was decided to perform measurements at two heights, 10 m and 20 m above ground level, using measuring equipment attached to a DJI Matrice 600 unmanned aerial vehicle (UAV). The aim of the measurements was air quality assessment and investigate the convergence of the theory of air flow around the building with the spatial distribution of air pollutants. Considerable differences of up to 63% were observed in the concentrations of pollutants measured around the building, especially between opposite sides, depending on the direction of the wind. To explain these differences, the theory of aerodynamics was applied to visualize the probable airflow in the direction of the wind. A strong convergence was observed between the aerodynamic model and the spatial distribution of pollutants. This was evidenced by the high concentrations of dust in the areas of strong turbulence at the edges of the building and on the leeward side. The accumulation of pollutants was also clearly noticeable in these locations. A high concentration of H2S was recorded around the library building on the side of the car park. On the other hand, the air turbulence around the building dispersed the gas pollution, causing the concentration of H2S to drop on the leeward side. It was confirmed that in some analyzed areas the permissible concentration of H2S was exceeded.

scholarly journals A Climatology of Nocturnal Low-Level Jets at Cabauw

2009 ◽  
Vol 48 (8) ◽  
pp. 1627-1642 ◽  
Author(s):  
P. Baas ◽  
F. C. Bosveld ◽  
H. Klein Baltink ◽  
A. A. M. Holtslag
Keyword(s):  
Wind Speed ◽  
Ground Level ◽  
Geostrophic Wind ◽  
Stable Stratification ◽  
Radiative Cooling ◽  
Inertial Oscillation ◽  
Stable Boundary Layers ◽  
Above Ground Level ◽  
Low Level ◽  
Low Level Jets

Abstract A climatology of nocturnal low-level jets (LLJs) is presented for the topographically flat measurement site at Cabauw, the Netherlands. LLJ characteristics are derived from a 7-yr half-hourly database of wind speed profiles, obtained from the 200-m mast and a wind profiler. Many LLJs at Cabauw originate from an inertial oscillation, which develops after sunset in a layer decoupled from the surface by stable stratification. The data are classified to different types of stable boundary layers by using the geostrophic wind speed and the isothermal net radiative cooling as classification parameters. For each of these classes, LLJ characteristics like frequency of occurrence, height above ground level, and the turning of the wind vector across the boundary layer are determined. It is found that LLJs occur in about 20% of the nights, are typically situated at 140–260 m above ground level, and have a speed of 6–10 m s−1. Development of a substantial LLJ is most likely to occur for moderate geostrophic forcing and a high radiative cooling. A comparison with the 40-yr ECMWF Re-Analysis (ERA-40) is added to illustrate how the results can be used to evaluate the performance of atmospheric models.

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