Economic impacts of ambient ozone pollution on wood production in Italy

Worldwide, tropospheric ozone (O₃) is a potential threat to wood production, but our understanding of O₃ economic impacts on forests is still limited. To overcome this issue, we developed an approach for integrating O₃ risk modelling and economic estimates, by using the Italian forests as a case study. Results suggested a significant impact of O₃ expressed in terms of stomatal flux with an hourly threshold of uptake (Y = 1 nmol O₃ m^-2 leaf area s^-1 to represent the detoxification capacity of trees), i.e. POD1. In 2005, the annual POD1 averaged over Italy was 20.4 mmol m^-2 and the consequent potential damage ranged from 790.90 M€ to 2.85 B€ of capital value (i.e. 255-869 € ha^-1, on average) depending on the interest rate. The annual damage ranged from 31.6 to 57.1 M€ (i.e. 10-17 € ha^-1 per year, on average). There was also a 1.1% reduction in the profitable forest areas, i.e. with a positive Forest Expectation Value (FEV), with significant declines of the annual national wood production of firewood (- 7.5%), timber pole (- 7.4%), roundwood (- 5.0%) and paper mill (- 4.8%). Results were significantly different in the different Italian regions. We recommend our combined approach for further studies under different economic and phytoclimatic conditions.