Mehmet Pak

A study on the use and modeling of geographical information system for combating forest crimes: an assessment of crimes in the eastern Mediterranean forests

This study focuses on the geo-statistical assessment of spatial estimation models in forest crimes. Used widely in the assessment of crime and crime-dependent variables, geographic information system (GIS) helps the detection of forest crimes in rural regions. In this study, forest crimes (forest encroachment, illegal use, illegal timber logging, etc.) are assessed holistically and modeling was performed with ten different independent variables in GIS environment. The research areas are three Forest Enterprise Chiefs (Baskonus, Cinarpinar, and Hartlap) affiliated to Kahramanmaras Forest Regional Directorate in Kahramanmaras. An estimation model was designed using ordinary least squares (OLS) and geographically weighted regression (GWR) methods, which are often used in spatial association. Three different models were proposed in order to increase the accuracy of the estimation model. The use of variables with a variance inflation factor (VIF) value of lower than 7.5 in Model I and lower than 4 in Model II and dependent variables with significant robust probability values in Model III are associated with forest crimes. Afterwards, the model with the lowest corrected Akaike Information Criterion (AICc), and the highest R2 value was selected as the comparison criterion. Consequently, Model III proved to be more accurate compared to other models. For Model III, while AICc was 328,491 and R2was 0.634 for OLS-3 model, AICc was 318,489 and R2 was 0.741 for GWR-3 model. In this respect, the uses of GIS for combating forest crimes provide different scenarios and tangible information that will help take political and strategic measures.

How stem defects affect the capability of optimum bucking method

In forest harvesting activities, computer-assisted optimum bucking method increases the economic value of harvested trees. The bucking decision highly depends on the log quality grades which mainly vary with the surface characteristics such as stem defects and form of the stems. In this study, the effects of stem defects on optimum bucking method was investigated by comparing bucking applications which were conducted during the logging operations in two different Brutian Pine (Pinus brutia Ten) stands. In the applications, the first stand contained the stems with relatively more stem defects than that of the stems in the second stand. The average number of defects per log for sample trees in the first and the second stand was recorded as 3.64 and 2.70, respectively. The results indicated that optimum bucking method increased the average economic value of harvested trees by 15.45% and 8.26 % in the stands, respectively. Therefore, the computer-assisted optimum bucking method potentially provides better results than that of traditional bucking method especially for the harvested trees with more stem defects. Anahtar kelimeler: Tree surface properties, log quality grades, cross-cutting, Brutian pine Gövde kusurları optimum boylama metodunun başarısını nasıl etkiler? Özet: Orman ürünlerinin üretiminde kullanılan bilgisayar destekli optimum boylama metodu üretilen ağaçların ekonomik değerini arttırmaktadır. Boylama kararı, gövde kusurları ve gövde formu gibi yüzey karakteristiklerine göre değişen tomruk kalite sınıflarına bağlıdır. Bu çalışmada, gövde kusurlarının optimum boylama metodu üzerindeki etkisini incelemek için iki farklı Kızılçam (Pinus brutia Ten) meçceresinde üretim çalışmaları sırasında yürütülen boylama uygulamaları karşılaştırılmıştır. Uygulamalarda, birinci meçceredeki gövdeler ikinci meşceredekilere oranla daha fazla gövde kusuru içermektedir. Birinci ve ikinci meşcerelerde, örnek ağaçlarda her bir tomruk için ortalama kusur sayısı sırasıyla 3,64 ve 2,70 olarak kaydedilmiştir. Sonuçlar optimum boylama metodunun bu meşcerelerde üretilen ağaçların ortalama ekonomik değerini sırasıyla %15,45 ve %8,26 oranında arttırdığını göstermiştir. Buna göre, bilgisayar destekli optimum boylama metodu fazla sayıda gövde kusuru içeren ağaçlarda potansiyel olarak geleneksel boylama yöntemine göre daha iyi sonuçlar sağlamaktadır.