Monoterpene field emission from Quercus ilex near Madrid (Spain)
Abstract
A great extension of Quercus ilex natural forest is found in the close vicinity to Madrid metropolitan area. This work presents the results obtained in a three-year field emission experimental study on this evergreen oak species (2000--02). Monoterpene emission has been documented during summer and early autumn seasons using a branch enclosure technique. Main features of this emission study focus on speciation, light and temperature dependence, and relationship with carbon assimilation and water stress. Severe soil water deficit induced a physiological depletion at high temperature in this sclerophyll and monoterpene non-storing oak species, reducing emission at minimum levels. In the opposite, if soil was enough wetted emission was reasonably well described by the isoprene model of Guenther although assimilation was reduced at high temperature. A field experiment designed to ascertain the role of air humidity on emission revealed no influence of this parameter under no soil water deficit conditions. Canopy emission fluxes were calculated from the modified Bowen-ratio technique using a micrometeorological tower deployed within the oak forest. A standard emission flux of 0.3 μg m-2s-1 according to the model of Guenther (30^oC and 1000 μmol m-2s-1 of PAR) was obtained (r^2= 0.67).
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA.....5500N