Ameliorative, Ecological and Landscape Roles of Faget Forest, Cluj-Napoca, Romania, and Possibilities of Avoiding Risks Based on GIS Landslide Susceptibility Map

The functions and conventional roles of the forests have to be largely reconsidered when such forests are located in the close proximity of urban centres. The subject of this study was to evaluate different natural risks, especially landslides at an experimental study area that is located in Faget Forest, near the city of Cluj-Napoca, North-West of Romania. Although most of this area is stabilized, human activity became in the last period the most aggressive and active factor that can induce changes in slopes stability. The evaluation based on new changes at the terrain and constructions has clearly revealed the effect of the unprecedented urban sprawl and the expansion of infrastructure elements and residential buildings. Landslide susceptibility map was elaborated using a bivariate statistical analysis and the Geographical Information System (GIS) technology on a predetermined path inside the forest, as well as obtaining valuable information about the tree species. Based on 14 surveys, each of them covering an area of 500 m(2) on a longitudinal transect of the forest, there were identified relatively few tree species with a significant share: Carpinus betulus (42.9%), Fagus sylvatica (24.9%), Quercus petraea (23.2%) and other species (9%). Their positive roles in avoiding or limiting the flow on slopes, flooding, landslides are different depending on the position, terrain, forest composition, trees density, slope, exposition, but it is fundamentally beneficial. Furthermore, these species can assure productive (as wood), ameliorative, ecological, landscape, cultural, educational, relaxation roles, and consequently inestimable values.