Comparative study of standard and modern methods for estimating tree bole volume of three species in Turkey

Tree bole volumes of 107 Cilicica fir (Abies cificica Carr.) trees, 96 Brutian pine (Pinus brutia Ten.) trees, and 67 Cedar of Lebanon (Cedrus libani A. Rich.) trees were estimated using current methodology (Huber's formula and local volume tables), modem techniques (the paracone method, the centroid method, importance sampling, control-variate sampling, singly and in combination) and Cascade Correlation Artificial Neural Network (CCANN) models. For validation purposes, the actual measured volumes were determined by aggregating the volumes of measured short sections (average I m) of the tree bole using Smalian's formula. The paracone method was superior to other methods tested in terms of both mean-square-bias (MSB%) of the percentage errors and tolerance intervals. The selected CCANN models gave unbiased results and were superior to all methods in terms of bias (%) expressed as the mean of the percentage errors.