Ground level ozone effects in individual growth phases of central european submountain beech forests

We observed ground level ozone concentrations on a series of five beech experimental plots, one representing the original stand and the other four generated and modified by cuts of graduated intensity. The study was carried out in a beech ecosystem in the Kremnické vrchy Mts, the Western Carpathian region, in years 1999-2008. The plots, established in 1989, were evaluated and compared statistically before and after the cutting modification in 2004. The level of significance of the effect of this intervention was 99% on the plot representing small-area clear-cut and on the plot treated with medium cut. Differences, though not significant, were also found in the other plots. Apart from the effects due to the stocking reduction, the whole post-intervention period was characterised with the influence of progressively increasing average air temperatures and similarly increasing ozone concentrations. Globally, the ozone concentrations on all plots were lower (average value 39 μg m-3) during the period 1999-2003 than in the following years 2004-2008 (average value 55 μg m-3). Maximum values measured in the growing season ranged from 36 to 140 μg m-3. The allowable limit exceeded 10 times in years 1999-2003 but 17 times in years 2004-2008, implying worsening conditions in Central European beech forest stands

Immission-load-related dynamics of S-SO42− in precipitation and in lysimetric solutions penetrating through beech ecosystems

The paper presents the results of a 23-year study of sulphate sulphur dynamics in beech ecosystems exposed to different immission loads. The amounts of S-SO42− in precipitation water entering the ecosystems were: the Kremnické vrchy Mts, a clear-cut area 519 kg ha−1 (24.7 kg ha−1 per year), a beech forest 476 kg ha−1 (22.7 kg ha−1 per year); the Štiavnické vrchy Mts an open place 401 kg ha−1 (24.6 kg ha−1 per year), a beech forest 324 kg ha−1 (19.1 kg ha−1 per year). The average SO42− concentrations in lysimetric solutions penetrating through surface humus to a depth of Cambisol 10 and 25 cm were increased as follows: in the Kremnické vrchy Mts from 12.71 to 16.17 mg l−1 and in the Štiavnické vrchy Mts from 18.73 to 28.80 mg l−1. The S-SO4−2 amounts penetrating the individual soil layers in the Kremnické vrchy Mts were as follows: in case of surface humus on clear-cut area 459 kg ha−1 (20.9 kg ha−1 per year), in beech forest 433 kg ha−1 (19.7 kg ha−1 per year); below 10 cm organo-mineral layer of the mentioned plots penetrated 169–171 kg ha−1 (7.7–7.8 kg ha−1 per year), and below 25 cm mineral layer 155–255 kg ha−1 (7.1−11.6 kg ha−1 per year) – a higher amount was found on clear-cut area with an episodic lateral flow of soil solutions. In beech forest of the Štiavnické vrchy Mts penetrated below surface humus 424 kg ha−1 S-SO42− (18.9 kg ha−1 per year), below 10 cm mineral layer 458 kg ha−1 S-SO42− (19.9 kg ha−1 per year), and below 25 cm mineral layer as much as 599 kg ha−1 S-SO42− (26.0 kg ha−1 per year). This fact was caused by frequent lateral flow of soil solutions. The results indicate that the assumption about lower immission load of the beech ecosystem in the Kremnické vrchy Mts is wrong, at least in the case of S-SO42−. The testing has revealed that the studied beech ecosystems differ very significantly in sulphur amounts penetrating under 0.10 m and 0.25 m. The inter-annual differences were insignificant