Unraveling the ‘stable’ landscape: a multi-factor analysis of unchanged agricultural and forest land (1987–2007) in a rapidly-expanding urban region

The present study proposes an original framework to investigate landscape transformations in economically-dynamic regions based on the spatial analysis of unchanged land-use patches over a given time-period. A multi-factor analysis of the stable patches classified at nine land-use classes during 1987–2007 in Attica, Greece, was developed using landscape metrics (number of patches, class area, mean shape index, mean patch size and its coefficient of variation) and territorial variables (elevation, distance from the central city). A Principal Component Analysis (PCA) was carried out to explore the specific relations existing between landscape metrics and territorial variables for each use of land. Areas maintaining the same use of land during 1987–2007 covered 73 % of the total investigated region. Artificial surfaces/bare land and agricultural areas are the most persistent uses of land over time (respectively 95 % and 81 %) while the less persistent uses are shrubland (49 %) and coniferous forests (58 %). On average, stable patches are significantly bigger and more distant from the central city than the patches observed at the beginning of the study period. Deviations to this general pattern have been observed for specific land-use classes. The PCA identified patch area and shape as independent descriptors of the stable landscape, being correlated respectively with the distance from the inner city and elevation. Multivariate analysis proved to be a relevant tool for evaluating landscape transformations in rapidly evolving urban regions. Stable agro-forest landscapes are a promising target for environmental conservation policies.