Search

Since 1994, the nutritional status and the air pollution load have been evaluated on 20 research plots, located in young Norway spruce stands in the ridge area of the Krušné hory Mts. The most recent acute damage to the spruce stands, in the winter of 1995/96, was connected with a long-lasting inversion situation in the eastern area of the Krušné hory Mts. Today, the health status of the spruce stands, expressed in terms of the crown defoliation, has recovered and is comparable to that found in other regions of the Czech Republic. The sulphur and fluorine content of the needles has decreased significantly. The long-term negative effect of acid deposition that contributes to the degradation of forest soils remains an important part of stressors acting on forest ecosystems in the region. In recent years, nitrogen and sulphur concentrations in the needles have increased slightly again. A long-term tendency towards a decrease in the phosphorus, calcium and potassium content of the needles was detected.

We documented the current typological and phytosociological characterisation of the ground vegetation as an essential component of biodiversity in 154 Czech forest monitoring plots and to describe its changes during the past 15 years in regard to the deposition and concentration of nitrogen in the soil. Plots were classified as vegetation units in accordance with the UNECE and FAO nomenclature and on the basis of their potential natural vegetation and compared in terms of the occurrence and coverage of the indicative selected nitrophilous species. In all the soil horizons tested statistically significant differences in the C/N ratio were observed between areas with and without the presence of certain selected nitrophilous species (Geranium robertianum, Impatiens parviflora, Sambucus nigra, Urtica dioica). In the areas with the presence of the Geranium robertianum and Urtica dioica species, statistically significantly higher concentrations of nitrogen were recorded in some soil horizons than in those areas with the absence of these species. The findings concerning the influence of nitrogen on nitrophilous herbaceous indicators were compared with the European results obtained in the framework of the ICP Forests international programme and with those of other foreign studies.

In the second half of 20th century silver fir regeneration has been observed throughout all of the Europe, including the Czech Republic. The Bohemian Forest - Šumava Mts. is one of the regions where the silver fir percentage in forest stands is supposed to be increased from the present 2% to nearly 12%. During the period 2006-2007, in the Czech part of the Bohemian Forest, samples of silver fir were taken mainly in the upper altitudinal limit of silver fir occurrence. In the present paper the results of performed analyses are compared with similar surveys conducted in the other European regions. Samples from the Bohemian Forest, in contrast to other results, differ in higher phosphorus content and lower contents of calcium and manganese. Nitrogen content is slightly higher. Our values for the other elements (magnesium, potassium, zinc, sulphur) are comparable to those reported in Poland and Slovakia. In Germany, aside from the above mentioned differences, higher magnesium content was also found within the locality sampled.

Surface ozone is considered to be a very phytotoxic gaseous air pollutant. Its negative impacts at both the cell and the organ level have been shown, mainly as a result of experiments. However, the demonstration of ozone negative impacts on native plants is not explicit. An assessment of ozone impact on vegetation and ecosystems using indicators based on ambient ozone concentrations is insufficient and assessment techniques based on internal ozone dose and on real plant damage are more appropriate. Such a possible technique is the mapping of ozone visible symptoms due to ozone influence. The ICP-Forest method concerning ozone visible symptoms and the assessment of ozone influence were applied for the purposes of this case study. The visible symptoms are characterized by a few typical signs. Nevertheless, the identification of visible symptoms in native conditions can be problematic and misleading conclusions could be drawn. Therefore it is necessary to complete the identification of visible symptoms with a validation in order to confirm ozone as the cause of plant injury.

In recent years, the Czech part of the Silesian Beskids has been affected by strong yellowing of Norway spruce stands and gradual decline of individual trees. Similar damage has also been observed in the neighbouring parts of Poland and Slovakia. The article presents the results of an investigation in the Forest District Jablunkov - part Nýdek. To evaluate the situation, monitoring plots were established and a regional survey was carried out together with tree-ring analysis. The results show a mosaic distribution of damage in the region studied, independent of the altitude and forest type. Defoliation was lower in 20-40 years old stands. Even these young classes, however, show yellowing symptoms. The decline of stands started to be visible at the end of the 1990s; significant loss of vitality was observed in the most affected stands in 2003, after an extremely hot and dry vegetation period. Actual development of meteorological conditions plays an important role in the stand damage. Lastly, possible causes of damage and further development are discussed.

Concentrations of air pollutants measured by passive samplers, atmospheric deposition to forest ecosystems, soil water chemistry, nutrient content in the soil and foliage were all measured within a study of the causes of forest decline in Nýdek Forest Range, Jablunkov Forest District (Silesian Beskids). Declining Norway spruce stands are situated in a region of historically high air pollution load, mainly from the Třinec and Ostrava agglomeration. Air pollution significantly decreased in the second half of the 1990s. Forest soils showing the insufficiency of main nutrients remain today as the main factor affecting the forest vitality. The situation in the soil is subsequently reflected in the nutrition level of the assimilation tissues. Simultaneous effects of other stressors (e.g. biotic, meteorological ones) can support a sudden worsening of the stand health and cause serious damage.

In May 31, 2000, the Government of the Czech Republic, has adopted the Decision No. 532, assigning the minister of agriculture to realize liming and fertilizing in the Krušné hory Mts. and Orlické hory Mts. Based on the decision, in 2000-2003, liming of forest stands was done, at the area of 34,000 ha. Changes of soil and leaf chemistry two years after liming were studied in the Western Krušné hory Mts., Forest administration Horní Blatná. Slight pH increase layer was stated both in the humus layer, and in upper horizons of mineral soil. Increased contents of calcium and magnesium, same as nitrogen and potassium were also recorded. Content of basic cations, mainly of magnesium and calcium, in the sorption complex was increased, aluminium content was decreased. C/N ratio in the humus layer did not change, ratio of basic cations and aluminium in the humus layer was increased significantly. Analyses of the assimilation organs of spruce have proved increase of magnesium and calcium content. The increase was higher in the stands of originally lower values of these elements. While before liming, in about a half of the samples of second needle year class, magnesium was under the deficiency level, two years after liming no deficient values were recorded.