The aim of this project is to determine the fundamental effects of ozone O3 on Aleppo pine (Pinus halepensis Mill) against a background of other environmental factors, and to understand the physiological and biochemical mechanisms that enable this species to be successful in an extreme environment.
The project will enable the continuation and development of long-term experiments already initiated (STEP ECOTREE contract no CT 910 117) in the field (natural conditions in Greece) and in open-top chambers (clean air versus ambient air in Spain). A new experiment in Greece and Spain using an open-field exclusion system will allow mechanisms of interaction between ozone/drought/light/and nutrition to be investigated. This will be complemented by short-term experiments in closed chambers and controlled environment facilities (Lancaster, Nancy, Newcastle) to permit interactions between 03 and other environmental factors to be investigated in detail. In this way, controlled environment studies will be used to assist the interpretation of effects observed in the field.
The current ECOTREE work has confirmed our previous hypothesis that severe chlorosis exhibited by Aleppo pines in Attica (Greece) is not primarily nutritional but that it is a photo-oxidation of the chlorophylls under drought and high temperature. Whether this chlorosis has any relationship with ozone is still not known, but the project will explore the hypothesis that ozone pre-disposes the pine to photo-oxidation. The geographical extent of the chlorosis is not known yet but is not very apparent in Spain so the range and fundamental causes of this chlorosis need to be investigated, with comparisons made between Greece and Spain. The first STEP programme has enabled the collaborative groups to establish close links and to initiate long-term experiments. The proposed extension to the current programme will allow the links built up between the different laboratories to be fully exploited and enable experiments already initiated in the field and in open-top chambers to be continued.
Funding SchemeCSC - Cost-sharing contracts
14561 Kifisia / Athina
LA1 4YQ Lancaster /High Bantham
NE1 7RU Newcastle Upon Tyne
1211 Genève 4