Plant and Soil System Responses to Ozone After 3 Years in a Lysimeter Study with Juvenile Beech (Fagus sylvatica L.)

Abstract

A lysimeter study was performed to monitor effects of elevated ozone on juvenile trees of Fagus sylvatica L. as well as on the plant-soil system. During a fumigation period over almost three growing seasons, parameters related to plant growth, phenological development and physiology as well as soil functions were studied. The data analyses identified elevated ozone to delay leaf phenology at early and to accelerate it at late developmental stages, to reduce growth, some leaf nutrients (Ca, K) as well as some soluble phenolics (hydroxycinnamic acid derivatives, total flavonol glycosides). No or very weak ozone effects were found in mobile carbon pools of leaves (starch, sucrose), and other phenolic compounds (flavans). Altered gene expression related to stress and carbon cycling corresponded well with findings from leaf phenology and chemical composition analyses indicating earlier senescence and oxidative stress in leaves under elevated ozone. Conversely in the soil system, no effects of ozone were detected on soil enzyme activities, rates of litter degradation and lysimeter water balances. Despite the fact that the three reported years 2003-2005 were climatically very contrasting including a hot and dry as well as an extremely wet summer, and also mild as well as cold winters, the influence of ozone on a number of plant parameters is Water Air Soil Pollut: Focus (

Effects of ozone and Phytophthora citricola on non-structural carbohydrates of European beech (Fagus sylvatica) saplings

“…The comparison with the first 3 years of this experiment (Pritsch et al 2008;Schloter et al 2005) showed that it took 4 years of ozone exposure to form a significant ozone effect at least on NSC of leaves. effects of elevated ozone and below-ground pathogen infection on a plant-soil-system of juvenile beech (Fagus sylvatica L. …”

“…The experimental setup of the beech-forest soil lysimeters including the free-air ozone exposure device was described in detail by Winkler et al (2009a) as well as by (Pritsch et al 2008) and (Schloter et al 2005). …”

“…At the Helmholtz Zentrum München a lysimeter experiment was conducted since 2003 to study the impact of chronic ozone exposure on European beech saplings (Pritsch et al 2008;Schloter et al 2005). In addition, inoculation with the root pathogen P. citricola was performed in 2006 to investigate possible interactions between ozone and the plant disease.…”

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.)

“…2). During the four experimental growing periods tree samples were taken from these beeches and soil samples from outside the lysimeters so that the soil and plants in the lysimeters could be left undisturbed (Pritsch et al 2008).…”

“…The beeches were exposed for four years to ambient and elevated ozone concentrations respectively. In contrast to the chamber studies the beeches grew under field conditions providing a realistic span of climatic conditions and elevated O 3 concentrations (Pritsch et al 2008;Schloter et al 2005).…”