Spatial and temporal deforestation dynamics of Zagros forests (Iran) from 1972 to 2009

Abstract

The emerging interest in sudden losses in vegetation and forest cover in semi-arid areas has led to a new understanding of the patterns and processes of deforestation. The Zagros oak forests in western Iran have undergone dramatic changes in cover and structure in recent decades, with negative consequences for the communities that depend upon them. This study had three objectives: (1) evaluate the nature and magnitude of these changes from 1972 to 2009 through trends in forest area and connectivity; (2) evaluate the changes in forest area and landscape connectivity across a climatic gradient; and (3) evaluate the effect of topographical variations. Landsat MSS, TM, and ETM+ images for the region were preprocessed and corrected prior to classification of 167 landscape units (LU; 400km2 each). We developed two measures – deforestation sensitivity (DS) and connectivity sensitivity (CS) – for each LU. A considerable but relatively linear loss in forest area and connectivity was detected. Connectivity loss occurred more rapidly than forest loss due to the loss of connecting patches. More connectivity was lost in southern Zagros due to climatic differences and different forms of traditional land use. Steep slopes and high elevations experienced more forest loss and connectivity. In northern Zagros the coppice form of forest management should be supported as a method that maintains connectivity. In southern Zagros, restoration projects should focus on regeneration in forest gaps to restore connectivity between isolated forest fragments. The study provides large scale information for restoration projects across a spatial climatic gradient.