Exploring the effects of land abandonment on habitat structures and on habitat suitability for three passerine species in a highland area of Central Italy

This study addresses the effects of land abandonment on landscape structure and on the habitat suitability for three passerine species (red-backed shrike Lanius collurio, corn bunting Miliaria calandra and yellowhammer Emberiza citrinella) in a span of 40 years (from 1954 to 1994) in an Appenninic rural area. Aerial photographs were used to compare changes in variables related to landscape structure. Multivariate logistic regression was used to model species–habitat relations. The most important landscape changes highlighted by the present study were an expansion of woodland and scrubland at the expense of complex field mosaics, which were abandoned, and an overall decrease of vertical elements and structural diversity in the areas still being farmed. These highly significant changes affected also the correlations between variables. All of the three bird species showed an association to landscape features which were subject to significant change, such as hedgerows, untilled land, bushes and trees. The long-term effects of land abandonment are likely to be a loss of habitat for farmland birds. Some environmental and socio-economic factors related to land abandonment are also discussed.