Modelling the drought impact on monoterpene fluxes from an evergreen Mediterranean forest canopy.

TitleModelling the drought impact on monoterpene fluxes from an evergreen Mediterranean forest canopy.
Publication TypeJournal Article
Year of Publication2009
AuthorsGrote, R., LAVOIR ANNE-VIOLETTE., Rambal S., Staudt M., Zimmer I., & Schnitzler J-P.
JournalOecologia
Volume160
Pagination213-223
Accession Number19219456
KeywordsBiological, Carbon dioxide, Carbon Dioxide: metabolism, Computer Simulation, Drought impact, Droughts, France, Model coupling, Models, monoterpene emission, Monoterpenes, Monoterpenes: metabolism, photosynthesis, Photosynthesis: physiology, Plant Leaves, Plant Leaves: metabolism, Quercus, Quercus ilex (holm oak), Quercus: metabolism, Scaling, Trees, Trees: metabolism, water, Water: metabolism
Abstract

In many ecosystems drought cycles are common during the growing season but their impact on volatile monoterpene emissions is unclear. Therefore, we aimed to develop and evaluate a process-based modelling approach to explore the explanatory power of likely mechanisms. The biochemically based isoprene and monoterpene emission model SIM-BIM2 has been modified and linked to a canopy model and a soil water balance model. Simulations are carried out for Quercus ilex forest sites and results are compared to measured soil water, photosynthesis, terpene-synthase activity, and monoterpene emission rates. Finally, the coupled model system is used to estimate the annual drought impact on photosynthesis and emission. The combined and adjusted vegetation model was able to simulate photosynthesis and monoterpene emission under dry and irrigated conditions with an R(2) of 0.74 and 0.52, respectively. We estimated an annual reduction of monoterpene emission of 67% for the extended and severe drought period in 2006 in the investigated Mediterranean ecosystem. It is concluded that process-based ecosystem models can provide a useful tool to investigate the involved mechanisms and to quantify the importance of specific environmental constraints.