Modeling diameter distribution of natural oriental beech stands in the Almus region using the Weibull distribution

Onur Alkan; Ramazan Ozçelik; Şerife Kalkanlı

Makale detayları

Modeling diameter distribution of natural oriental beech stands in the Almus region using the Weibull distribution

Yazarlar:

Onur Alkan | Ramazan Ozçelik | Şerife Kalkanlı

Yayıncı:

Isparta University of Applied Sciences

Ana Başlıklar:

Orman Biyometrisi

Dergi:

Turkish Journal of Forestry Vol.24 Issue 3, pp.197-207

Belge Tipi:

Makale

Yayın Tarihi:

9/2023

Belge Dili:

Türkçe

Document ID (Org No.):

2001300111

pISSN:

2149-3898

Anahtar kelimeler:

Özet:

 Oriental beech Fagus orientalis Lipsky ranks second among hardwood tree species in terms of area in Türkiye and ranks first in industrial wood production with a rate of 15. In this context, reliable and accurate information on the status, growth and development characteristics of these forests is needed to create future planning and strategies for both the protection and sustainable management of Oriental beech forests. The information to be obtained with the help of diameter distribution models, which is one of the most important components of growth and yield models, can reveal possible stand structures that will emerge because of different silvicultural interventions to be applied to the stands. The Weibull distribution is used extensively by many researchers for the modeling of diameter distributions because it has a more flexible structure than other models and has a cumulative distribution function in closed form. In this study, diameter distribution models were developed for natural, even-aged, and pure oriental beech stands in the Tokat-Almus region using the Weibull distribution. Two different approaches, namely the Seemingly Unrelated Regression SUR and Modified Cumulative Distribution Function Regression MCDF to estimate the coefficients of the regression equation used for the estimation of the parameters of the Weibull distribution function. Four different parameter estimation methods, namely parameter estimation method, moment- and percentile-based parameter recovery methods, and hybrid method were used. According to the results, it was determined that the models developed with the MCDF approach were more successful than the SUR approach. In terms of parameter estimation methods, it was determined that the moment-based method in the models developed with the SUR approach, and the hybrid method in terms of MCDF gave the most successful results. The poorest performer was the parameter estimation method developed within the SUR approach.

 Oriental beech Fagus orientalis Lipsky ranks second among hardwood tree species in terms of area in Türkiye and ranks first in industrial wood production with a rate of 15. In this context, reliable and accurate information on the status, growth and development characteristics of these forests is needed to create future planning and strategies for both the protection and sustainable management of Oriental beech forests. The information to be obtained with the help of diameter distribution models, which is one of the most important components of growth and yield models, can reveal possible stand structures that will emerge because of different silvicultural interventions to be applied to the stands. The Weibull distribution is used extensively by many researchers for the modeling of diameter distributions because it has a more flexible structure than other models and has a cumulative distribution function in closed form. In this study, diameter distribution models were developed for natural, even-aged, and pure oriental beech stands in the Tokat-Almus region using the Weibull distribution. Two different approaches, namely the Seemingly Unrelated Regression SUR and Modified Cumulative Distribution Function Regression MCDF to estimate the coefficients of the regression equation used for the estimation of the parameters of the Weibull distribution function. Four different parameter estimation methods, namely parameter estimation method, moment- and percentile-based parameter recovery methods, and hybrid method were used. According to the results, it was determined that the models developed with the MCDF approach were more successful than the SUR approach. In terms of parameter estimation methods, it was determined that the moment-based method in the models developed with the SUR approach, and the hybrid method in terms of MCDF gave the most successful results. The poorest performer was the parameter estimation method developed within the SUR approach.

 Oriental beech Fagus orientalis Lipsky ranks second among hardwood tree species in terms of area in Türkiye and ranks first in industrial wood production with a rate of 15. In this context, reliable and accurate information on the status, growth and development characteristics of these forests is needed to create future planning and strategies for both the protection and sustainable management of Oriental beech forests. The information to be obtained with the help of diameter distribution models, which is one of the most important components of growth and yield models, can reveal possible stand structures that will emerge because of different silvicultural interventions to be applied to the stands. The Weibull distribution is used extensively by many researchers for the modeling of diameter distributions because it has a more flexible structure than other models and has a cumulative distribution function in closed form. In this study, diameter distribution models were developed for natural, even-aged, and pure oriental beech stands in the Tokat-Almus region using the Weibull distribution. Two different approaches, namely the Seemingly Unrelated Regression SUR and Modified Cumulative Distribution Function Regression MCDF to estimate the coefficients of the regression equation used for the estimation of the parameters of the Weibull distribution function. Four different parameter estimation methods, namely parameter estimation method, moment- and percentile-based parameter recovery methods, and hybrid method were used. According to the results, it was determined that the models developed with the MCDF approach were more successful than the SUR approach. In terms of parameter estimation methods, it was determined that the moment-based method in the models developed with the SUR approach, and the hybrid method in terms of MCDF gave the most successful results. The poorest performer was the parameter estimation method developed within the SUR approach.

 Doğu Kayını Fagus orientalis Lipsky, Türkiyede alan bakımından yapraklı ağaç türleri içerisinde ikinci sırada, endüstriyel odun üretiminde ise 15lik payı ile ilk sırada yer almaktadır. Bu çerçevede, Doğu Kayını ormanlarının bir taraftan korunması, diğer taraftan da sürdürülebilir yönetimi amacıyla, geleceğe dönük planlama ve stratejilerin oluşturulması için bu ormanların mevcut durumuna, büyüme ve gelişme özelliklerine ilişkin güvenilir ve nitelikli bilgilere ihtiyaç duyulmaktadır. Büyüme ve hasılat modellerinin en önemli bileşenlerinden biri olan çap dağılım modelleridir. Bu modeller yardımıyla, meşcerelere uygulanacak farklı silvikültürel müdahaleler sonucunda ortaya çıkacak olası meşcere yapıları hakkında önemli bilgiler elde edilebilmektedir. Weibull dağılımı, diğer modellere göre daha esnek bir yapıya sahip olması ve kapalı formda eklemeli dağılım fonksiyonuna sahip olması nedeniyle pek çok araştırmacı tarafından çap dağılımlarının modellenmesi amacıyla yoğun bir şekilde kullanılmaktadır. Bu çalışmada, Weibull dağılımı kullanılarak, Tokat-Almus yöresi doğal, aynı-yaşlı ve saf Doğu Kayını meşcereleri için çap dağılım modelleri geliştirilmiştir. Weibull dağılım fonksiyonun parametrelerinin tahmini için kullanılan regresyon denkleminin katsayılarını tahmin etmek amacıyla, Görünürde Uyumsuz Regresyon Denklemi SUR ve Değiştirilmiş Kümülatif Dağılım Fonksiyon Regresyonu MCDF olmak üzere iki farklı yaklaşım ile parametre tahmin yöntemi, moment ve yüzdelik temelli parametre çözümleme yöntemleri ve hibrit yöntem olmak üzere dört farklı yöntem kullanılmıştır. Çalışma kapsamında MCDF yaklaşımı ile geliştirilen modellerin SUR yaklaşımına göre daha başarılı olduğu belirlenmiştir. Parametre tahmin yöntemleri itibariyle SUR yaklaşımı ile geliştirilen modellerde moment temelli yöntemin, MCDF itibariyle ise hibrit yöntemin en başarılı sonuçları verdiği belirlenmiştir. Tahmin başarısı bakımından en başarısız olan yöntem ise SUR yaklaşımı kapsamında geliştirilen parametre tahmin yöntemi olarak belirlenmiştir.

Makale detayları

Modeling diameter distribution of natural oriental beech stands in the Almus region using the Weibull distribution

Yazarlar:

Onur Alkan | Ramazan Ozçelik | Şerife Kalkanlı

Yayıncı:

Isparta University of Applied Sciences

Ana Başlıklar:

Orman Biyometrisi

Dergi:

Turkish Journal of Forestry Vol.24 Issue 3, pp.197-207

Belge Tipi:

Makale

Yayın Tarihi:

9/2023

Belge Dili:

Türkçe

Document ID (Org No.):

2001300111

pISSN:

2149-3898

Diameter distribution models

Weibull distribution

Oriental beechÇap dağılım modelleri

Weibull dağılımı

Doğu kayını

Sayı

Makale detayları

Modeling diameter distribution of natural oriental beech stands in the Almus region using the Weibull distribution

Yazarlar: Onur Alkan | Ramazan Ozçelik | Şerife Kalkanlı

Yayıncı: Isparta University of Applied Sciences

Ana Başlıklar: Orman Biyometrisi

Dergi: Turkish Journal of Forestry Vol.24 Issue 3, pp.197-207

Belge Tipi: Makale

Yayın Tarihi: 9/2023

Belge Dili: Türkçe

Document ID (Org No.): 2001300111

pISSN: 2149-3898

Diameter distribution models

Weibull distribution

Oriental beechÇap dağılım modelleri

Weibull dağılımı

Doğu kayını

Sayı

Yazarlar:

Onur Alkan | Ramazan Ozçelik | Şerife Kalkanlı

Yayıncı:

Isparta University of Applied Sciences

Ana Başlıklar:

Orman Biyometrisi

Dergi:

Turkish Journal of Forestry Vol.24 Issue 3, pp.197-207

Belge Tipi:

Makale

Yayın Tarihi:

9/2023

Belge Dili:

Türkçe

Document ID (Org No.):

2001300111

pISSN:

2149-3898