Multiscale fragmentation of forest types in Spain

This work contributes to the understanding of forest landscape ecology to support large-scale forest planning in Mediterranean forests. It examines the forest condition from a general perspective of habitat fragmentation in Spain. Our objective is to establish a framework for the assessment and comparison of the degree of forest fragmentation by generating reference curves of the Forest Area Density (FAD) metric, by forest type, and identifying multiscale fragmentation profiles at both the pixel and forest type level. To achieve this objective, pixel-level FAD values were produced in the entirety of Spain using a moving-window procedure and considering five scale levels and 20 forest types. Moreover, the results of this study inform useful operational scales and scaling relations, jointly providing a comprehensive national reference framework. We also propose a general theoretical model of fragmentation that derives from the relationship between the shape of the FAD reference curves and the considered scale levels. Based on this model, we define a new multiscale indicator for forest planning: the scale level (i.e., the size of the analysis window) at which the FAD metric takes a mean value of 50%. We expect this new indicator to be a useful tool for sustainable forest management.