title: Instantaneous and historical temperature effects on alpha-pinene emissions in Pinus halepensis and Quercus ilex.
abstract: We compared the role of instantaneous temperature and temperature history in the determination of alpha-pinene emissions in Mediterranean conifer Pinus halepensis that stores monoterpenes in resin ducts, and in Mediterranean broad-leaved evergreen Quercus ilex that lacks such specialized storage structures. In both species, alpha-pinene emission rates (E) exhibited a significant exponential correlation with leaf temperature and the rates of photosynthetic electron transport (Jco2+o2) started to decrease after an optimum at approximately 35 degrees C. However, there was a higher dependence of E on mean temperature of previous days than on mean temperature of current day for P. halepensis but not for Q. ilex. Jco2+o2 showed a maximum relationship to mean temperature of previous 3 and 5 days for P. halepensis and Q. ilex respectively. We conclude that although the best correlation of emission rates were found for instantaneous foliar temperatures, the effect of accumulated previous temperature conditions should also be considered in models of monoterpene emission, especially for terpene (see text) species.
authors: Ecophysiology and Global Change Unit CREAF-CEAB-CSIC, Center for Ecological Research and Forestry Applications, Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia, Spain. js.blanch@creaf.uab.cat
authors: Josep-Salvador
authors: JS
authors: Blanch
authors: Joan
authors: J
authors: Llusia
authors: Ulo
authors: U
authors: Niinemets
authors: Steffen M
authors: SM
authors: Noe
authors: Josep
authors: J
authors: Penuelas
mesh_terms: D000081008:Bicyclic Monoterpenes; D002980:Climate; D039821:Monoterpenes / Q000378:metabolism*; D028223:Pinus / Q000378:metabolism*; D029963:Quercus / Q000378:metabolism*; D013696:Temperature
chemical_list: D000081008:Bicyclic Monoterpenes; D039821:Monoterpenes; C005451:alpha-pinene