Free-air fumigation of mature trees. A novel system for controlled ozone enrichment in grown-up beech and spruce canopies.
A novel system for continuous and controlled free-air fumigation of mature tree canopies with ozone is described. Ozone generated from oxygen is diluted with air in a pressurized tank and conducted into the canopies by a system of 100 PTFE tubes hanging down from a grid fixed above the crowns. With 45 calibrated outlets per tube providing a constant flow of 0.3 l/min each, a total volume of about 10*10*15 m3 comprising 5 beech and 5 spruce canopies is fumigated. The spatial ozone distribution in the fumigated volume as well as surrounding reference tree canopies is controlled by continuous measuring instruments installed at 4 levels and a dense array of passive samplers. The system will later be used for CO2 fumigation as well. Results of the first year of continuous operation, with 2 * ambient ozone levels having been achieved, are reported.
Werner
Herbert
H
Technical University of Munich, Dept. of Ecology, Bioclimatology and Pollution Research, Am Hochanger 13, D-85354 Freising-Weihenstephan, Germany. werner@met.forst.tu-muenchen.de
Fabian
Peter
P
D016468:Forestry / Q000379:methods; D005651:Fumigation; D006801:Humans; D010126:Ozone / Q000008:administration & dosage / Q000032:analysis / Q000138:chemical synthesis / Q000494:pharmacology*; D014197:Trees / Q000187:drug effects* / Q000502:physiology
D010126:Ozone