Actual and potential impact of air pollution on Italian forests: results from the long-term national forest monitoring networks under the ICP Forests.

Forests in Italy cover ca. 8.76 x 106, stock 1,242 Mt carbon and offer a series of invaluable products and services to the entire society (Gasparini and Tabacchi, 2011; Gasparini et al., 2013). Preserving forest integrity is therefore essential. Although effects are in general less obvious and frequent in comparison with other biotic and abiotic stressors, air pollution may have an impact on several compartments of forest ecosystem, and may endanger forest health, productivity and diversity (Bobbink et al., 2010; Karnosky et al., 2003). In this chapter, we will present status, trends of pressure, impacts and risks placed to forests by the most important air pollution issues in Italy as emerged from data collected by national forest monitoring networks since the mid of the 1990s. To do this, we will concentrate on data originated from harmonized measurements carried out at the national Level I and Level II networks that are parts of the UNECE ICP Forests.