Toward stomatal-flux based forest protection against ozone: The MOTTLES approach.

European standards for the protection of forests from ozone (O) are based on atmospheric exposure (AOT40) that is not always representative of O effects since it is not a proxy of gas uptake through stomata (stomatal flux). MOTTLES "MOnitoring ozone injury for seTTing new critical LEvelS" is a LIFE project aimed at establishing a permanent network of forest sites based on active O monitoring at remote areas at high and medium risk of O injury, in order to define new standards based on stomatal flux, i.e.

An epidemiological assessment of stomatal ozone flux-based critical levels for visible ozone injury in Southern European forests.

Southern forests are at the highest ozone (O3) risk in Europe where ground-level O3 is a pressing sanitary problem for ecosystem health. Exposure-based standards for protecting vegetation are not representative of actual field conditions. A biologically-sound stomatal flux-based standard has been proposed, although critical levels for protection still need to be validated.

Health and vitality assessment of two common pine species in the context of climate change in southern Europe.

The Mediterranean Basin is expected to be more strongly affected by ongoing climate change than most other regions of the earth. The South-eastern France can be considered as case study for assessing global change impacts on forests. Based on non-parametric statistical tests, the climatic parameters (temperature, relative humidity, rainfall, global radiation) and forest-response indicators (crown defoliation, discoloration and visible foliar ozone injury) of two pine species (Pinus halepensis and Pinus cembra) were analyzed.

Annual and seasonal trends of ambient ozone concentration and its impact on forest vegetation in Mercantour National Park (South-eastern France) over the 2000-2008 period.

In the South-Eastern French Mediterranean region, high ozone concentrations were measured since many years and specific symptoms like chlorotic mottles were detected on Arolla pines. We presented results for the 2000-2008 period concerning the trend analysis for ambient ozone concentrations and related forest damages, with the Mann and seasonal Kendall tests. Ozone precursor's emissions from Europe have been reduced over the last 20 years.