Problems to be solved
The role of forests in preserving the environment is undeniable and ranges from ecological buffer for nutrient and CO2 cycles, to being a key controlling factor of the hydrological cycle, and to being source of biodiversity stabilising ecosystems. Forests are also a major source of volatile organic compounds (VOC). Plant species differ in VOC emission and emissions are strongly co-determined by concurrent climate. BiogenicVOC are formed and emitted with estimated 1.1 Pg C per year on global scale. Although this emission accounts for approximately 2% of the total C-exchange of 69 Pg between the biota and the atmosphere, it has not been considered in global C-cycling so far. Biogenic VOC play also an important role in the oxidation processes of the lower troposphere leading to high ozone and photochemical smog during periods of high radiation and temperature at low wind speeds when BVOC emissions are usually high. Therefore, there is a pressing need to understand the effect of plant diversity and the effect of global change factors such as elevated CO2 on the source strength and pattern of VOC emission of European forests for establishing effective photooxidant reduction strategies and for correctly assessing the carbon sinks in the biosphere.
Scientific objectives and approach:
To correctly assess the impact of elevated CO2 on plant ecophysiology, and hence VOC emission on European scale both long term fumigation experiments in the natural environment and mechanistic studies in controlled environment chambers are necessary. The projects benefits from already existing infrastructure and from databases available for the field sites in Switzerland (Swiss canopy crane project SSC near Basel) and Italy (CO2 springs in Tuscany) and from controlled environment chambers in the United Kingdom (Lancaster).
The objectives of FUTURE-VOC will be:
(1) To measure and quantify VOC emissions from tree and under story vegetation under natural and enhanced CO2 levels at field sites in the Mediterranean area and central Europe.
(2) To elucidate the mechanisms of carbon partitioning of photosynthesis used in the VOC production processes in plants grown under natural and elevated CO2 by means of environment chamber experiments.
(3) To update existing plant physiological gas exchange models for current and future carbon-cycling and VOC emission.
(4) To demonstrate the effect of enhanced CO2 mixing ratios on C-cycling and VOC-emission for specific periods and selected regions of Europe.
The overall goal of the project is to fill the gap of knowledge with respect to the effect elevated CO2 on C-Cycling and VOC emission of Mediterranean and central European forests. Therefore, the results gained and models developed will assist the EU policies (e.g. European Commission Framework Directive on ambient air quality assessment and management, Convention for Long-range Trans-boundary Air-pollution, Climate change - Towards a EU post Kyoto strategy (COM(98) 353), and Amended proposal for a Council decision amending Dec.93/389/EEC for a monitoring mechanism of Community CO2 and other greenhouse gas emissions (COM98)108) in preparing future effective abatement strategies for greenhouse gases and photooxidants and developing future sustainable management strategies of agro forests serving as most effective CO2-sink with minimised negative effects on the air quality.
Funding SchemeCSC - Cost-sharing contracts
LA1 4YQ Lancaster