Soil water measurements in Swiss forest plots show a decrease of the ratio between base cations and aluminium within last 4 years. The decrease is significant in at least one soil layer in 12 of 14 plots and is strongest in areas with high acid deposition. In some of the soils the critical ratio of 1 is being reached today. The development is compared with model estimates. In Switzerland, 80% of acid deposition is made up by nitrogen compounds

A DIRT (Detritus Input and Removal Treatments) experiment was initiated at the Sikfokut Forest LTER site in Hungary in November 2000. This study was designed to evaluate how sources and quantities of litter inputs control nutrient cycling and carbon storage in forest soils across sites with different climate, C and N status. Sikfokut Forest was selected for its high N deposition rate compared the Harvard Forest LTER, Bousson Forest and Andrews Forest LTER DIRT experiment sites in the United States. Trends in soil enzyme phosphatase and beta-glucosidase activity at Sikfokut indicate that the microbial community there is already clearly responding to reduced litter availability after only two years of treatment

Instrumental neutron activation analysis was used for determination of element concentration in 10 year old segments of lime wood in extremely polluted area in Central Spis. We found the highest concentrations of Al, As, Au, Br, Cl, K, Na, Rb, Sb and Sm in the oldest 80-90 year old forest. The same elements were determined in atmospheric deposition with moss bio-monitoring technique. In the area of Central Spis we found in comparison with Norwegian limit values exceeded levels for the elements as given similarly for comparison with Magnitogorsk in Ural Mountains

Passive samplers offer considerable advantages for measuring ozone (O3) concentrations in remote areas. Measurements with passive samplers typically result in data about weekly-to-monthly O3 concentrations, which are not consistent with the definitions of cumulative indices currently being used to estimate the exposure of vegetation to O3. For this reason, attempts were and are being made to develop statistical and empirical methods to estimate exposure indices like the AOT40 adopted in Europe (O3 Accumulated Over Threshold 40 ppb) starting from mean concentrations obtained from passive samplers. This paper describes an empirical method adopted in Italy to estimate 1996-2000 AOT40 values at 20 forest sites of the Italian network of intensive monitoring of forest ecosystems

Ozone is a well-known phytotoxic agent causing damage to vegetation in parts of North America and Europe. Transboundary or long-range transport of ozone from Western Europe and the generation of ozone from local and regional precursors results in increasing ozone concentrations in Central and Eastern Europe, including the Carpathian Mountaians. Other air pollutants such as sulphur dioxide, nitrogen oxides, ammonia and heavy metals may also affect the health of Carpathian forests. During the 2000-2002 summer seasons, concentrations of ozone, sulphur dioxide, nitrogen oxides and ammonia were monitored with passive samplers. Results of those measurements will be used for development of GIS models of spatial and temporal distribution of air pollutants

Ailanthus altissimia Desf. is a non-native species spread throughout the Southern Europe as invasive plant. It demonstrated to be very sensitive to ozone and ozone-polluted environment, develops brownish stipples on the upper leaf surface. In the 2001 summer 12 young plants were placed in a site near the city of Florence (Italy), where high levels of ozone were experienced. Six of them were regularly watered and six were watered only when the wilting of their leaves was evident. Regular assessments were done during the experiment. They concerned growth, production of new leaves, dead and shedding of old leaves, visible symptoms of damage, stomatal conductance and CO2 uptake, chlorophyll fluorescence. The results suggest that the sensitivity to ozone of watered plants is connected to their higher growth ratio and stomatal conductance. Ozone plays a more important role than drought in producing foliar stress conditions

The main aims of the preparatory stands in air pollution areas are growth development, successfull dynamics of the plants and fast creation of the stand microclimate with favourable effect on soil conditions. This process is documented by height and diameter increment. The results confirm different growth dynamics of the particular species. Larch is the species with the best growth dynamics of selected species on experimental plots. On the other hand, beech is the worst species for reforestation in this condition. One of the causes could be damage by frost

The response of Betula pubescens Ehr., B. pendula Roth and two provenances of Pinus sylvestris L. to solar ultraviolet radiation were investigated in a UV exclusion field experiment during the 1997-1999 growing seasons in Finnish Lapland. The seed-grown seedlings were grown under UV-B exclusion and UV-B/UV-A exclusion as compared to control treatment and ambient plants. The only significant impacts of UV exclusion were found in P. sylvestris provenance Enontekio. Longer-term field studies are needed to detect the cumulative characteristics of the UV responses

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

Remarkable differences were found in soil development on three sites. At Modru Dul (the least damaged site) Sopdosols and Inceptisols were found, in Alzbetinska (moderately damaged) Entisols are common, while in Mumlavksa hora (highly damaged) the representative soils are several kind of Podzols, with variable degree of drainage restriction and organic soils. The heavy metal content is always rather low and the vertical distribution does not indicate any appreciable contribution of atmospheric contamination