Favourable and restrictive factors for quercus pubescens in the transylvanian basin, evaluated by GIS techniques

Abstract

A very simple analysis of the forested areas across the Transylvanian Basin shows that they cover approximately 45.8% of the area, according to data provided by the European Environment Agency. In order to extend the areas covered by forests, especially over badlands specific for the Transylvanian Basin and to increase the economic and environmental value of these lands, a GIS model of spatial analysis has been developed to identify the areas favourable for downy oak (Quercus pubescens) plantations, a forest species which has specific requirements in terms of adaptability conditions. The developed spatial analysis model is based on the unitary analysis of the climatic, soil and geomorphologic components, spatially materialized as raster format databases, and their integration according to spatial analysis equations in order to get a modelled database which represents spatially the favourable areas for the creation of downy oak plantations. The result of this study highlights the territories which provide favourable but also restrictive conditions for Quercus pubescens. The model has a high predictability rate taking as comparative reference the direct monitoring at the level of forest planning units (PUs) within Cluj County, identified from the analysis of forestry plans. The high validation rate of the proposed model was obtained by overlapping the favourability classes which themselves were obtained after modelling with the limits of the forest planning units where the consistency of the downy oak is greater than 0.7. According to the presented validation procedure, a 93% validation rate was obtained, fact which highlights the usefulness of applying the model in areas having similar features and its extrapolation in areas where the environmental conditions present only slight differences.