Development of tree volume equations for natural black pine (Pinus nigra Arnold) stands in Aziziye-Burdur region

Black pine (Pinus nigra Arnold) forests are economically and ecologically one of important forests in Turkey. In this context, knowing the state and limitations of growth and yield of black pine forests is necessary for improving future management and planning strategies of timber resources. The one of the essential building blocks in forest growth and yield prediction models is the equations for estimating individual tree volume. Individual tree volume estimations can be use to tree and stand volume estimations and to any merchantable limit of this volume, forest management plans arrangement, to projections of forest products industries, and to estimations of biomass and carbon budgets with suitable biomass conversion factors. In this study, tree volume equations were developed for brutian pine stands in Burdur-Aziziye Region. For this aim, 183 sample trees destructively measured and then these trees rae randomly divided into two groups as development data and validation data. Nineteen regression models tested in this study. The tested models were compared using six performance criteria (Fit index, average bias, average absolute residuals, absolute maximum bias, and Akaike Information criteria) for model development and validation dataset. Accordingly relative ranks of models, the best volume equations are Model 5, Model 14, and Model 19, respectively. Hovewer, we recommended Model 14, because of well-known model, easy to applicate, and the model has only two parameter. As a result, tree volume can be estimated with high precision using Model 14 for natural black pine stands in region.