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

Abstract
In the case of forests located in the close proximity of urban centres, the functions and conventional roles of the forests have to be largely reconsidered. An experimental study area was located in Făget Forest, near the city of Cluj-Napoca, North-West of Romania, as a subject to evaluate different natural risks, especially landslides. 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 on 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 multivariate 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 m2 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%), Q. robur (6.3%), Prunus avium (1.2%). Their positive roles on avoiding or limiting the flow on slopes, flooding, landslides etc. are different depending on the position, terrain, forest composition, trees density, slope, exposition, but it is fundamental beneficial. However, these species can assure productive (as wood), ameliorative, ecological, landscape, cultural, educational, relaxation roles, and consequently inestimable values.