Effects of adding crown variables in stem taper and volume predictions for black pine

Ramazan ÖZÇELİK; Cafer BAL

Makale detayları

Effects of adding crown variables in stem taper and volume predictions for black pine

Yazarlar:

Ramazan ÖZÇELİK | Cafer BAL

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Agriculture and Forestry 2013 Vol.37 Issue 2, pp.231-242

Belge Tipi:

Makale

Yayın Tarihi:

1/2013

Belge Dili:

Türkçe

Document ID (Org No.):

2000807732

Sıklık:

İki Aylık

eISSN:

1303-6173

pISSN:

1300-011X

Anahtar kelimeler:

Özet:

 

Crown characteristics are an important component of growth and yield models. The stem form of a tree depends to a large extent on the tree crown dimensions. However, there is no unified agreement on whether crown variables (crown ratio and crown length) should be incorporated into taper models for accurate predictions of diameter and volume. The purpose of this study was to investigate the level of improvement that the incorporation of crown variables into taper equations for black pine (Pinus nigra J.F.Arnold subsp. pallasiana (Lamb.) Holmboe) gives to diameter and stem volume predictions. Linear and nonlinear crown variable functions were incorporated into a compatible volume and taper equation to evaluate their effect in model prediction accuracy. The inclusion of crown variables provided significantly different parameter estimates but only resulted in a modest reduction of fitting statistics for both diameter and volume with lower average bias and lower mean squared errors for all modified models, although the improvement in stem volume prediction was minimal. Based on the results, the improvement obtained by the inclusion of crown variables is not enough to justify the additional costs in measuring crown variables of standing trees for volume estimation.

 

Crown characteristics are an important component of growth and yield models. The stem form of a tree depends to a large extent on the tree crown dimensions. However, there is no unified agreement on whether crown variables (crown ratio and crown length) should be incorporated into taper models for accurate predictions of diameter and volume. The purpose of this study was to investigate the level of improvement that the incorporation of crown variables into taper equations for black pine (Pinus nigra J.F.Arnold subsp. pallasiana (Lamb.) Holmboe) gives to diameter and stem volume predictions. Linear and nonlinear crown variable functions were incorporated into a compatible volume and taper equation to evaluate their effect in model prediction accuracy. The inclusion of crown variables provided significantly different parameter estimates but only resulted in a modest reduction of fitting statistics for both diameter and volume with lower average bias and lower mean squared errors for all modified models, although the improvement in stem volume prediction was minimal. Based on the results, the improvement obtained by the inclusion of crown variables is not enough to justify the additional costs in measuring crown variables of standing trees for volume estimation.

Makale detayları

Effects of adding crown variables in stem taper and volume predictions for black pine

Yazarlar:

Ramazan ÖZÇELİK | Cafer BAL

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Agriculture and Forestry 2013 Vol.37 Issue 2, pp.231-242

Belge Tipi:

Makale

Yayın Tarihi:

1/2013

Belge Dili:

Türkçe

Document ID (Org No.):

2000807732

Sıklık:

İki Aylık

eISSN:

1303-6173

pISSN:

1300-011X

Key words: Crown ratio

crown length

diameter

segmented taper model

Sayı

Makale detayları

Effects of adding crown variables in stem taper and volume predictions for black pine

Yazarlar: Ramazan ÖZÇELİK | Cafer BAL

Yayıncı: TUBITAK

Dergi: Turkish Journal of Agriculture and Forestry 2013 Vol.37 Issue 2, pp.231-242

Belge Tipi: Makale

Yayın Tarihi: 1/2013

Belge Dili: Türkçe

Document ID (Org No.): 2000807732

Sıklık: İki Aylık

eISSN: 1303-6173

pISSN: 1300-011X

Key words: Crown ratio

crown length

diameter

segmented taper model

Sayı

Yazarlar:

Ramazan ÖZÇELİK | Cafer BAL

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Agriculture and Forestry 2013 Vol.37 Issue 2, pp.231-242

Belge Tipi:

Makale

Yayın Tarihi:

1/2013

Belge Dili:

Türkçe

Document ID (Org No.):

2000807732

Sıklık:

İki Aylık

eISSN:

1303-6173

pISSN:

1300-011X