Puechabon - France

The site is located on a flat area 35 km North-West of Montpellier. The forest is dominated by the overstorey evergreen tree Quercus ilex (80% cover) managed as a coppice for centuries with the last clear-cut performed in 1942. Mean annual precipitation is 883 mm with 75 % rainfall between September and April. However, because of the large fraction of rocks and stones in the soil profile, available water averages only 150 mm. Long-term 30% throughfall exclusion and thinning experiments has started in 2003. In 2007 a new and unique manipulative experiment has been designed to simulate the effect of extreme droughts on the functioning and the vulnerability of this ecosystem. A mobile rainfall shelter was installed above the canopy in order to simulate 100% rain exclusion during different seasons. Measurements recorded include soil and organ-level gas exchange; tree transpiration; aboveground and belowground biomass; phenology; functional traits; litterfall; regeneration; organs, soil and litter biochemistry; VOC emission; dry and wet nitrogen deposition; ectomycorhizal communities. The site also includes an eddy-flux tower that continuously monitors atmosphere-vegetation exchange of CO2, water and energy since 1998. A large number of papers have already been published from research at the site and an important database is already available for the users, which will help defining new research areas in the areas of population genetics, nutrient cycle, soil microbiology, isotope studies.