Pollution problems in forest ecosystems resulting from 100 year long operation of three smelter complexes in Central Spis are reviewed. Original data are presented with respect to temporal and spatial trends of nitrogen, sulphur and heavy metal pollution, and elemental composition of individual aerosols on leaf surface. Spruce stands in Central Spis are loaded by pollutants 1.7 times more than are critical values and the highest concentrations of As, Fe, Hg, and N were found in this region. Low Tatra National Park was the cleanest region where no element maxima were found

Significant differences in the effects of N alone compared with NS Acid have been found with respect to eutrophication and acidification. N alone had no effect on the pleurocarpous mosses, whereas NS Acid caused their death within 2 years. Both treatments enhanced stem area increment and N alone also doubled fine root growth. By contrast NS Acid treatments increased litterfall in a a dose response fashion

Wet-deposited - sulphur and nitrogen pollutants and ambient ozone are important anthropogenic factors affecting forest health. Regular assessment of chemistry of throughfall and precipitation water based on two-week sampling started in 1997. Passive samplers for detection of ozone concentration have been exposed on a network of monitoring stations during vegetation periods since 1998. In addition, in selected locations, UV absorption monitors for continuous O3 measurements were installed in 1999

Increased reactive nitrogen (N) loadings to terrestrial ecosystems are believed to have positive effects on ecosystem carbon (C) sequestration. Global “hot spots” of N deposition are often associated with currently or formerly high deposition of sulphur (S); C fluxes in these regions might therefore not be responding solely to N loading, and could be undergoing transient change as S inputs change. In a four-year, two-forest stand (mature Norway spruce and European beech) replicated field experiment involving acidity manipulation (sulphuric acid addition), N addition (NH4NO3) and combined treatments, we tested the extent to which altered soil solution acidity or/and soil N availability affected the concentration of soil dissolved organic carbon (DOC), soil respiration (Rs), microbial community characteristics (respiration, biomass, fungi and bacteria abundances) and enzyme activity. We demonstrated a large and consistent suppression of soil water DOC concentration driven by chemical changes associated with increased hydrogen ion concentrations under acid treatments, independent of forest type. Soil respiration was suppressed by sulphuric acid addition in the spruce forest, accompanied by reduced microbial biomass, increased fungal:bacterial ratios and increased C to N enzyme ratios. We did not observe equivalent effects of sulphuric acid treatments on Rs in the beech forest, where microbial activity appeared to be more tightly linked to N acquisition. The only changes in C cycling following N addition were increased C to N enzyme ratios, with no impact on C fluxes (either Rs or DOC). We conclude that C accumulation previously attributed solely to N deposition could be partly attributable to their simultaneous acidification.

We present the temporal trends and spatial changes of deposition of sulphur and nitrogen in Czech forests based on records from long-term monitoring. A statistically significant trend for sulphur was detected at most of the sites measuring for wet, dry, and total deposition fluxes and at many of these the trend was also present for the period after 2000. The spatial pattern of the changes in sulphur deposition flux between 1995 and 2011 shows the decrease over the entire forested area in a wide range of 18.1–0.2 g m−2 year−1 with the most pronounced improvement in formerly most impacted regions. Nitrogen still represents a considerable stress in many areas. The value of nitrogen deposition flux of 1 g m−2 year−1 is exceeded over a significant portion of the country. On an equivalent basis, the ion ratios of NO3−/SO42− and NH4+/SO42− in precipitation show significantly increasing trends in time similarly to those of pH.

Palaeorecords which depict changes in sulphur dynamics form an invaluable resource for recording atmospheric pollution. Tree rings constitute an archive that are ubiquitously available and can be absolutely dated, providing the potential to explore local- to regional-scale trends in sulphur availability. Rapid isotopic analysis by a novel “on-line” method using elemental analyser isotope ratio mass spectrometry (EA-IRMS) is developed, achieving sample precision of <0.4‰ using sample sizes of 40 mg wood powder. Tree cores from NE Italy show trends in pollution, evidenced through increasing concentrations of sulphur towards the youngest growth, and inverse trends in sulphur isotopes differentiating modern growth with light sulphur isotopes (+0.7‰) from pre-industrial growth (+7.5‰) influenced by bedrock composition. Comparison with speleothem records from the same location demonstrate replication, albeit offset in isotopic value due to groundwater storage. Using EA-IRMS, tree ring archives form a valuable resource for understanding local- to regional-scale sulphur pollution dynamics.