scholarly journals Stem taper functions for white birch (Betula platyphylla) and costata birch (Betula costata) in the Xiaoxing’an Mountains, northeast China

2021 ◽  
Author(s):  
Amna Hussain ◽  
Muhammad Khurram Shahzad ◽  
Harold E Burkhart ◽  
Lichun Jiang
Keyword(s):  
Tree Species ◽  
Boreal Forests ◽  
Northeast China ◽  
Model Comparison ◽  
Betula Platyphylla ◽  
White Birch ◽  
Initial Attempt ◽  
Stem Taper ◽  
Xiaoxing’An Mountains ◽  
Taper Models

Abstract White birch (Betula platyphylla Sukaczev) and costata birch (Betula costata Trautv.) are valuable hardwood tree species growing in northeast China. Several taper studies have analysed birch species in the countries harbouring the boreal forests. However, this study presents an initial attempt to develop stem taper models using the fixed- and mixed-effects modelling for white birch and costata birch in Xiaoxing’an Mountains, northeast China. Ten commonly used taper models were evaluated by using 228 destructively sampled trees of both tree species comprising of 4582 diameter and height measurements. The performance of these models was tested in predicting diameter at any height, total volume and merchantable volume (10 and 20 cm top diameters). We incorporated a second-order continuous-time error structure to adjust the inherent autocorrelation in the data. The segmented model of Clark best predicted the diameter and total or merchantable volume when the upper stem diameter at 5.3 m was available. When diameter measurements at 5.3 m were not available, the models of Kozak and Max and Burkhart were superior to other models for white birch and costata birch, respectively. After model comparison, the best model of Clark was refitted as the NLME model.

scholarly journals A model form for stem taper and volume estimates of Asian white birch (Betula platyphylla): a major commercial tree species of Northeast China

2019 ◽  
pp. 274-286 ◽  
Author(s):  
Muhammad Khurram Shahzad ◽  
Amna Hussain ◽  
Lichun Jiang
Keyword(s):  
Northeast China ◽  
Individual Species ◽  
Betula Platyphylla ◽  
White Birch ◽  
Box Plots ◽  
Stem Taper ◽  
Overall Evaluation ◽  
Betula Platyphylla Suk ◽  
Volume Estimates ◽  
Volume Equations

Stem taper functions are valuable tools for the study of stem profile and predict volume estimates. Such functions have long been analyzed for different birch species in the world. However, Asian white birch (Betula platyphylla Suk.) has not yet been investigated as an individual species in China or abroad. This study presents stem taper and volume equations for B. platyphylla in Northeast China. Eight commonly used taper functions were fit to the data of 615 destructively sampled trees from two regions of Northeast China. A second-order continuous autoregressive error structure was incorporated to address the autocorrelation in the data and to achieve the valid parameter estimation. The condition number was used to detect the multicollinearity in the models. The taper functions were compared in terms of overall evaluation statistics and by examining the box plots of diameter and volume residuals against relative heights and diameter classes. The equations of A. Kozak (2004, For. Chron. 80(4): 507–515; model 2), Z. Fang et al. (2000, For. Sci. 46(1): 1–12), and H. Bi (2000, For. Sci. 46(3): 397–409) were the leading models for diameter and volume estimates. Overall, the equation of Z. Fang et al. (2000, For. Sci. 46(1): 1–12) exhibited the best results for estimating diameter and total and merchantable volumes in terms of statistical performance and lower multicollinearity.

scholarly journals Stem taper functions for Betula platyphylla in the Daxing’an Mountains, northeast China

2020 ◽  
Author(s):  
Muhammad Khurram Shahzad ◽  
Amna Hussain ◽  
Harold E. Burkhart ◽  
Fengri Li ◽  
Lichun Jiang
Keyword(s):  
Northeast China ◽  
Betula Platyphylla ◽  
Stem Taper ◽  
Daxing’An Mountains

Comparison of stem taper models for the four tropical tree species in Mount Makiling, Philippines

2016 ◽  
Vol 13 (3) ◽  
pp. 536-545 ◽  
Author(s):  
Roscinto Ian C. Lumbres ◽  
Azyleah C. Abino ◽  
Nelson M. Pampolina ◽  
Feliciano G. Calora ◽  
Young Jin Lee
Keyword(s):  
Tree Species ◽  
Tropical Tree ◽  
Tropical Tree Species ◽  
Stem Taper ◽  
Taper Models

scholarly journals Stochastic Models to Qualify Stem Tapers

Algorithms ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 94
Author(s):  
Edmundas Petrauskas ◽  
Petras Rupšys ◽  
Martynas Narmontas ◽  
Marius Aleinikovas ◽  
Lina Beniušienė ◽  
...  
Keyword(s):  
Tree Species ◽  
Boreal Forests ◽  
Goodness Of Fit ◽  
Diffusion Processes ◽  
Gompertz Model ◽  
Stem Volume ◽  
Black Alder ◽  
Longitudinal Measurements ◽  
Performance Statistics ◽  
Taper Models

This study examines the performance of 11 tree taper models to predict the diameter of bark at any given height and the total stem volume of eight dominant tree species in the boreal forests of Lithuania. Here, we develop eight new models using stochastic differential equations (SDEs). The symmetrical Vasicek model and asymmetrical Gompertz model are used to describe tree taper evolution, as well as geometric-type diffusion processes. These models are compared with those traditionally used for four tree taper models by using performance statistics and residual analysis. The observed dataset consists of longitudinal measurements of 3703 trees, representing the eight dominant tree species in Lithuania (pine, spruce, oak, ash, birch, black alder, white alder, and aspen). Overall, the best goodness of fit statistics of diameter predictions produced the SDE taper models. All results have been implemented in the Maple computer algebra system using the “Statistics” and “VectorCalculus” packages.

Some toxic effects of fenitrothion on seed germination and early seedling growth of jack pine, spruce, and birches

1978 ◽  
Vol 8 (2) ◽  
pp. 243-246 ◽  
Author(s):  
Pearl Weinberger ◽  
L. Pomber ◽  
R. Prasad
Keyword(s):  
Seed Germination ◽  
Seedling Growth ◽  
Tree Species ◽  
Boreal Forests ◽  
Jack Pine ◽  
White Birch ◽  
Early Seedling Growth ◽  
Percent Germination ◽  
Early Seedling ◽  
Tree Seeds

The seeds of four tree species (two conifers and two angiosperms) indigenous to the spruce boreal forests of Canada were exposed to 10 ppm (field concentration) and 1000 ppm fenitrothion during stratification and (or) early seedling growth. Pinusbanksiana Lamb. (jack pine) seeds exposed to 1000 ppm fenitrothion germinated more rapidly at first (0–10 days) but later were indistinguishable from untreated or 10 ppm fenitrothion treated seeds. The speed and percent germination of Piceaglauca (Moench) Voss (white spruce) seeds were unaffected by either fenitrothion treatment. After 5 months growth the conifer seedlings derived from fenitrothion treated seeds were comparable to untreated seedlings. The (angiosperm tree) seeds of Betulaalleghaniensis Britton and Betulapaperifera Marsh, (yellow and white birch) showed reduced germination following exposure to 10 ppm fenitrothion and marked toxicological damage when exposed to 1000 ppm fenitrothion.

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