Stand volume estimation from tree counts in the context of vertical line sampling

1990 ◽  
Vol 20 (3) ◽  
pp. 274-279 ◽  
Author(s):  
Thomas B. Lynch
Keyword(s):  
Volume Estimation ◽  
Vertical Line ◽  
Individual Tree ◽  
Stand Volume ◽  
Variable Volume ◽  
Sample Tree ◽  
Line Sampling ◽  
Constant Form ◽  
Volume Equation ◽  
Line Sample

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.

Variance reduction in Ueno's method and cylinder sampling for forest volume estimation

1995 ◽  
Vol 25 (11) ◽  
pp. 1783-1794 ◽  
Author(s):  
Thomas B. Lynch
Keyword(s):  
Computer Simulation ◽  
Variance Reduction ◽  
Volume Estimation ◽  
Critical Height ◽  
Volume Estimate ◽  
Individual Tree ◽  
Stand Volume ◽  
Reduction Techniques ◽  
Antithetic Variates ◽  
Volume Equation

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.

Use of a tree volume equation based on two lower-stem diameters to estimate forest volume from sample tree counts

1995 ◽  
Vol 25 (6) ◽  
pp. 871-877 ◽  
Author(s):  
Thomas B. Lynch
Keyword(s):  
Linear Equations ◽  
Stem Diameter ◽  
Linear Functions ◽  
Individual Tree ◽  
Point Sampling ◽  
Sample Tree ◽  
Fixed Radius ◽  
Volume Equation ◽  
The Individual ◽  
Lower Stem

A recently developed method of individual-tree volume prediction uses measurements of two lower-stem diameters, rather than the more traditional DBH and height measurements, to estimate stemwood. One form of the equation is linear with respect to volume between the two diameter measurements, as computed by Smalian's formula, and can be algebraically rearranged into the sum of two equations, one linear with respect to the square of the topmost lower-stem diameter, the other linear with respect to the square of the bottom lower-stem diameter. These two equations have the same form as local volume equations that are linear functions of the square of diameter. Because of this, a variation of horizontal point sampling can be used to select trees with probability exactly proportional to each of the equations. Forest volumes can be estimated from counts of trees obtained by comparing the point sampling gauge angle with individual tree diameters at the lower-stem diameter measurement points used by the individual-tree volume equation. To account for the negative intercept term in the linear equations, trees within a small fixed-radius plot are not included in the counts.

An Equation for Estimating Total Volume of Both Stands and Single Trees of Black Spruce

1983 ◽  
Vol 59 (1) ◽  
pp. 26-29 ◽  
Author(s):  
F. Evert
Keyword(s):  
Picea Mariana ◽  
Black Spruce ◽  
Direct Reference ◽  
Individual Tree ◽  
Stand Volume ◽  
Volume Equation ◽  
The Individual ◽  
Individual Trees

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.

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 Height Extraction and Stand Volume Estimation Based on Fusion Airborne LiDAR Data and Terrestrial Measurements for a Norway Spruce [Picea abies (L.) Karst.] Test Site in Romania

2016 ◽  
Vol 44 (1) ◽  
pp. 313-323 ◽  
Author(s):  
Bogdan APOSTOL ◽  
Adrian LORENT ◽  
Marius PETRILA ◽  
Vladimir GANCZ ◽  
Ovidiu BADEA
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Volume Estimation ◽  
Airborne Lidar ◽  
Stem Volume ◽  
Lidar Data ◽  
Individual Tree ◽  
Stand Volume ◽  
Empirical Modelling ◽  
The Individual

The objective of this study was to analyze the efficiency of individual tree identification and stand volume estimation from LiDAR data. The study was located in Norway spruce [Picea abies (L.) Karst.] stands in southwestern Romania and linked airborne laser scanning (ALS) with terrestrial measurements through empirical modelling. The proposed method uses the Canopy Maxima algorithm for individual tree detection together with biometric field measurements and individual trees positioning. Field data was collected using Field-Map real-time GIS-laser equipment, a high-accuracy GNSS receiver and a Vertex IV ultrasound inclinometer. ALS data were collected using a Riegl LMS-Q560 instrument and processed using LP360 and Fusion software to extract digital terrain, surface and canopy height models. For the estimation of tree heights, number of trees and tree crown widths from the ALS data, the Canopy Maxima algorithm was used together with local regression equations relating field-measured tree heights and crown widths at each plot. When compared to LiDAR detected trees, about 40-61% of the field-measured trees were correctly identified. Such trees represented, in general, predominant, dominant and co-dominant trees from the upper canopy. However, it should be noted that the volume of the correctly identified trees represented 60-78% of the total plot volume. The estimation of stand volume using the LiDAR data was achieved by empirical modelling, taking into account the individual tree heights (as identified from the ALS data) and the corresponding ground reference stem volume. The root mean square error (RMSE) between the individual tree heights measured in the field and the corresponding heights identified in the ALS data was 1.7-2.2 meters. Comparing the ground reference estimated stem volume (at trees level) with the corresponding ALS estimated tree stem volume, an RMSE of 0.5-0.7 m3 was achieved. The RMSE was slightly lower when comparing the ground reference stem volume at plot level with the ALS-estimated one, taking into account both the identified and unidentified trees in the LiDAR data (0.4-0.6 m3).

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 Predicting Growing Stock Volume of Eucalyptus Plantations Using 3-D Point Clouds Derived from UAV Imagery and ALS Data

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 905 ◽  
Author(s):  
Guerra-Hernández ◽  
Cosenza ◽  
Cardil ◽  
Silva ◽  
Botequim ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Basal Area ◽  
Remote Sensing Data ◽  
Tree Height ◽  
Point Clouds ◽  
Volume Estimation ◽  
P Value ◽  
Test Statistic ◽  
Individual Tree ◽  
Significant Difference

Estimating forest inventory variables is important in monitoring forest resources and mitigating climate change. In this respect, forest managers require flexible, non-destructive methods for estimating volume and biomass. High-resolution and low-cost remote sensing data are increasingly available to measure three-dimensional (3D) canopy structure and to model forest structural attributes. The main objective of this study was to evaluate and compare the individual tree volume estimates derived from high-density point clouds obtained from airborne laser scanning (ALS) and digital aerial photogrammetry (DAP) in Eucalyptus spp. plantations. Object-based image analysis (OBIA) techniques were applied for individual tree crown (ITC) delineation. The ITC algorithm applied correctly detected and delineated 199 trees from ALS-derived data, while 192 trees were correctly identified using DAP-based point clouds acquired from Unmanned Aerial Vehicles (UAV), representing accuracy levels of respectively 62% and 60%. Addressing volume modelling, non-linear regression fit based on individual tree height and individual crown area derived from the ITC provided the following results: Model Efficiency (Mef) = 0.43 and 0.46, Root Mean Square Error (RMSE) = 0.030 m3 and 0.026 m3, rRMSE = 20.31% and 19.97%, and an approximately unbiased results (0.025 m3 and 0.0004 m3) using DAP and ALS-based estimations, respectively. No significant difference was found between the observed value (field data) and volume estimation from ALS and DAP (p-value from t-test statistic = 0.99 and 0.98, respectively). The proposed approaches could also be used to estimate basal area or biomass stocks in Eucalyptus spp. plantations.

scholarly journals Increased Individual Tree Growth Maintains Stand Volume Growth after B-Level Thinning and Crop-Tree Management in Mature Oak Stands

2019 ◽  
Vol 65 (6) ◽  
pp. 784-795
Author(s):  
Jeffrey S Ward ◽  
Jessica Wikle
Keyword(s):  
Tree Growth ◽  
Growth Response ◽  
Volume Growth ◽  
Diameter Growth ◽  
Red Oak ◽  
Individual Tree ◽  
Stand Volume ◽  
Tree Management ◽  
Individual Tree Growth ◽  
Partial Release

AbstractSix study areas were established in 80–125-year-old upland oak stands on average sites to compare stand and individual tree growth response following two active treatments (B-level thinning, crop tree) with an unmanaged control. Initial stocking of 104 percent was reduced to 62 percent and 60 percent on the B-level and crop-tree-management plots, respectively. Approximately 7,200 board feet per acre (International ¼) were harvested on the actively managed plots with upland oaks accounting for 81 percent of pre- and 86 percent of residual stand. Eleven-year diameter and volume growth of oak sawtimber trees was greater on actively managed plots. Growth response increased with degree of release and was maintained for the length of the study. Because of the increased individual tree growth of oaks in response to release, stand volume growth of oak sawtimber did not differ between treatments. In contrast to an 11-year decline of poletimber stocking on unmanaged plots, poletimber stocking increased on managed plots as diameter growth increased in response to partial release. This may increase difficulty of regenerating oak in the future. For those mature red oak stands where traditional regeneration prescriptions will not be implemented or will be delayed, commercial harvests can be conducted without compromising stand volume growth of oak.

Application of a geometrical volume equation to species with different bole forms

1986 ◽  
Vol 16 (2) ◽  
pp. 311-314 ◽  
Author(s):  
G. B. MacDonald ◽  
R. R. Forslund
Keyword(s):  
Diameter Measurement ◽  
Stem Analysis ◽  
Individual Tree ◽  
Breast Height ◽  
Centre Of Gravity ◽  
Variable Equation ◽  
Input Variables ◽  
Volume Equation ◽  
Volume Estimates ◽  
Geometrical Equation

Stem analysis of 20 Abiesbalsamea (L.) Mill., 68 Piceamariana (Mill.) B.S.P., 19 Piceaglauca (Moench) Voss, 31 Populustremuloides Michx., and 37 Betulapapyrifera Marsh. revealed form variation between species. A volume equation based on the paracone (a geometrical solid midway between a paraboloid and a cone) estimated individual tree volume within 10% of the true volume (at the 95% confidence level) for all species. The input variables required were total height and diameter at a relative height of 0.2 for Betulapapyrifera and 0.3 for the other four species. If breast-height diameter was used, the effect of form variation on the accuracy of volume prediction was more pronounced. In this case, the geometrical equation modified for each species according to the average centre of gravity provided more consistently accurate volume estimates than either the paracone equation or Honer's transformed variable equation. For all species, the diameter measurement position was more critical than the version of the geometrical equation selected.

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