Comparison of the centroid method and four standard formulas for estimating log volumes

Centroid Samling was tested on 21 logs of Ash (Fraxinus angustifolia subsp. oxycarpa), 38 logs of Spruce (Picea orientalis (L.) Link.), and 33 logs of Beech (Fagus orientalis Lipsky.) all of which were measured in detail. | Tr. J. of Agriculture and Forestry 23 (1999) 597-602 © TÜBİTAK Comparison of the Centroid Method and Four Standard Formulas for Estimating Log Volumes Hakkı YAVUZ Karadeniz Teknik Üniversitesi, Orman Fakültesi, Orman Mühendisliği Bölümü, Trabzon-TURKEY Received: Abstract: Centroid Samling was tested on 21 logs of Ash (Fraxinus angustifolia subsp. oxycarpa), 38 logs of Spruce (Picea orientalis (L.) Link.), and 33 logs of Beech (Fagus orientalis Lipsky.) all of which were measured in detail. The wolume of each log was estimated using Huber’s, Smalian’s, Newton, Riecke’s, Hosfeld’s formulas and Centroid Sampling. These estimates were compared with “true” volume of each log which was determined by aggregating the volumes of measured short sections (1 m.) using Smalian’s formula. The mean error of the Centroid estimate of the log volumes was not significant for Fraxinus angustifolia subsp. oxycarpa, Picea orientalis (L.) Link., and Fagus orientalis Lipsky. and was less than those derived from Huber’s, Smalian’s, Newton-Riecke’s, and Hosfeld’s formulas. When three species were combined, the Centroid estimate was clearly more accurate, and its mean error was not significant at probability level. Tomruk Hacimlerinin Hesaplanmasında Centroid Metod ve Dört Standart Formülün Kıyaslanması Özet: Ayrıntılı bir şekilde ölçülen 21 Dışbudak (Fraxinus angustifolia subsp. oxycarpa), 38 Ladin (Picea orientalis (L.) Link.) ve 33 Kayın (Fagus orientalis Lipsky.) tomruğuna bağlı olarak Centroid Sampling yöntemi test edilmiştir. Her bir tomruğa ilişkin hacimler; Huber, Smalian, Newton-Riecke, Hosfeld ve Centrod yöntemleriyle ayrı ayrı hesaplanarak tomrukların gerçek hacim değerleri ile kıyaslanmıştır. Tomrukların gerçek hacim değerleri ise Smalian yöntemi kullanılarak 1’er metrelik seksiyonların hacimleri toplamı olarak hesaplanmıştır. Centroid yöntemine göre tomruk hacimlerinin ortalama hatası her üç ağaç türü için de sıfırdan farksız bulunmuştur (p>) ve en düşük .