Speaker
Description
Ozone is a major concern for people and ecosystem health. It is toxic to plants only when uptaken via stomata. The European Community has recently changed the ecosystem protection metric from how much ozone is in the air to how much ozone is uptaken into plants, the so-called stomatal ozone uptake or phytotoxic ozone dose (POD). A threshold y is suggested, above which no significant damage to plants is expected. POD is species-specific and depends on maximum stomatal conductance and on the environmental and plant parameters that modulate stomatal absorption. Species-specific or plant-type specific critical levels are then estimated based on PODy to assess the actual ozone risk to plant ecosystems under real world conditions. The National Emission Ceiling (NEC) Directive recommends estimation of PODy and critical levels for relevant ecosystems, and suggests monitoring of leaf visible injury. Research is thus developing species-specific stomatal conductance parameterization as well as characterization of leaf visible injury for field use. A traditional limitation to experimental studies with ozone and plants is due to the high ozone reactivity, so that the use of closed chambers requires high ventilation which may results in artifacts due to wind impact on stomata. Phytotron experiments are useful for mechanistic understanding of plant responses to ozone, while open-air facilities are required for ozone risk assessment studies. The free-air controlled exposure (FACE) facility in Florence (Italy), called FO3X, is part of the Analysis and Experimentation on Ecosystems (AnaEE) research infrastructure, and is at present the only ozone FACE facility able to work with plants up to a 2-m height in Europe. In this presentation, we aim at presenting FO3X and its contribution to the European legislation on ozone and plants within the context of the international debate on ozone impacts on plant ecosystem health and productivity.
| Are you participating to the "AnaEE Environmental Rising Star Award "? | No |
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