Relationship between the productivity of Pinus brutia Ten. and site characters, the Taurus Mountains, Turkey

Turkish red pine is an important forest tree species because of its role in the ecosystem whose range includes many countries in the eastern Mediterranean basin. In addition, red pine is a preferred forest tree species due to rapid growth, usage in afforestation in arid areas and the production of non-wood forest products such as resin. The aim of the study was to examine the relationship between the productivity of red pine and ecosystem in the lower and middle belt of the Taurus Mountains, and to determine the interrelations between the productivity of red pine and ecosystem. Multivariate analyses (multiple regression analysis and artificial neural networks) were used to model the efficiency (biomass production) of red pine. From the multivariate analyses, a productivity model of the species was created with the slope, soil depth, and precipitation in the driest variables. A significant correlation was found between site index and site factors in the driest quarter. These variables had a statistically significant relationship with the site index in the multiple regression analysis. The forecast power of the model was 0.33. Of the methods used, the artificial neural network consisting of 2L10N (2 Layers 10 Neurons) had the highest margin of explanation (R²= 0.71) and the lowest margin of error. This model has the potential to open land aimed for afforestation studies with red pine in forestry areas. The results will shed light on afforestation studies to be carried out in the Western Mediterranean region and in similar ecosystems.