Predicting past and future diameter growth for trees in the northeastern United States

2006 ◽  
Vol 36 (6) ◽  
pp. 1551-1562 ◽  
Author(s):  
James A Westfall
Keyword(s):  
United States ◽  
Growth Models ◽  
Error Function ◽  
Forest Growth ◽  
Diameter Growth ◽  
Northeastern United States ◽  
Mixed Effects Modeling ◽  
Acquisition Costs ◽  
Species Groups ◽  
Diameter Growth Models

Tree diameter growth models are widely used in forestry applications, often to predict tree size at a future point in time. Also, there are instances where projections of past diameters are needed. A relative diameter growth model was developed to allow prediction of both future and past growth rates. Coefficients were estimated for 15 species groups that cover most tree species in the northeastern United States. Application of the model to independent data generally showed slight underprediction of growth, although the bias was negligible. Correlated observations were accounted for via a mixed-effects modeling approach, and an error function was specified to address heterogeneous variance. The models use a minimum amount of field-collected data, thus keeping data acquisition costs low and facilitating use in many forest growth applications.

scholarly journals Evaluation of Individual Distance-Independent Diameter Growth Models for Japanese Cedar (Cryptomeria japonica) Trees under Multiple Thinning Treatments

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 344 ◽  
Author(s):  
Keiko Fukumoto ◽  
Tomohiro Nishizono ◽  
Fumiaki Kitahara ◽  
Kazuo Hosoda
Keyword(s):  
Forest Management ◽  
Tree Growth ◽  
Cryptomeria Japonica ◽  
Growth Models ◽  
Japanese Cedar ◽  
Diameter Growth ◽  
Model Accuracy ◽  
Thinning Intensity ◽  
Diameter Growth Models

Understanding the tree growth process is essential for sustainable forest management. Future yields are affected by various forest management regimes such as thinning; therefore, accurate predictions of tree growth are needed under various thinning intensities. This study compared the accuracy of individual-level distance-independent diameter growth models constructed for different thinning intensities (thinning intensity-dependent multiple models: TDM model) against the model designed to include all thinning intensities (thinning intensity-independent single model: TIS model) to understand how model accuracy is affected by thinning intensity. We used long-term permanent plot data of Japanese cedar (Cryptomeria japonica) stands in Japan, which was gathered from four plots where thinning was conducted at different thinning intensities: (1) intensive (41% and 38% of trees removed at 25 and 37 years old, respectively), (2) moderate (38% and 34%), (3) light (32% and 34%), and (4) no thinning. First, we specified high interpretability distance-independent competition indices, and we compared the model accuracy both in TDM and TIS models. The results show that the relative spacing index was the best competition index both in TDM and TIS models across all thinning intensities, and the differences in the RMSE (Root mean square error) and rRMSE (relative RMSE) in both TDM and TIS models were 0.001–0.01 cm and 0.2–2%, respectively. In the TIS model, rRMSE varied with thinning intensity; the rRMSE was the lowest for moderate thinning intensity (45.8%) and the highest for no thinning (59.4%). In addition, bias values were negative for the TIS model for all thinning intensities. These results suggest that the TIS model could express diameter growth regardless of thinning intensities. However, the rRMSE had varied with thinning intensity and bias had negative values in the TIS model. Therefore, more model improvements are required for accurate predictions of long-term growth of actual Japanese cedar stands.

scholarly journals Proposals for Nothofagus antarctica diameter growth estimation: simple vs. global models

2014 ◽  
Vol 60 (No. 8) ◽  
pp. 307-317 ◽  
Author(s):  
H. Ivancich ◽  
G.J. Martínez Pastur ◽  
M.V. Lencinas ◽  
J.M. Cellini ◽  
P.L. Peri
Keyword(s):  
Tree Growth ◽  
Growth Models ◽  
Site Quality ◽  
Diameter Growth ◽  
Wide Range ◽  
Nothofagus Antarctica ◽  
Simple Growth ◽  
Simple Equations ◽  
Diameter Growth Models ◽  
Stand Conditions

Tree growth is one of the main variables needed for forest management planning. The use of simple models containing traditional equations to describe tree growth is common. However, equations that incorporate different factors (e.g. site quality of the stands, crown classes of the trees, silvicultural treatments) may improve their accuracy in a wide range of stand conditions. The aim of this work was to compare the accuracy of tree diameter growth models using (i) a family of simple equations adjusted by stand site quality and crown class of trees, and (ii) <br /> a unique global equation including stand and individual tree variables. Samplings were conducted in 136 natural even-aged Nothofagus antarctica (Forster f.) Oersted stands in Southern Patagonia (Argentina) covering age (20&ndash;200 years), <br /> crown class and site quality gradients. The following diameter growth models were fitted: 16 simple equations using two independent variables (age and one equation for each stand site quality or crown class) based on Richards model, plus a unique global equation using three independent variables (age, stand site quality and crown class). Simple equations showed higher variability in their accuracy, explained between 54% and 92% of the data variation. The global model presented similar accuracy like the better equations of the simple growth models. The unification of the simple growth models into a unique global equation did not greatly improve the accuracy of estimations, but positively influenced the biological response of the model. Another advantage of the global equation is the simple use under a wide range of natural stand conditions. The proposed global model allows to explain the tree growth of N. antarctica trees along the natural studied gradients. &nbsp; &nbsp;

scholarly journals Individual-Tree Diameter Growth Models for Mixed Nothofagus Second Growth Forests in Southern Chile

Forests ◽  
2017 ◽  
Vol 8 (12) ◽  
pp. 506 ◽  
Author(s):  
Paulo Moreno ◽  
Sebastian Palmas ◽  
Francisco Escobedo ◽  
Wendell Cropper ◽  
Salvador Gezan
Keyword(s):  
Growth Models ◽  
Diameter Growth ◽  
Southern Chile ◽  
Individual Tree ◽  
Tree Diameter ◽  
Second Growth ◽  
Diameter Growth Models

scholarly journals Development of Diameter Growth Models by Thinning Intensity of Planted Quercus glauca Thunb. Stands

2021 ◽  
Vol 24 (6) ◽  
pp. 629-638
Author(s):  
Su Young Jung ◽  
Kwang Soo Lee ◽  
Hyun Soo Kim
Keyword(s):  
Mean Squared Error ◽  
Growth Models ◽  
Diameter Growth ◽  
Least Squares Regression ◽  
Permanent Sample Plots ◽  
Thinning Intensity ◽  
Squared Error ◽  
Quercus Glauca ◽  
The Mean ◽  
Diameter Growth Models

Background and objective: This study was conducted to develop diameter growth models for thinned Quercus glauca Thunb. (QGT) stands to inform production goals for treatment and provide the information necessary for the systematic management of this stands.Methods: This study was conducted on QGT stands, of which initial thinning was completed in 2013 to develop a treatment system. To analyze the tree growth and trait response for each thinning treatment, forestry surveys were conducted in 2014 and 2021, and a one-way analysis of variance (ANOVA) was executed. In addition, non-linear least squares regression of the PROC NLIN procedure was used to develop an optimal diameter growth model.Results: Based on growth and trait analyses, the height and height-to-diameter (H/D) ratio were not different according to treatment plot (p > .05). For the diameter of basal height (DBH), the heavy thinning (HT) treatment plot was significantly larger than the control plot (p < .05). As a result of the development of diameter growth models by treatment plot, the mean squared error (MSE) of the Gompertz polymorphic equation (control: 2.2381, light thinning: 0.8478, and heavy thinning: 0.8679) was the lowest in all treatment plots, and the Shapiro-Wilk statistic was found to follow a normal distribution (p > .95), so it was selected as an equation fit for the diameter growth model.Conclusion: The findings of this study provide basic data for the systematic management of Quercus glauca Thunb. stands. It is necessary to construct permanent sample plots (PSP) that consider stand status, location conditions, and climatic environments.

SYSTEMATICS OF THE NEARCTIC SPECIES OF METALLIC-GREEN COLEOPHORA (LEPIDOPTERA: COLEOPHORIDAE)

1993 ◽  
Vol 125 (3) ◽  
pp. 549-618 ◽  
Author(s):  
Jean-François Landry ◽  
Barry Wright
Keyword(s):  
United States ◽  
Life History ◽  
Phylogenetic Relationships ◽  
Host Plants ◽  
Species Distributions ◽  
Northeastern United States ◽  
Species Groups ◽  
Nearctic Region ◽  
Eleven Species

AbstractEleven species of metallic-green Coleophora are recognized in the Nearctic Region, including three that are new: C. ladonia Landry and Wright from Florida, C. ramitella Landry and Wright from the northeastern United States, and C. timarella Landry and Wright from Arizona. Three species are introduced from Europe: C. deauratella Lienig and Zeller, C. mayrella (Hübner), and C. trifolii (Curtis); these are pests of clover seeds. Adults are keyed, described, and illustrated, and the species distributions mapped. Host plants are known for eight of the species, for which larval cases are also illustrated and their life history presented. Nearctic species of metallic-green Coleophora represent a miscellany of unrelated groups, here treated together for convenience. Tentative definitions of informal species groups are provided and phylogenetic relationships of the species are discussed.

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.

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