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This study deals with the assessment of increment losses in Scots pine trees caused by the maturation feeding of pine shoot beetles Tomicus piniperda (L.) and T. minor (Hart.) (Col., Scolytidae) in even-aged stands growing during their entire life span within range of the influence of a sawmill and its timber yard. In spring 2004, on three sample plots, 0.2 ha in size, situated 60, 200, and 500 m from the yard, height and dbh of all trees were measured and increment cores were taken from randomly selected sample trees. An agreement between the spatial distribution of losses in tree increments and the distribution of damage to crowns of investigated stands indicated that the losses resulted from the maturation feeding of pine shoot beetles migrating from the sawmill timber yard. Divergence of growth in the about 25-years-old stand indicated the beginning of intensive feeding of beetles in pine shoots with a high level of probability. In comparison with the control stand the basal area losses in stands growing 60 and 200 m from the beetle source amounted to 57% and 46%, respectively. The difference in the height of trees was as large as almost 100%.

European larch (Larix decidua Mill.) is one of the most important tree species in substitute stands of the Krušné hory Mts. (northern part of the Czech Republic). At present, young larch stands have dynamic height growth and their canopy is closing. Therefore, the proper forest treatment with respect to all functions of these stands is an urgent issue. The aim of the study is to recognise when it is possible to start with thinning and what types of thinning regimes are more suitable in larch stands with respect to their functions as substitute tree species stands. Research was conducted on experimental series Kalek established in a larch monoculture in 1999 (stand age of 12 years) at an elevation of 780 m above sea level in the category Piceeto-Fagetum oligo-mesotrophicum - Calamagrostis villosa. The presented analysis has two main parts: (a) effect of closing canopy on growth of larch - comparison of the groups of trees from border and inside rows and (b) effect of opening canopy on growth and development of young larch stands - comparison of two partial plots (500 m² each): the one without thinning and the other with thinning (negative selection mainly from above at the age of 13 years). Comparative analyses of trees from border and inside rows showed high growth dynamics of these young larch stands, and therefore the first thinning is necessary in this stage (by 15 years of age). In spite of air pollution, the growth of experimental stands is supernormal and exceeds the data from growth tables, but 60% of individuals showed some malformations, mostly one-sided or two-sided stem curvature. Five years after the first thinning we found a significantly lower h/d ratio of mean stem on the thinned plot in comparison with the plot without thinning. On the other hand, the applied thinning had no effect (five years after realisation) on the h/d ratio of dominant trees (200 thickest trees per hectare).

In summit parts of the Orlické hory Mts., massive dieback of forests occurred during an air pollution/ecological disaster in the 70s to the 80s of the 20^th century. Destroyed stands were cut down and deforested areas were planted by more resistant species including mountain pine (Pinus mugo Turra). The aim of the paper was to assess effects of mountain pine on the prosperity of other tree species. Four localities with mountain pine stands were selected at altitudes from 1,000 to 1,115 m. In 2003-2005, growth analyses of shrubs were carried out there and basic parameters of stands were determined such as: height; cover of mountain pine, other tree species and herbs; radiation transmittance and temperature gradients. Results show the importance of the height of mountain pine stands in mitigating climatic changes in the ground layer of air, identification of the light compensation point for the mountain pine prosperity, the dependence of a growth type on outer and inner conditions of mountain pine including partly its age. Under given conditions, the present stands of mountain pine on top parts of the Orlické hory Mts. show their justification because they create a good protection for young seedlings, self-seeding and newly planted tree species. If forest spreads there, the markedly heliophilous mountain pine will recede similarly as in case of more than hundred-year-old mountain pine in the Sowie gory Mts. in Poland.

The article presents original results of research on the humus form dynamics in a semi-natural European beech stand in the National Natural Reserve Voděradské bučiny, in the area of Training Forest Enterprise at Kostelec nad Černými lesy (Czech University of Agriculture inPrague). The accumulation and soil chemical characteristics of particular humus forms were studied: dry matter amount, pH, soil adsorption and exchangeable acidity characteristics as well as plant available and total nutrient contents. The humus form samples were taken in four replications from the particular humus form layers (L, F, H, Ah), and the analyses were performed individually. Samplings were done in the parts of the stand with closed canopy, and they were compared with the state in gaps formed during natural and semi-natural forest regeneration (the stage of stand breaking up left to spontaneous development). The results confirmed marked changes in the quantity and quality of surface humus in the gaps. The amount of dry matter decreased by ca. 25% several years after canopy opening, especially in the H horizon, the pH, base content and base saturation increased, as well as the content of macronutrients (with the exception of total calcium). The results proved considerable changes in the humus forms during the natural and semi-natural forest cycles connected with the stand regeneration.

By means of computer-based image analysis it was possible to accelerate and automate a number of originally time-consuming activities in plant pathology and forest protection. In 1997-2005, image analysis was applied to the measuring of the size of colonies of fungi in vitro, feeding mark area, mass measuring of the size of spores and other microscopic objects, assessment of the progress of rot in a stem etc. The paper brings particular examples of the application of image analysis including methodical procedures and examples of research results obtained using Lucia G and Quick Photo Micro programs.

Green areas and urban forests represent important factors of urbanized environment which attracts more and more attention of forest management and silviculture. Recreational load and its types are the most important driving variable for the management framework in which basic silvicultural methods should be applied. The problem of the required combination of natural and social limits is resolved by a matrix which takes into account forest ecosystem quality and recreation. The matrix defines 9 or 27 units (their number depends on the fact if we take into account the age of stand or not) for which basic management rules could be prepared. The basic rules concerning biological aspects are described in a general way in the article.

Frost cracks which originated in birch due to bending during long-term icing in winter 1995/1996 became the place of entrance for the attack of birch stems by Piptoporus betulinus (Bull. ex Fr.) Karst. and subsequently for one of the causes of birch stand disintegration in the Krušné hory Mts. The hypothesis is substantiated on the basis of regularities of the frost crack dispersion in the stem profile, frequency of occurrence related to the stand age, altitude and cardinal points. The number of frost cracks increased with the transect profile altitude 700-850 m. One crack on the birch stem predominated (73%) while the higher number of frost cracks occurred at altitudes > 800 m. In stands younger than 20 years, frost crack damage was higher (34-47%) than in older stands (14%). Frost cracks occurred in the lower part of stems with the highest bending stress.

Forestreclamation of spoil banks in mining areas in the North-West of the country started in the second half of the last century. Nowadays forest stands growing on anthropogenic substrates which are still unlike to forest soils, are getting in the phase of possible natural and/or artificial regeneration. The basic characteristics of substrate in the area and ecological attitude of used tree species are driving variables for successful regenerations. The study summarizes the vitality and growth of selected species on anthropogenic substrates in the area with the recommendations of key tree species used for forest reclamation. The results show the best adaptation to anthropogenic substrates for black alder and maple.

This paper presents detailed data on the biomass and element pools of six sample trees in the catchments of Plešné andČertovoLakes. Diameters and heights of the sample trees ranged from 28.0 to 63.7 cm and from 14.1 to 38.7 m. The age of the sample trees ranged from 84 to 177 years. Total biomass of the sample trees was in the range of 239.4 kg to 2,932.3 kg. Variation of total biomass between the sample trees was a consequence of the tree biometric data (height and dbh) and age differences. The proportion of stem wood and bark ranged from 63.5 to 69.5%, and from 4.6 to 7.2%, respectively. The proportion of foliage and fine branches ranged from 4.3 to 8.4%, and from 0.7 to 1.9%, respectively. The proportion of branch wood and bark ranged from 2.2 to 6.5%, and from 0.8 to 2.2%, respectively. Mean concentrations of C in different tree components were quite similar. Except C and compared to the other elements, N had the highest mean concentrations in tree components in all cases. Concentrations of P, Ca, Mg, and K showed similar patterns. Generally the highest concentrations of these elements were found in foliage, fine branches, fine roots and bark of stem and branches. Fe, Na, Al and Mn showed the lowest mean concentrations in tree components for all the analyzed elements. The total element pools per tree were highly variable because of the differences in total biomass between the individual trees. Generally, stem wood and bark, foliage, and roots contained the highest proportion of the elements. But there were differences between individual elements. Concerning the important nutrients, while the highest proportion of Ca and Mg was contained in stem wood and bark, the highest proportion of P was contained in foliage. The foliage contained a relatively high proportion of P and K, but a relatively low proportion of Ca and Mg.

The abundance and species spectrum of cockchafers of the genus Melolontha and characteristics of the tribes in four forest regions of theCzechRepublic was explored. We used light traps, automatic meteorological stations and field investigations to study the course of swarming, species composition, abundance of the respective tribes, sex ratio during swarming and the dependence of swarming on the average daily temperature. Studies will continue in the next years and the objective is to use the results for prognosis of the occurrence of cockchafers and the damages subsequently caused by grubs in forest cultures.

The health condition of the population of elms in the region of southern Bohemiawas studied from the viewpoint of their decline, the occurrence of Dutch Elm Disease (DED) and the presence of other diseases. Of the total number of 105 elms in total 33 of them were without any symptoms of the disease or other damage. Elms regenerated quite spontaneously in the neighbourhood of mother trees and their increasing population in mixed forests is hopeful. According to macroscopic symptoms, DED was identified in 10 trees but the presence of pathogens Ophiostoma ulmi and Ophiostoma novo-ulmi was not identified in isolations. A possible reason of this observation is overgrowing the colonies by the Phomopsis oblonga mycelium. This fungus was identified in most isolations. Thus, its role requires further research.

This paper deals with transformation of pure even-aged forest stands to uneven-aged irregular stands on an example of the Klokočná Forest Range. The fully operational management system according to principles of shelterwood or selection systems has been executed here since 1993. An investigation of this transformation process started in 1999 and it is focused on the places with more distinct structural differences. On the basis of research analysis, it is possible to consider about the permanent uneven-aged forest stands in future here. But for successful achievement of this goal it is necessary to continue this transformation step by step for a long time. The transformation is still at the beginning and its result depends on the effort and the forest management goal and the priority of the particular forest functions.

Damage to forest stands and their decline in the Czech Republic evoked a necessity to elucidate the function of soil in these processes. Main factors affecting acidification of forest soils are assessed in the paper. On the one hand, it refers to natural factors such as properties of soil-forming substrates and species composition of forest stands, on the other hand, to the effects of anthropogenic character such as influences of man-made spruce monocultures and effects of acid depositions. Special attention is paid to the development of forest soils in the Krušné hory Mts., where the effects of acid depositions are highest.

Results obtained during 14 years of the experiment are presented. Extreme site conditions are determined by: 8^th vegetation altitudinal zone, podzolic soil and hard climate - average annual temperature 4°C, average annual precipitation around 1,200 mm. Effects of surface experimental liming were studied on immission clear-cuts in long time period, study area is located on the Velká Deštná locality on the main Orlické hory Mts. range. Research plots were established and the basic survey was done in spring of 1988, studies of liming effects were performed in the period 1987-2002. On particular plots, 0, 1,308, 2,826, 3,924 and 8,478 kg/ha of fine limestone (grain size under 1 mm) was distributed by hands on the soil surface, as an application of 3 and 9 t/ha of "fine" and "coarse" material (together 5 variants including the control one). Results are available for the forestry practice, research has to continue in the future - potential of negative liming impacts is topical here, consisting in humus mineralization and nutrients losses. Maximum effects on the soil reaction were observed in 8-10 years after limestone application at the soil surface (F - horizon) and in the period 10-15 years lower (H, A - horizons). Base saturation dynamics shows the time delay 2-4 years following pH values. For the site protection, efficient forest stands are vitally important of pioneer as well as climax species.

In a 6 years' field experiment in a podzolized heather area in Norway the effects of liming and P and Cu fertilization were tested versus changes in vegetation and soil chemistry. The vegetation altered slowly, particularly the woody species, but pronounced over years. Liming had a positive effect on all species except Deschampsia flexuosa and Vaccinium myrtillus, P tended to favour all except V. myrtillus, and Cu promoted all except Nardus stricta, V. oliginosum and V. myrtillus. Surface spreading of liming material and fertilizers caused distinct lime, phosphorus and copper effects and interactions in the soil litter layer. Liming markedly increased pH and Ca level and stimulated microbial activity, whilst the fertilizers increased P and Cu availability in soil. Cu fertilization counteracted a feared Cu deficiency when liming marginal soils. Gradually the changes penetrated into deeper soil layers. This strong chemical influence led the podzol into a cambisol cycle, characterized by retention of humus in the E layer, accompanied by a slight increase in pH, elevated levels of Kjeldahl-N, AL dissolved and exchangeable Ca, and in CEC and BS.

Soil acidification processes are the main factor influencing the distribution of different Al forms in forest soils. The intensity of these processes is given by different stand conditions and anthropic activity. This paper describes the influence of four selected stand factors on the distribution of basic soil characteristics and two Al forms in forest soils of the Jizerské hory Mts. Altitude, liming, soil type and forest cover type are studied as selected factors. Distribution of most soil characteristics in the organic horizon, including organically bound Al, is influenced by the altitude. Distribution of mobile Al form is mainly influenced by liming. In the mineral horizon, no decisive factor affecting the distribution of variables was found. Cartograms of spatial distribution of pH, mobile Al form and total Ca content documenting their spatial relationships are shown.

The bacterium Pseudomonas savastanoi pv. nerii was identified as the causal agent of parenchymatous galls on leaves of potted oleander plants grown at Brno, Moravia, in 2004. The plants had originated from cuttings made from firm shoots of a supposedly asymptomatic plant grown in and introduced from the Mediterranean region. The Biolog GN microplate system was used to identify the isolated bacterial strains. Successful inoculation of Nerium oleander seedlings proved the pathogenicity of the isolates. This is the first record of P. savastanoi pv. nerii in the Czech Republic. :

The acute and chronic toxicity to honeybees, Apis mellifera of water guttation and dew collected from winter rape plants treated with the insecticide Nurelle D^® (a.i. chlorpyriphos + cypermethrin) was investigated. Caged bees were fed on sugar syrup containing water guttation and dew for 24 h (acute toxicity test) and for 10 days (chronic toxicity test). Bee mortality and food consumption were determined daily. A contact toxicity test was performed within 24 h on bees kept in Petri dishes (10 bees per dish) lined with filter paper saturated with the test solution. The acute Nurelle D^® contact and oral toxicity tests showed that the mortality of bees treated with water guttation and dew collected from the treated plants did not exceed 10%. A chronic toxicity test showed that adding contaminated water guttation and dew to the syrup caused an insignificant increase in bee mortality and reduced the syrup consumption significantly. The chlorpyriphos residue found in contaminated water guttation and dew were below the limit of detection (0.8 µg/kg) and the cypermethrin residue was below the detection levels.

A total of 199 Phytophthora infestans isolates were obtained from leaves, tubers and fruits of infected crops of potato and tomato in different regions of the Czech Republic in 2003, 2004 and 2005. They were analysed for mating type using the conventional pairing assay and PCR markers; 107 isolates were of A1 and 92 of A2 mating type. No self-fertile isolate was found. Our study is the first report of the presence and distribution of the A2 mating type of P. infestans in the Czech Republic. The co-existence of the two mating types may enable the pathogen to reproduce sexually, thus enhancing the diversity of its population countrywide.

Molecular and immunological methods were applied for detecting the Ganoderma disease of coconut. Polyclonal antibodies (PAbs) raised against basidiocarp protein of Ganoderma were used. For the polymerase chain reaction (PCR) tests, the primer generated from the internal transcribed spacer region one (ITS 1) of ribosomal DNA gene of Ganoderma, which produced a PCR product of 167 bp in size, was used. Apparently healthy palms in two coconut gardens were tested for Ganoderma disease by ELISA test using basidiocarp protein antiserum. Field trials were laid out in these early-diagnosed palms for the management of the disease. Based on the ELISA results, Pseudomonas fluorescens + Trichoderma viride with chitin amended treatments arrested the multiplication of the pathogen and within 6 months showed an optical density (OD) below the level of infected plants. Integrated Disease Management (IDM) and fungicide tridemorph treated palms showed OD values below infection level within 7 months, and T. harzianum and P. fluorescens + T. viride treated palms showed OD values below infection level in 8 months.

In 1995-1997, the population dynamics of the flea beetles Chaetocnema tibialis and Phyllotreta vittula, associated with Amaranthus retroflexus (wild species) and Amaranthus caudatus (cultivated species), were studied at the locality Nitra-Malanta (48°19'N, 18°09'E) in south-western Slovakia. On both plant species, the number of C. tibialis adults was usually very low until the beginning of July. During July the number of C. tibialis increased, but sooner on cultivated amaranth. An increased number of C. tibialis adults was observed on both amaranth species until the middle of September. The results showed that amaranth plants are a very important reservoir of C. tibialis during summer. P. vittula was a common flea beetle on amaranth during the whole summer, but its numbers never exceeded more than 10 adults per 25 plants. Low temperatures in winter had a negative effect on populations of C. tibialis on both amaranth species and also on populations of P. vittula on A. retroflexus. The lower the precipitation was in July, the higher were the populations of C. tibialis on both amaranth species and the populations of P. vittula on A. retroflexus.

The set of 102 samples of agricultural soils was taken for the study of the load of agricultural soils with polychlorinated dibenzo-p-dioxins and dibenzofuranes (PCDDs/Fs). The background value of PCDDs/Fs in agricultural soils of theCzech Republicwas determined. The soils with different sources of the load of PCDDs/Fs were compared. It was concluded that fluvisols in fluvial zones and soils with long-term sludge application are soils with the highest contents of PCDDs/Fs. The soils affected by imission outputs show a lower intensity of the load with PCDDs/Fs that is characterised by higher content of toxic congeners.

Cadmium mobility in sewage sludge amended by four types of ameliorative materials (lime, limestone, bentonite and zeolite) incubated under aerobic and anaerobic conditions for eight months was studied in the experiment. The most statistically significant decrease of available Cd extracted by 0.01 mol/l CaCl₂ was recorded in sludge between second and fourth months of incubation. As most effective stabilizers were found limestone and bentonite added into the sludge incubated under aerobic and anaerobic conditions respectively. The presence of air reduced Cd mobility in individual sludges more than lack of air. Cadmium was separated by sequential extraction into five fractions as water soluble, exchangeable, bound with Fe and Mn oxides, organically bound, and residual fraction. Sequential analysis showed decrease of Cd in exchangeable and oxide fractions in sludge treated by lime and limestone at the end of aerobic incubation. Cadmium was found in water soluble and exchangeable fractions in small portion, even so its content in these fractions was higher than determined in slighter 0.01 mol/l CaCl₂ solution.

The growth and yield response of spring wheat to inoculation with foreign and local rhizobacteria of Erzurum (Turkey) origin was studied. At the first stage of the research, a greenhouse experiment was carried out with wheat cv. Kirik using 75 local bacterial strains isolated from the soil with 6 foreign bacteria, and a control. According to results of the greenhouse experiment 9 local strains were identified. At the second stage, the response of wheat cv. Kirik to 20 treatments (9 local strains, 6 foreign bacteria, 4 levels of N, and a control) was investigated in Erzurum field conditions. Seventeen strains had significant positive effects on tiller number per plant, 47 strains on plant height, one strain on dry matter yield, and 28 strains on plant protein content in the greenhouse experiment. Inoculation with certain rhizobacteria clearly benefited growth and increased the grain and N-yield of field grown wheat. The effects of local strains were observed to be in general superior to those of foreign strains. Inoculation with the local Strain No. 19, 73, and 82 increased total biomass by 18.7, 18.1, and 19.9%; grain yield by 18.6, 17.7, and 18.0%; total N-yield by 27.5, 24.3 and 26.0%, respectively, as compared to control. In conclusion, Strain No. 19, 73, and 82 can be a suitable biofertilizer for spring wheat cultivation in areas with similar conditions as in Erzurum. Inoculation with these strains may lead both to increases in wheat yield and savings of nitrogen fertilizer.

The effect of osmotic stress on oxidative injury, compatible solutes content and water relations was investigated in two maize cultivars (Zea mays L. cv. Ankora - drought-sensitive and cv. Nova - drought-tolerant). Relative water content in leaves of both cultivars decreased after drought treatment, leaf water loss of sensitive cv. Ankora was higher than that of cv. Nova. The 24 h water stress induced by 0.3M sorbitol (-1.4 MPa) resulted in a damage of cell membranes. Lipid peroxidation rose in all studied organs of cv. Ankora and electrolyte leakage in roots of cv. Ankora was much higher than in cv. Nova. Similarly, proline content increased significantly in all studied organs of cv. Ankora. Content of soluble sugars increased in all studied organs of both cultivars, but the mesocotyl of cv. Nova accumulated the highest amount of sugars. The electrolyte leakage was the highest in the roots of both cultivars. Osmotic stress had deep influence predominantly on the roots of both cultivars. It is apparent that stress impact on the drought-sensitive cv. Ankora was deeper than on the drought-tolerant cv. Nova.

Soil organic carbon (SOC) is the most often reported attribute and is chosen as the most important indicator of soil quality and agricultural sustainability. In this review, we summarized how cultivation, crop rotation, residue and tillage management, fertilization and monoculture affect soil quality, soil organic matter (SOM) and carbon transformation. The results confirm that SOM is not only a source of carbon but also a sink for carbon sequestration. Cultivation and tillage can reduce soil SOC content and lead to soil deterioration. Tillage practices have a major effect on distribution of C and N, and the rates of organic matter decomposition and N mineralization. Proper adoption of crop rotation can increase or maintain the quantity and quality of soil organic matter, and improve soil chemical and physical properties. Adequate application of fertilizers combined with farmyard manure could increase soil nutrients, and SOC content. Manure or crop residue alone may not be adequate to maintain SOC levels. Crop types influence SOC and soil function in continuous monoculture systems. SOC can be best preserved by rotation with reduced tillage frequency and with additions of chemical fertilizers and manure. Knowledge and assessment of changes (positive or negative) in SOC status with time is still needed to evaluate the impact of different management practices.

This study compares effects of 2,3,5-triiodobenzoic acid (TIBA) and flavonoid quercetine (Q). In spite of the fact that both these compounds are inhibitors of the polar transport of auxin, a number of experiments demonstrated that their properties are different. If the flax seedlings were decapitated and one cotyledon was removed, the axillary bud of the remaining cotyledon grew up more intensively while TIBA (0.5% applied in the form of a lanolin paste on the remaining cotyledon) induced a correlative reversal so that axillars of removed cotyledons grew up more intensively. However, when Q (0.5%) was applied on the remaining cotyledon in the form of a lanolin paste, this inhibition was not significant. In the lamina-deprived petioles of apple trees TIBA accelerated abscission while Q caused an inhibiting effect similar to that of auxin. TIBA applied on epicotyls of pea seedlings inhibited their growth by 35% while Q only by 15%. As far as the release of ethylene by pea seedlings is concerned, both compounds showed promoting effects similar to the effect of auxin.