Litterfall is a major, yet poorly studied, process within forest ecosystems globally. It is important for carbon dynamics, edaphic communities, and maintaining site fertility. Reliable information on the carbon and nutrient input from litterfall, provided by litter traps, is relevant to a wide audience including policy makers and soil scientists. We used litterfall observations of 320 plots from the pan‐European forest monitoring network of the “International Co‐operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests” to quantify litterfall fluxes. Eight litterfall models were evaluated (four using climate information and four using biomass abundance). We scaled up our results to the total European forest area and quantified the contribution of litterfall to the forest carbon cycle using net primary production aggregated by bioregions (north, central, and south) and by forest types (conifers and broadleaves). The 1,604 analyzed annual litterfall observations indicated an average carbon input of 224 g C · m−2 · year−1 (annual nutrient inputs 4.49 g N, 0.32 g P, and 1.05 g K · m−2), representing a substantial percentage of net primary production from 36% in north Europe to 32% in central Europe. The annual turnover of carbon and nutrient in broadleaf canopies was larger than for conifers. The evaluated models provide large‐scale litterfall predictions with a bias less than 10%. Each year litterfall in European forests transfers 351 Tg C, 8.2 Tg N, 0.6 Tg P, and 1.9 Tg K to the forest floor. The performance of litterfall models may be improved by including foliage biomass and proxies for forest management.

The article evaluates changes in the forest health status and nutrition, caused by the historical development of the air pollution load, in the Norway spruce (Picea abies L. Karst) stands in the Jizera Mts. The Jizera Mts. are located in northern Bohemia, on the border between the Czech Republic and Poland close to western Saxony (Zittau). The 19 research plots selected on the plateau within the forest sites of the young Norway spruce stands were installed in 1991. Since 1993 the defoliation of the tree crown has been assessed every year; sampling of needles for nutrient analyses has also been undertaken annually. Soil samples were taken in 1995, 1999, 2003 and 2009. Long-term investigation confirmed that the health condition of the trees, evidenced by crown defoliation, is influenced by a combination of various stress factors. To define the relationship between the crown defoliation, nutrients and stress element contents, a linear regression model was proposed. The model for the current year needles demonstrates that the defoliation of the spruce crowns in the Jizera Mts. is a function of the nitrogen, phosphorus, potassium, magnesium sulphur and fluorine concentration. The crown defoliation of the spruce stands is increasing with the decrease in the nitrogen and magnesium concentrations and the increase in the sulphur and fluorine concentrations in the needles. The unbalanced nutrition in the Jizera Mts. is affected by the ongoing nitrogen deposition to the forest ecosystem. This is manifested as a disturbed N:P and N:Mg ratios in the needles. Acidification of the soil environment and the phosphorus and magnesium deficiency may be limiting factors to the forest's nutrition in the future. The optimal range of N:Mg ratio (8-30) is relatively wide for the Jizera Mts. The upper optimal limit for the young spruce stands in the Jizera Mts. should be decreased to 25. The comparison of the element concentration in the needles and mineral soil confirmed the nutritional threat and the deterioration in the condition of the spruce stands in the Jizera Mts.

ABSTRACT: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.

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.

AbstRACt:In the second half of 20 th 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.

No abstract

No abstract

No abstract