<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Kesselmeier, J</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Exchange of short-chain oxygenated volatile organic compounds (VOCs) between plants and the atmosphere: A compilation of field and laboratory studies</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Atmospheric Chemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acetaldehyde</style></keyword><keyword><style  face="normal" font="default" size="100%">acetic acid</style></keyword><keyword><style  face="normal" font="default" size="100%">biogenic deposition</style></keyword><keyword><style  face="normal" font="default" size="100%">Biogenic emission</style></keyword><keyword><style  face="normal" font="default" size="100%">carbonyls</style></keyword><keyword><style  face="normal" font="default" size="100%">compensation point</style></keyword><keyword><style  face="normal" font="default" size="100%">Formaldehyde</style></keyword><keyword><style  face="normal" font="default" size="100%">formic acid</style></keyword><keyword><style  face="normal" font="default" size="100%">organic acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Volatile Organic Compounds</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2001</style></year></dates><volume><style face="normal" font="default" size="100%">39</style></volume><pages><style face="normal" font="default" size="100%">219-233</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Field and laboratory investigations of the exchange of the short-chain organic acids – formic acid and acetic acid – as well as their homologous aldehydes are discussed. Both acids are substantially released from several plant species. Emission measurements under ﬁeld conditions are compiled to give an overview of three years of measurements. Emission rates from several tree species were found in the range between zero and 60 nmoles m−2 min−1 for acetic acid and between zero and 90 nmoles m−2 min−1 for formic acid though also a deposition has been observed to orange trees. Investigations under laboratory conditions showed an order of magnitude lower emission rates with signiﬁcant differences under light and dark conditions, and a deposition was observed under certain conditions. Hence, low emission rates or even a bi-directional exchange, emission as well as deposition have to be taken into account. Further differences between ﬁeld and laboratory studies are discussed considering age of trees, stress effects and a potential production of acids by photochemical conversion of precursors inside enclosures during sampling. Field data on the exchange of formand acetaldehyde show a complex behavior. We found emission as well as uptake. The bi-directional exchange is signiﬁcantly triggered by the ambient mixing ratios of both aldehyde species and exhibits a compensation point. Further studies are needed for generalization of the exchange of these and potentially also for other compounds</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Kesselmeier, J</style></author><author><style face="normal" font="default" size="100%">Staudt, M</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Biogenic volatile organic compounds (VOC): An overview on emission, physiology and ecology</style></title><secondary-title><style face="normal" font="default" size="100%">JOURNAL OF ATMOSPHERIC CHEMISTRY</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acids</style></keyword><keyword><style  face="normal" font="default" size="100%">alkanes</style></keyword><keyword><style  face="normal" font="default" size="100%">alkenes</style></keyword><keyword><style  face="normal" font="default" size="100%">carbonyls</style></keyword><keyword><style  face="normal" font="default" size="100%">ecology</style></keyword><keyword><style  face="normal" font="default" size="100%">emission</style></keyword><keyword><style  face="normal" font="default" size="100%">emission inventories</style></keyword><keyword><style  face="normal" font="default" size="100%">Esters</style></keyword><keyword><style  face="normal" font="default" size="100%">isoprene</style></keyword><keyword><style  face="normal" font="default" size="100%">nonmethane hydrocarbons</style></keyword><keyword><style  face="normal" font="default" size="100%">oxygenated compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">physiology</style></keyword><keyword><style  face="normal" font="default" size="100%">review</style></keyword><keyword><style  face="normal" font="default" size="100%">terpenes</style></keyword><keyword><style  face="normal" font="default" size="100%">Volatile Organic Compounds</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><publisher><style face="normal" font="default" size="100%">SPRINGER</style></publisher><pub-location><style face="normal" font="default" size="100%">VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">33</style></volume><pages><style face="normal" font="default" size="100%">23-88</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">This overview compiles the actual knowledge of the biogenic emissions of some volatile organic compounds (VOCs), i.e., isoprene, terpenes, alkanes, alkenes, alcohols, esters, carbonyls, and acids. We discuss VOC biosynthesis, emission inventories, relations between emission and plant physiology as well as temperature and radiation, and ecophysiological functions. For isoprene and monoterpenes, an extended summary of standard emission factors, with data related to the plant genus and species, is included. The data compilation shows that we have quite a substantial knowledge of the emission of isoprene and monoterpenes, including emission rates, emission regulation, and biosynthesis. The situation is worse in the case of numerous other compounds (other VOCs or OVOCs) being emitted by the biosphere. This is reflected in the insufficient knowledge of emission rates and biological functions. Except for the terpenoids, only a limited number of studies of OVOCs are available; data are summarized for alkanes, alkenes, carbonyls, alcohols, acids, and esters. In addition to closing these gaps of knowledge, one of the major objectives for future VOC research is improving our knowledge of the fate of organic carbon in the atmosphere, ending up in oxidation products and/or as aerosol particles.</style></abstract></record></records></xml>