title: Chronic Drought Decreases Anabolic and Catabolic BVOC Emissions ofQuercus pubescensin a Mediterranean Forest.
abstract: Biogenic volatile organic compounds (BVOC) emitted by plants can originate from both anabolism (metabolite production through anabolic processes) and catabolism (metabolite degradation by oxidative reactions). Drought can favor leaf oxidation by increasing the oxidative pressure in plant cells. Thus, under the precipitation decline predicted for the Mediterranean region, it can be expected both strong oxidation of anabolic BVOC within leaves and, as a result, enhanced catabolic BVOC emissions. Using an experimental rain exclusion device in a natural forest, we compared the seasonal course of the emissions of the main anabolic BVOC released byQ. pubescens(isoprene and methanol) and their catabolic products (MACR+MVK+ISOPOOH and formaldehyde, respectively) after 3 years of precipitation restriction (-30% of rain). Thus, we assume that this repetitive amplified drought promoted a chronic drought. BVOC emissions were monitored, on-line, with a PTR-ToF-MS. Amplified drought decreased all BVOC emissions rates in spring and summer by around 40-50 %, especially through stomatal closure, with no effect in autumn. Moreover, ratios between catabolic and anabolic BVOC remained unchanged with amplified drought, suggesting a relative stable oxidative pressure inQ. pubescensunder the water stress applied. Moreover, these results suggest a quite good resilience of this species under the most severe climate change scenario in the Mediterranean region.
authors.affiliation: Aix Marseille Univ., Univ. Avignon, CNRS, IRD, IMBE Marseille, France.
authors.forename: Amélie
authors.initials: A
authors.lastname: Saunier
authors.affiliation: Aix Marseille Univ., Univ. Avignon, CNRS, IRD, IMBE Marseille, France.
authors.forename: Elena
authors.initials: E
authors.lastname: Ormeño
authors.affiliation: Aix Marseille Univ., CNRS, LCE, Laboratoire de Chimie de l'Environnement Marseille, France.
authors.forename: Henri
authors.initials: H
authors.lastname: Wortham
authors.affiliation: Aix Marseille Univ., CNRS, LCE, Laboratoire de Chimie de l'Environnement Marseille, France.
authors.forename: Brice
authors.initials: B
authors.lastname: Temime-Roussel
authors.affiliation: Aix Marseille Univ., Univ. Avignon, CNRS, IRD, IMBE Marseille, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Lecareux
authors.affiliation: Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Unisersité Paris-Saclay Gif sur Yvette, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Boissard
authors.affiliation: Aix Marseille Univ., Univ. Avignon, CNRS, IRD, IMBE Marseille, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Fernandez
keywords: BVOC; VOC oxidations; amplified drought; anabolism; catabolism