In the last decades in Italian mountainous regions, forests are invading abandoned pastures and cultivated surfaces that often played a key ecological role for biodiversity conservation, a complex land-use change phenomenon. To improve sustainable regional planning and management it is increasingly important to quantify the phenomenon and classify those areas according their ecological vocation. This study explores multi-objective and multi-criteria assessment for the identification of the most suitable areas for agricultural purposes between those surfaces that have been invaded by forests. Free and Open-Source Software for Geospatial (FOSS4G) software has been used to carry out the research. The work here presented has been funded by the EIT Climate-KIC SATURN project (2018-2021) and was carried out in the pilot areas of the Province of Trento (Italy). Geospatial data set was georeferenced and managed with GRASS and QGIS and the files were collected combining data freely available at the Autonomous Province of Trento geocatalogue as well as others self-produced during the project. The comparative analysis and methodology were carried out by means of QGIS 3.16 Geographic Information System which has been used to complete the analysis to develop a methodology that can be widely used by territorial operators and Public Administrations. To validate the model and verify the results, on-site inspections were carried out. The developed model can be used in different environmental assessments for territorial planning purposes.