scholarly journals Development of regional stem taper models for some important tree species of Turkey: Case study of Bucak

2019 ◽  
pp. 333-340 ◽  
Author(s):  
Ramazan Ozçelik ◽  
Onur ALKAN ◽  
HASAN ALKAN
Keyword(s):  
Tree Species ◽  
Stem Taper ◽  
Taper Models

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 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 O problema das espécies arbóreas exóticas comercializadas nos viveiros florestais: Estudo de caso no município de Juiz de Fora (MG) - The problem of exotic tree species marketed in forest nurseries: a case study in the municipality of Juiz de Fora (MG)

2015 ◽  
Vol 11 (1) ◽  
pp. 28 ◽  
Author(s):  
Norberto Emídio de Oliveira Neto ◽  
Cassiano Ribeiro da Fonseca ◽  
Fabrício Alvim Carvalho
Keyword(s):  
Tree Species ◽  
Persea Americana ◽  
Mata Atlântica ◽  
Syzygium Jambos ◽  
Morus Nigra ◽  
Exotic Tree ◽  
Mata Atlantica ◽  
Forest Nurseries

O comércio de mudas florestais para a recuperação de áreas degradadas e reflorestamento é crescente e demanda cada vez mais conhecimentos sobre práticas de manejo na produção de essências nativas, adequadas aos padrões ecológicos locais e à legislação ambiental vigente. Entretanto, a comercialização de mudas exóticas ainda é prática comum nos viveiros florestais, não existindo, para a microrregião de Juiz de Fora, MG, informações sobre os tipos de mudas comercializados nos viveiros florestais. Neste estudo foram levantadas as espécies florestais comercializadas em oito viveiros florestais no município de Juiz de Fora, MG, e que abastecem os projetos de reflorestamento na região. As espécies foram identificadas e categorizadas em nativas da Mata Atlântica ou exóticas. Foram encontradas ao todo 147 espécies. Destas, 64 (43,5% do total) foram exóticas, sendo encontradas, com grande frequência (>50%) entre os viveiros, englobando espécies frutíferas com perfil tipicamente comercial, como Psidium guaja), abacate (Persea americana), amora (Morus nigra) e cítricas – laranja, limão e tangerina (Citrus sp.). Também foram registradas algumas espécies consideradas de alto potencial invasor nas florestas Neotropicais, como o Jambo-rosa (Syzygium jambos), comercializada em metade dos viveiros analisados. A presente análise evidencia uma grande produção e comercialização de espécies exóticas de mudas florestais, utilizadas nos projetos de reflorestamento do município, o que não condiz com a legislação florestal vigente e ainda pode ser considerado como grande risco em potencial para invasão biológica.

scholarly journals Evolutionary history predicts the response of tree species to forest loss: A case study in peninsular Spain

PLoS ONE ◽  
2018 ◽  
Vol 13 (9) ◽  
pp. e0204365 ◽  
Author(s):  
Rafael Molina-Venegas ◽  
Sonia Llorente-Culebras ◽  
Paloma Ruiz-Benito ◽  
Miguel A. Rodríguez
Keyword(s):  
Tree Species ◽  
Evolutionary History ◽  
Forest Loss ◽  
Peninsular Spain

scholarly journals Models for Tree Taper Form: The Gompertz and Vasicek Diffusion Processes Framework

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 80 ◽  
Author(s):  
Martynas Narmontas ◽  
Petras Rupšys ◽  
Edmundas Petrauskas
Keyword(s):  
Goodness Of Fit ◽  
Diffusion Processes ◽  
Parameters Estimation ◽  
Data Set ◽  
Mixed Effect ◽  
Fit Statistics ◽  
Stem Taper ◽  
Longitudinal Measurements ◽  
High Level ◽  
Taper Models

In this work, we employ stochastic differential equations (SDEs) to model tree stem taper. SDE stem taper models have some theoretical advantages over the commonly employed regression-based stem taper modeling techniques, as SDE models have both simple analytic forms and a high level of accuracy. We perform fixed- and mixed-effect parameters estimation for the stem taper models by developing an approximated maximum likelihood procedure and using a data set of longitudinal measurements from 319 mountain pine trees. The symmetric Vasicek- and asymmetric Gompertz-type diffusion processes used adequately describe stem taper evolution. The proposed SDE stem taper models are compared to four regression stem taper equations and four volume equations. Overall, the best goodness-of-fit statistics are produced by the mixed-effect parameters SDEs stem taper models. All results are obtained in the Maple computer algebra system.

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