Experimental setup of field lysimeters for studying effects of elevated ozone and below-ground pathogen infection on a plant-soil-system of juvenile beech (Fagus sylvatica L.)

Abstract

An experiment, focusing on the effects of chronically enhanced O3 regimes on young beech (Fagus sylvatica) and on the microbial rhizosphere community structure, was conducted from November 2002 to August 2006 in eight field lysimeters at the Helmholtz Zentrum Munchen. The instrumentations of the lysimeters enabled the establishment of the water balance in the unsaturated zone and the assessment of the water uptake by plants. Further, the containment provided by the lysimeters made it possible to apply a root rot pathogen infection without contaminating the surrounding soil. A free-air fumigation system allowed to double the O3 concentration in the air above four lysimeters relative to the ambient air. To avoid damage of the leaves the maximum O3 concentration was limited to 150 nL L−1. For nearly 70% of the time the set-point concentration was reached within 10%. In the final harvest the whole soil column was retrieved and a nearly complete data-set of above-ground and below-ground parameters became available.