In recent years, Turkey has adopted the principles of ecologically based forest management. This planning approach is immediate need to develop growth and yield relationships to understand the differences in these relationships among different ecoregions. The relationships of diameterheight are essential elements of growth and yield models. Diameter-height relationships are critical in forest inventory for estimating volume, site index, forest growth and yield, and carbon budget models. In practice, tree diameters can be easily measured in the field at little cost, while tree heights are relatively more difficult and time-consuming to obtain.Brutian pine (Pinus brutia Ten.) is an important tree species of Turkey and an important source of raw material for the forest products industry in Turkey. However, the available information about diameter-height relationships concerning the above species in not considered sufficient.With this study, diameter-height models developed for natural Brutian pine stands in Antalya District. We used six widely used nonlinear growth functions, generalized height-diameter models, and nonlinear mixed effects model. The available data for each species were split into two sets: the majority (%75) was used to estimate model parameters, and the remaining data (%25) were reserved to validate the models.The performance of the models was compared and evaluated with six model performance criteria. According to the model performance criteria, nonlinear mixed-effects models were found to be superior to al other nonlinear regression models, in terms of their predictive ability. Keywords: Diameter, height, mixed-effects model, generalized models
Tez (Yüksek Lisans) - Süleyman Demirel Üniversitesi, Fen Bilimleri Enstitüsü, Orman Mühendisliği Anabilim Dalı, 2013.
Kaynakça var.
In recent years, Turkey has adopted the principles of ecologically based forest management. This planning approach is immediate need to develop growth and yield relationships to understand the differences in these relationships among different ecoregions. The relationships of diameterheight are essential elements of growth and yield models. Diameter-height relationships are critical in forest inventory for estimating volume, site index, forest growth and yield, and carbon budget models. In practice, tree diameters can be easily measured in the field at little cost, while tree heights are relatively more difficult and time-consuming to obtain.Brutian pine (Pinus brutia Ten.) is an important tree species of Turkey and an important source of raw material for the forest products industry in Turkey. However, the available information about diameter-height relationships concerning the above species in not considered sufficient.With this study, diameter-height models developed for natural Brutian pine stands in Antalya District. We used six widely used nonlinear growth functions, generalized height-diameter models, and nonlinear mixed effects model. The available data for each species were split into two sets: the majority (%75) was used to estimate model parameters, and the remaining data (%25) were reserved to validate the models.The performance of the models was compared and evaluated with six model performance criteria. According to the model performance criteria, nonlinear mixed-effects models were found to be superior to al other nonlinear regression models, in terms of their predictive ability. Keywords: Diameter, height, mixed-effects model, generalized models