HR: 13:55h
AN: B43D-02    [Abstracts]
TI: Strong Correlation Between Isoprene Emission and Gross Photosynthetic Capacity During Leaf Phenology of the Tropical Tree Species Hymenaea courbaril
AU: Kuhn, U
EM: kuhn@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Biogeochemistry Department, Joh.-J.-Becher-Weg 27, Mainz, 55128 Germany
AU: Rottenberger, S
EM: rottenbe@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Biogeochemistry Department, Joh.-J.-Becher-Weg 27, Mainz, 55128 Germany
AU: Biesenthal, T
EM: Tom.Biesenthal@sciex.com
AF: Max Planck Institute for Chemistry, Biogeochemistry Department, Joh.-J.-Becher-Weg 27, Mainz, 55128 Germany
AU: Wolf, A
EM: wolfsolf@web.de
AF: Max Planck Institute for Chemistry, Biogeochemistry Department, Joh.-J.-Becher-Weg 27, Mainz, 55128 Germany
AU: Schebeske, G
EM: schebi@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Biogeochemistry Department, Joh.-J.-Becher-Weg 27, Mainz, 55128 Germany
AU: Ciccioli, P
EM: paolo.ciccioli@imc.cnr.it
AF: Istituto di Metodologie Chimiche Area della Ricerca del CNR di Montelibretti, Via Salaria km 29.300, Monterotondo Scalo, 00019 Italy
AU: * Kesselmeier, J
EM: jks@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Biogeochemistry Department, Joh.-J.-Becher-Weg 27, Mainz, 55128 Germany
AB: Composition and amount of volatile organic compound (VOC) emission of the tropical tree species Hymenaea courbaril was studied under different developmental stages at a remote Amazonian rainforest site. The different stages covered young leaves (= grown full in size, but not fully turgescent) in the end of the dry season, mature leaves in the end of dry and wet season, and senescent leaves in the end of dry season. Though the diel isoprene emissions pattern could adequately be modelled by a current isoprene algorithm, the basal emission capacity of isoprene changed considerably over the course of leaf development. The inadequacy of using one single standard emission factor to represent the VOC emission capacity of tropical vegetation for an entire seasonal cycle is obvious. A strong linear correlation between the isoprene emission capacity and the gross photosynthetic capacity (GPmax) covering all developmental stages and seasons was observed. Hence, basic leaf photosynthetic activity may offer a valuable basis to model the seasonal variation of isoprene emission, especially in tropical regions where the environmental conditions vary less than in temperate regions. Of special interest was the light dependent monoterpene emission found exclusively in the period between bud break and leave maturity. The finding of this temporary emergence of monoterpene emission may be of general interest in understanding both the ecological functions of isoprenoid production and the regulatory processes involved.
DE: 1600 GLOBAL CHANGE (New category)
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0315 Biosphere/atmosphere interactions
DE: 0322 Constituent sources and sinks
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting