Trace Gas Exchange in Forest Ecosystems

1. Biological processes involved in trace gas exchange.- 1.1 Microbiological and biochemical background of production and consumption of NO and N2O in soil.- 1.2 NO2, NO and HNO3 Uptake by Trees.- 1.3 Production and consumption of NH4+ and NH3 in trees.- 1.4 Isoprene and terpene biosynthesis.- 1.5 Biosynthesis of aldehydes and organic acids.- 2. Exchange of trace gases at the soil-atmosphere interface.- 2.1 NO, NO2 and N2O.- 2.2 CH4.- 3. Exchange of trace gases at the tree-atmosphere interface.- 3.1 Ammonia exchange at the tree-atmosphere interface.- 3.2 Isoprene and other isoprenoids.- 3.3 Aldehydes and organic acids.- 3.4 Ozone.- 4. Forest canopies as sources and sinks of atmospheric trace gases.- 4.1 Scaling up to the ecosystem level.- 5. Atmospheric chemistry of trace gases exchanged in forest ecosystems.- 5.1 Nitrogen oxides.- 5.2 Ozone and volatile organic ompounds: isoprene, terpenes, aldehydes, and organic acids.- 6. Environmental factors influencing trace gas exchange.- 6.1 Acid rain and N-deposition.- 6.2 Tropospheric Ozone.