Effects of thermal-time artificial scarification on the germination dynamics of black locust (<Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> L.) seeds

The aim of this study was to determine the efficiency of methods for the artificial scarification of black locust seeds based on the influence of the air and liquid nitrogen temperatures. Three populations were selected for the analyses: a managed tree stand, a selected seed stand and a seed orchard. Samples of 200 seeds (4 × 50) were randomly selected. Before scarification, the seeds were stored at ?70 °C for 24 h. Nine different scarification treatments were evaluated. To calculate the germination capacity and the dynamics of germination, observations were made on days 3, 5, 7, 10 and 14 after treatment. For statistical analyses, we used repeated measures analysis of variance. The obtained results indicated that the highest scarification efficiency for black locust seeds occurred in the treatment in liquid nitrogen and in an air temperature range of 85–90 °C. The provenance of seeds had a significant effect on the dynamics of germination. Thermal methods and the use of liquid nitrogen can be alternatives to the labour intensive methods of cutting the seeds or using measures that require specialised equipment.     

Theoretical simulation of cutting edge wear when milling wood and wood based products

Theoretical simulation of cutting edge wearing when milling wood and melamine coated particle board based on stochastical and analytical methods is presented. Abrasion, high temperature corrosion (HTC) and frictional wearing effects are discussed. Results of computations show good correlation between the observed and predicted wear rate for three different experiments. Relations between predicted tool wear rate from HTC, content (C _CP) and size (S _CP) of particles of hard mineral contamination and density (D) of cut material is also presented and discussed.     

The variation of tree-ring widths of Scots pine (Pinus sylvestris L.) affected by air pollution

Using eight populations of Scots pine growing in foothills of the Sudetes (southern Poland) as an example, the character and causes of annual ring variation in 1900–1999 were studied. The climate had a short-term effect on radial growth during the whole period investigated. A long-term decrease of radial growth occurred after 1960, but only in some localities. It was probably caused by non-climatic factors, most likely by industrial pollution. The decline of trees during that period is mainly evidenced by a high variation of width of annual rings, a small similarity of chronologies of annual ring widths, and a lack of signal years. After 1990, the tree recovery process was evident. It was most intensive in localities where the earlier stress was the most severe. Then, trees started to produce wide annual rings, homogeneity of the growth reaction increased, and the signal years began to occur.     

Validation of a small-area method for estimating the spatial distribution of the degree of tree damage

This article presents a validation of a method, proposed in Podlaski (2003), for estimating the degree of tree damage. This method belongs to a group of small-area methods. To estimate the degree of tree damage in individual P₃ sub-blocks of the SINUS system of information on the natural environment, a classification based on the degree of defoliation was used. Spatial distribution of the degree of tree damage was estimated through unrestricted simple random sampling. The maximum total estimation error for proportions of fir and beech with a damage degree of zero, and also with second and third degrees jointly, reached a maximum of 35.6% for fir, and 33.8% for beech. P₃ sub-blocks characterised by the highest proportion of the healthiest trees (at least 15% being undamaged trees) occurred in patches in the case of fir, and in larger, compact areas in the case of beech. Because spatial diversification in the health of fir, and to a smaller degree in the case of beech, occurs at small scales, small-area methods for estimating tree condition are necessary. An analogous scheme, combining small-area with large-area methods (utilising sub-blocks of the network of large-area systems in a small-area inventory, and establishing a common database), could be used on a wider scale; for example, by supplementing the program of estimating tree health carried out by the United Nations Economic Commission for Europe (Lorenz et al. 2002) with local inventories.     

A Highly Sensitive Spectrophotometric Method for Gallium Determination with Chrome Azurol S in the Presence of Mixed Cationic-Nonionic Surfactants and its Application in Plant Analysis

A simple and very sensitive spectrophotometric method determining microgram quantities of gallium (Ga) has been developed. The method is based on the complex of Ga(III) with Chrome Azurol S (CAS) in the presence of benzyldodecyldimethylammonium bromide (ST) and polyoxyethylenesorbitan monopalmitate (Tween 40). The complex forms in weakly acid solution (pH 3.8) and shows the absorption maximum at 627 nm. The molar absorptivity (ε) of this system is 1.87 × 10⁵ L mol^?1 cm^?1, and it is clearly higher than ε of other spectrophotometric methods of gallium determination. The detection and quantification limits (LOD, LOQ) are 7.6 × 10^–3 and 0.023 µg mL^?1, respectively. Beer^‘s law is obeyed in the range from 0.02 to 0.60 µg mL^?1 of Ga. The precision and accuracy are good. This first spectrophotometric method of Ga(III) determination in the four-component system has been successfully applied for the analysis of mushrooms and grasses with low content of gallium.     

Influence of redox processes on clay mineral transformation in Retisols in the Carpathian Foothills in Poland. Is a ferrolysis process present?

Purpose

Ferrolysis is a soil-forming process, which involves destruction of clay minerals due to cyclic reduction and oxidation in acidic and periodically wet soils. The main objectives of this study were as follows: (1) to determine the influence of redox processes on clay mineral transformation in Retisols (Albeluvisols) in the Carpathian Foothills in Poland and (2) to verify the occurrence of ferrolysis in Retisols showing various degrees of bleaching.

Materials and methods

Twelve representative soil profiles were selected for analysis. All were formed entirely from loess except for two profiles, in which the lowermost horizons (2C) had developed from weathered flysch rocks residuum. Soil mineral analysis was done using x-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and Mössbauer spectroscopy (MS).

Results and discussion

The obtained results indicate that the qualitative and quantitative mineral compositions of the clay fraction in the E and Eg horizons obtained from Retisols in the Carpathian Foothills exhibiting marked differences in bleaching (strong, moderate, weak, and lack of bleaching) caused by periodic stagnation of water above a slowly permeable fragipan and cyclic redox processes are the same. The E and Eg horizons are characterized by the presence of 2:1 clay minerals with likely organic interlayer fillings, dioctahedral mica, kaolinite, and chlorite.

Conclusions

The results indicate that (1) redox processes occurring in the soils do not affect clay mineral transformation in Retisols of the Carpathian Foothills in Poland and (2) ferrolysis is not the main soil-forming process operating in these soils. This is most likely because iron-bearing minerals are not abundant in the Retisols and/or undergo eluviation to the lower part of the soil profiles. The lower content of the clay fraction in the E and Eg horizons versus that in the lower soil horizons of the Retisols is related to clay illuviation (lessivage), and not to clay decomposition due to ferrolysis.

     

Speciation of Cadmium in the Bottom Sediment of Rybnik Reservoir

Forms of cadmium occurrence in the bottom sediment of a heated water reservoir, polluted substantially with this metal was analysed in the paper. Apart from the analysis mentioned above, a total cadmium content in the bottom sediment and a content of cadmium dissolved in the water of the reservoir was also determined. Dependences between particular forms of cadmium occurrence and its total content in the bottom sediment were analysed. An influence of cadmium content in water on the level of particular cadmium forms in the bottom sediment and an influence of other parameters of the reservoir's water on the content of cadmium in the bottom sediment were also examined.