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.