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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.

Cultivars, homozygous sources and lines of pea (Pisum sativum L.) resistant to Erysiphe pisi had recently been attacked by another powdery mildew species, Erysiphe baeumleri, in the field and in glasshouse conditions. Inoculation with E. baeumleri was carried out in the glasshouse to evaluate the level of resistance of 16 pea genotypes. Susceptible pea lines produced abundant conidia and cleistocarps on petioles and leaves. Only the genotype Tudor (Cebeco 4119) was found to be completely resistant to E. baeumleri. Nineteen pea genotypes (with gene er-1) were tested to natural infection by E. baeumleri in field screening trials. Only few of them demonstrated a high level of resistance (Fallon, AC Melfort and Joel). Consort R, SGL 2024, SGL 1977 and Franklin were very susceptible to E. baeumleri. Cleistocarps with 1-4× dichotomously branching apices of appendages were formed only on susceptible and very susceptible plants of genotypes SGL 444/2185, Consort R, SGL 2024, SGL 1977, LU 390-R2, Lifter, Highlight, Cebeco 1171 and Carneval R in the field and glasshouse. Susceptible control genotypes without gene er-1 (Komet, Adept and Gotik) were attacked in the trials by E. pisi only.

This study was carried out to investigate the effect of treated wastewater on soil chemical and physical properties. Field experiment was conducted in Borkhar region in Isfahan province in central Iran with two water treatments of wastewater and groundwater under sprinkler and surface irrigation systems for three crops of sugar beet, corn and sunflower. Soil samples were collected to 120 cm depth to determine concentration of lead (Pb), manganese (Mn), iron (Fe), cadmium (Cd), nickel (Ni), cobalt (Co), copper (Cu) and zinc (Zn). Irrigation systems had no significant effect on extractable heavy metals in soil. The accumulation of Pb, Mn, Ni and Co in the soil increased significantly in the wastewater treatment as compared to the groundwater treatment. The accumulation of Pb, Mn, Ni, Co, Cu and Zn decreases with the soil depth. Treated wastewater showed no effect on the increase of Fe, Cd, Ni, Cu and Zn during growing season. The irrigation system had a significant effect on infiltration rate, bulk density and total porosity. Under sprinkler irrigation system the infiltration rate increased significantly

The Web of Science database searched results for papers published from the Veterinary Research Institute, Brno, Czech Republic, were analysed. The Veterinary Research Institute has increased publication activity in 2001-2005; more than 4 times in comparison with the period 1990-2004. The impact factor of journals has increased 5.5 times. The collaboration with 31 foreign countries and 175 institutions resulted in the publication of 277 papers in 93 journals during the past five years. Positioning of the Veterinary Research Institute is now among the worldwide leading teams is evident in twelve research profiles. The Web of Science is an efficient tool for record analysis and researcher's and institution's publication activities.

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).

This paper deals with an evaluation of the economics in two commercial plum orchards which were established between 1993-1997 using dense tree-spacing and modern principles of orchard management. This evaluation was conducted in 1994-2004 with the following cultivars: Bluefre, Common Prune, Čačanska lepotica, Čačanska najbolja, Gabrovska, Hamanova, Opal, President, Ruth Gerstetter,Stanley, and Valjevka. Orchard establishment costs, pruning costs, annual orchard operating and pest management costs and returns up to 11 years of growth are given. A denser planting had a positive influence on total yields per hectare with higher returns. Costs per ton of fruit mostly varied between 4 and 7 thousand CZK, whereas farmer prices fluctuated between 7.6 to 13.6 thousand CZK per ton. The highest returns after seven years of growth from one hectare were exhibited by the cultivar President on rootstock St. Julien A in the spacing 4 × 2.5 m followed by the cultivar Stanley on rootstock Myrobalan and the same spacing.

Dokumenty týkajúce sa regulácie hospodárenia v lesoch sa prakticky až dodnes považovali za materiály, týkajúce sa skoro výlučne len jednotlivých odborných rezortov. Na základe Vyhlášky Ministerstva financií SR č. 465/1991 ich možno efektívne využívať aj v rámci rezortov financií a spravodlivosti. Ďalšie významné medzirezortné využitie týchto dokumentov vyplýva zo Zákona č. 127/1994 o posudzovaní environmentálneho dopadu. Cieľom práce je demonštrovať proces posudzovania na konkrétnom príklade - ploche patriacej do lesného pozemkového fondu. Okrem máp, výsledkov pozorovania, slovných popisov a súborov numerických údajov, týkajúcich sa jednotlivých porastov, obsahujú tieto dokumenty aj kódované údaje, ktoré pre väčšinu užívateľov nie sú zrozumiteľné bez využitia dekódovacích kľúčov. A práve tieto posledné údaje majú pri vyhodnocovaní environmentálneho dopadu najvyššiu výpovednú hodnotu. Po nadobudnutí platnosti pripravovaného zákona (vyhlášky) o strate vlastníctva, vyplývajúcej z prohibitívnych a ďalších podmienok v lesnom hospodárstve v súvislosti s presadzovaním verejno-prospešného záujmu (Kundrík et al. 1999), významne vzrastie dôležitosť využitia finálnych dokumentov týkajúcich sa regulácie hospodárenia v lesoch SR.

Norway spruce yellowing and defoliation caused by Mg deficiency was frequently recorded on many sites of the Šumava Mts. (Bohemian Forest Mts.) since 1980's. A forest experiment aimed at investigation response of spruce to Mg application (commercial fertilizer SILVAMIX^® Mg NPK) was set up in 1998. Fertilizer was applied manually in a dose of 96.5 kg Mg/ha in spruce (S) and beech-spruce (BS) vegetation altitudinal zones in spring 2000. Immediate decrease of yellowing was revealed in fertilized plots in both vegetation zones and yellowing almost completely disappeared at the end of the investigation in 2005. Further, fertilization resulted in stabile foliation while marked defoliation was reported from control plots in both vegetation zones. Mg deficiency can be effectively eliminated by appropriate fertilizer application. Balanced nutrition contributes to long-term vigour and stability of forest stands.

The enhanced use of information and communication technologies (ICT) has a strong impact on business-to-business (B2B) and business-to-consumer (B2C) relationships as well as the way the key business processes are conducted. It can save costs and time, enable businesses to reach a wider market and to respond more quickly to the customer demands. These benefits open up new ways of doing international business. The policy objective is to encourage the integration of e-business into normal business by promoting the take-up of e-business services. Information and communication technologies are necessary to be seen as a tool for the increase of prosperity and competitiveness.

In 2001-2005, the effects of game on the condition and development of natural regeneration of a floodplain forest were studied in three permanent transects in the Vrapač National Nature Reserve (NNR). Fraxinus excelsior, Acer pseudoplatanus, Acer campestre and Acer platanoides predominated in the regeneration. The species were markedly damaged by roe deer (Capreolus capreolus) and fallow deer (Dama dama) browsing, the most affected being Acer pseudoplatanus. In spite of always newly occurring trees from self-seeding, the abundance of trees decreased during the studied period, self-seeding did not grow up from a height of 30-40 cm, the proportion of Acer pseudoplatanus decreased and that of Fraxinus excelsior increased. In addition to browsing, in 2003 and 2005 browsing damage to bark was noted in some places and in 2005 also the breaking of trees with subsequent browsing of terminal shoots, the causal agent of both types of damage being fallow deer. The development of natural regeneration is limited in principle by trophic preferences of game and by the tolerance of particular species to repeated damage. On the basis of these conditions it is necessary to consider the present game stock to be contradictory with objectives of area protection and preservation.

Haemophilus parasuis is a common epiphyte of the upper respiratory tract of pigs. The factors of H. parasuis pathogenicity that enable some strains to be virulent and consequently cause a clinical disease have not been established yet. Fifteen serovars of H. parasuis have been described at present. Individual serovars differ in virulence, and considerable differences in virulence also exist within each serovar. Virulent strains can particularly participate as microorganisms secondary to pneumonia, cause septicaemia without polyserositis or Glässer's disease characterized by polyserositis, pericarditis, arthritis and meningitis. Clinical symptoms of this disease are highly variable. Therefore, culture detection of causative agent, particularly from the brain, joints and polyserositis is an essential diagnostic tool. The disease caused by H. parasuis can be treated with antibiotics; however, oral or parenteral administration of very high doses of antibiotics is necessary. The level of animal hygiene and animal husbandry are important factors for prevention of this disease. Commercial or autogenous vaccines can be used in the immunoprophylaxis of pre-parturient sows and their progeny after weaning. For the production of autogenous vaccines, it is most effective to use isolates from animals with lesions present in CNS. Isolates recovered from arthritic and systemic sites of infection are less suitable and isolates recovered from lungs are not suitable at all because of their heterogeneity.

The effect of the length and intensity of feed restriction on carcass quality characteristics was studied in two experiments. In the first experiment rabbits were restricted 1 or 3 weeks. Group 1 was fed ad libitum, group 2 was restricted from 35 to 42 days of age (50 g per day/rabbit), group 3 was restricted from 42 to 49 days of age (65 g per day/rabbit), group 4 was restricted from 56 to 63 days of age (90 g per day/rabbit) and group 5 was restricted three weeks, from 35 to 42 days of age (50 g per day/rabbit), 42 to 49 days of age (65 g per day/rabbit) and from 56 to 63 days of age (90 g per day/rabbit). Rabbits were slaughtered at the age of 84 days. In the second experiment the rabbits were restricted between 42 and 56 days of age and the rabbits were divided into three groups. Group 1 was fed ad libitum, the rabbits in group 2 got 50 g of feed at the age of 42 to 49 days and 65 g of feed at the age of 49 to 56 days and in group 3, 50 g and 75 g of feed in the two periods, respectively. Carcass characteristics were evaluated at the age of 49, 56, 63 and 84 days. Restriction did not affect dressing percentage but reduced the weight of loin. Renal fat was detected in restricted rabbits at the age of 63 days whereas in the ad libitum fed ones at 56 days. Renal fat was significantly (P ≤ 0.05) reduced in rabbits restricted from 56 days of age (experiment 1, 19.71 g, 19.28 g, 26 g vs. 14.33 g and 11.43 g). Kidney and liver weight was influenced by the restriction and realimentation period. The meat colour and pH (measured 24 h post mortem) were not affected by treatments.

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.

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.

The main aim of this article is to evaluate the possibility of forage yield maps creating based on mowing machine's conditioner power input measurement. Strong spatial dependence was observed for conditioner power input data. For the data file from material feed rate measurement the medium spatial dependence was calculated. Relatively low value of variograms range is possible to explain by the type of chosen exponential model. Visual displaying of data distribution is done by the maps. These maps were plotted under kriging method. It is possible to observe distributions of higher and smaller values of conditioner power input and material feed rate measurement by this way. Plotted maps are shown in Figures. The correlation coefficients were calculated 0.419 for filtered data. It follows from this evaluation that conditioner power input measurement can be used for the determination of mowing machine material feed rate.

In case that the climatic or farming conditions have changed in a region, it is possible to anticipate that the core parameters of drainage constructions will not be adequate for the current needs. Some of these constructions might be over-dimensioned, which would be inconsistent with current terms of nature and water resources protection. On the other hand, the valuable contribution the regulation of the water regime of originally waterlogged lands and swamps indisputably brought along and thus enabled the agricultural use of drained lands would be depreciated to a certain extent. In this paper, some scenarios of probable climatic changes in the Czech Republic's territory and the anticipated effect of these changes on the components of the hydrologic water discharge from drained agricultural and forest catchments are studied. The function of drainage systems on selected experimental lands is examined. However, not only probable changes in precipitation, temperature and water runoff should be taken into account, but also changes in the way of farming, i.e. changes in the agricultural conditions and data that played a decisive role in the calculation of the basic parameters of these construction projects, for instance, the spacing of parallel drains or trenches or the depth of their laying. In the Czech Republic about 1.1 million ha of total agricultural land was drained by the end of the twentieth century. In some localities of Eastern and Southern Bohemia up to 80% of agricultural land was drained. To what extent the above-mentioned climatic changes and the changes in the way of farming influence the drainage system and whether adjustments of these systems are required are the questions we tried to answer at least partly in this contribution. The effect of climatic changes on the hydrologic balance and/or on the runoff from the catchments significantly varies up to ± 150% provided that we compare average runoff. The influence of changes in the way of farming on the hydrologic balance manifests itself in a more concrete, but negative way, and that demands a concrete reaction on the part of the water management control. It is therefore vital to take such measures of regulation of the water regime of soil for the existing drainage systems that will ensure both the drainage phase and the phase of runoff retardation. Single-function and obsolete drainage systems should be converted into systems with controlled drainage and irrigation functions - the double-function control systems.

Twenty seven Pasteurella multocida rabbit isolates were characterised by pulsed-field gel electrophoresis (PFGE) generated by restriction endonuclease ApaI, and examined for the presence of capsule and fimbriae, and tested of haemolytic activity and endotoxin release in presence of rabbit plasma. Among the isolates a high number (n = 20) of different PFGE types was observed. All isolates were found to be encapsulated and four of them also possessed fimbriae. Although the presence of the aphA gene, conferring a haemolytic phenotype for Escherichia coli under anaerobic conditions, was indicated in all of the isolates by PCR, clear haemolytic activity was observed in only one isolate when grown anaerobically. All of the isolates grew easily in the presence of rabbit plasma which showed a high capacity to bind the released endotoxin.

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.

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.

This research deals with a comparative study of two different N-saturated forests: 1. beech forest and 2. spruce forest at the same locality of \solling, Central Germany. The present results show that ¹⁵N natural occurrence in the rainfall (both above and below canopy) at Solling site is similar (δ¹⁵N = -15‰ to +19‰) to other sites of the world (such as NITREX sites, USA etc.). Furthermore, ¹⁵N values in the soil water ranged from -4.32 (± 2.09) to +5‰ (± 1.47), which also corresponds to NITREX sites and other sites of Europe and USA. In both forests, δ¹⁵N enrichment of both NH₄-N and NO₃-N showed a decreasing trend of their values from bulk precipitation to the upper soil layer, but increasing in the deeper soil layer again. An increase in the ¹⁵N enrichment of soil water from upper soil depth to lower soil depth was observed in our study and it is assumed to be due to the strong net nitrification taking place in the upper layer (organic surface layer) of soil. The soils at both sites showed characteristic low (negative) δ¹⁵N values in the upper organic layers, strongly increasing to positive δ¹⁵N values in the mineral soil. In the lower depths of mineral soil horizons of both stands, an increase in δ¹⁵N values was found to culminate at +3 to +5‰. In contrast to the mineral soil horizon, in the organic soil horizon (0 to 6 cm depth) of both sites there was almost a similar or slight decrease in δ¹⁵N values with depth. This is attributed to the high nitrification rate in the organic soil horizon, resulting in excessive seepage water NO₃-output at both sites (especially at the spruce site).

In 1999-2001 sulfur and sulfate concentrations were studied in expanded young leaves of rapes of the line variety Lirajet and hybrid variety Pronto at the onset of stem elongation (DC 30), flowering (DC 64) and early maturity (DC 70) in different localities of the Czech Republic. Except the S-deficient site the concentration of total sulfur and sulfates in leaves considerably increased in higher growth stages. A less steep increase in S concentration in leaves was associated with rather humid growing season, especially with April precipitation. Great time variations in sulfur concentrations in leaves signal a possibility of diagnostic misinterpretation of plant analysis without exact definition of growth stage. The shape of trend of variations in S concentration in leaves indicates the S nutritive state of the site and the intensity of upward transport of sulfates with soil moisture in the crop nutrition with sulfur. Good yields of rapeseed were connected with minimum concentration of total sulfur 0.5%, and sulfate sulfur 0.2% in leaf dry matter at DC 30. The proportion of sulfates in total concentration of sulfur in rape leaves ranged from 30 to 60% at the onset of stem extension and it increased in higher phenophases. At flowering, sulfates accounted for 80% and more at sites where sulfate uptake from the soil environment was not problematic. Besides the S-soil test, the results of investigations indicate the importance of CEC value of soil for the preventive diagnosis of S-nutrient state of the site.

From the economic point of view the issue is comprehensive namely for its long-term character. At present, there is little experience in complexly understood economic calculations concerning the effect of climate change on forest management. Therefore a new methodology had to be proposed to solve the assigned task, i.e. to analyse the results of research on the effect of climate change on forest management. The issue is closely related to changes in production characteristics of commercial species, i.e. site quality and species composition or health conditions and rotation period of each species and stand. In this case it concerns with a higher proportion of deciduous species at the expense of conifers, namely spruce. This issue also includes the question of further afforestation of non-forest agricultural land, that means the question of land delimitation between agriculture and forestry.

Seven cultivars of common buckwheat were tested in field trials under two levels of nitrogen fertilisation on two experimental sites during 1998-2000. The aim of the experiments was to evaluate the influence of cultivar, nutrition and year on main technological quality parameters (thousand achenes weight, volume weight, proportion of fractions on sieves 4.5 and 4 mm, proportion of husks and yield of groats). The differences were observed between buckwheat cultivars in all observed parameters of technological value. Nitrogen fertilisation before sowing (50 kg.ha^-1) did not influence any parameter. On the contrary, buckwheat technological value was influenced by sequence weather (particularly rainfalls) during flowering and achenes formation periods (July). The influence of year was manifested especially on development of endosperm and husks of achenes. Better growing conditions on experimental site Uhříněves caused lower values of volume weight, lower proportion of pericarp (husks) and considerably higher proportion of fraction over 4.5 mm.

Like spores of many fungi, conidia of Blumeria graminis, the powdery mildew fungus of cereals, release extracellular material. It is released within seconds where conidial surface projections touch a leaf. This ECM is probably adhesive since centrifugation showed that forces greater than those due to normal wind speeds are needed to displace conidia. Also, ECM release is probably involved in rapid sensing of substratum contact, leading to germ tube emergence close to the contact site. Thus, ECM release apparently confers at least two benefits to pathogen survival.

Water infiltration into the soil profile and runoff losses in arable lands are related to the condition of the top layer. The tillage treatment (included no-till) of the top layer plays a key role in changes of the hydro-physical properties, mainly saturated hydraulic conductivity (K) of the treated layer. This paper is focused on the influence of repeated tillage treatments in the same locality on K in a relatively homogeneous soil profile. The field experimental work was conducted in 1997 and repeated in 2000 after three years of repeated treatments in an experimental field of the Research Institute of Plant Production, Prague on Hapludalfs (US Classification)/Orthic luvisol (FAO). The whole experimental site was divided into four tillage treatment areas (TTA) that were maintained using different tillage treatments. A pressure ring infiltrometer (Matula and Kozáková 1997), mounted on the top of a single iron infiltration ring was used to run infiltration tests. The infiltration during the steady state flow (for a long time) was measured, evaluated and K values were calculated. Matula (2002) summarised the theoretical background for the pressure ring infiltrometer and described the final equations for evaluation of the infiltration test results. The conventional ploughing did not give any significant changes in K values after three years. Reduced till treatment and no-till treatment show a significant decrease in the infiltration rate v(t) after three years. The K value decreased approximately three times for reduced till and six times for no-till treatment. The decrease on this type of soil can cause several negative results from the aspect of surface soil hydrology and agriculture (surface runoff increase, water storage decrease, yield decrease, increase in soil compaction of surface layer, soil erosion increase).

Natural regeneration is an important part of close-to-nature forestry. However, natural regeneration also has either natural or technological limits. Among the most important natural limits are a low sum of precipitation and site type. The study concentrates on Žatec region where the long term average sum of precipitation is only 440-450 mm per year. Dry periods during the vegetation time are quite frequent. The study was conducted on clear cut area, stand edge, shelterwood area and stand interior. The results showed the highest population densities in a shelterwood system, the lowest in the stand interior. On the other hand, the dry seedling biomass is lower for seedlings from shelterwood area than from clear cut area.

The influence of accelerated ageing test (AAT), i.e. of higher temperature and humidity, on the content and composition of phenolic compounds in the grains of five cultivars of wheat (Triticum aestivum L.) was studied in the years 1998 and 1999. Total polyphenols were determined spectrophotometrically by Folin-Ciocalteau's phenolic reagent and free phenolic acids by an HPLC method in control samples and after deterioration treatment (AAT) in the Ebi, Estica, Nela, Samanta and Šárka cultivars. Statistical significance of deterioration treatment, cultivar, cultivation site, and harvest year was proved. Content of total polyphenols increased during deterioration and levels of the individual free phenolic acid changed depending on their structures. Mean contents of total polyphenols varied from 600 to 960 mg/kg of dry matter. The increase caused by the AAT ranged between 0-20%, the greatest mean increase was observed in the cultivar Nela (by 19%). Sinapic acid (as high as 540 mg/kg of dry matter), 3-hydroxy-benzoic acid and 7-hydroxycoumarin were determined as the major phenolic acids and coumarins. A decrease of free phenolic acids containing methoxy groups in their molecules (sinapic and vanillic acids) and an increase of phenolic acids with free hydroxy groups (caffeic and gallic acids) was observed after deterioration treatment. Statistically significant (P ≤ 0.05) effect of AAT on the content of free phenolic acids was observed.

Penile urethral obstruction in cats is a commonly seen clinical manifestation. In cases where there is no response to catheterisation and medical intervention, surgery is needed to provide urination and correct uremia and hyperkalemia. Several surgical techniques have been described. The perineal urethrostomy technique, reported by Wilson and Harrison in 1971, has been used extensively and since then various modifications of this technique have been developed by other researchers. In 2000, Yeh and Chin described a modified perineal urethrostomy tech­nique created by use of the prepuce mucosa. This technique was used in our clinic in 20 cats with penile urethral obstruction. Seventeen cats recovered without complication. A 2.6 mm diameter catheter was placed in each of the 3 cases in which leakage was determined in the anastomosis site. The urine gathered in the site subcutaneously was drained. Normal urination was achieved in 2 of the 3 patients treated with this technique. The remaining case was re-operated and the perineal urethrostomy technique, in which the urethra was sutured to the perineal skin (the Wilson and Harrison method, 1971), was applied. The advantages of this technique over the classical perineal urethrostomy technique are; return to urination shortly after the operation, better urination potential compared to normal cats, a more aesthetic appearance compared to other techniques (similar to a castrated cat), no narrowing of the orifice caused by re-growth of hair. It was also understood that, anastomosis of the urethra and the prepuce mucosa must be carried out with utmost care in order to prevent urine leakage.

This paper deals with natural abundance of ¹⁵N and ¹³C in the soil and needles of the pine forest (Pinus roxburghii, Sargent) along an altitudinal gradient. The study area lies in the elevation range of 1,200 m to 2,200 m in Kathmanduvalley of Nepal. The higher altitude soil was found to be much more depleted of ¹³C than the lower altitude soil. The decreasing trend of C-isotope (as well as the trend of N-isotope) might be attributed to the lower mineralisation rate and net nitrification rate at the higher altitude. The observed differences in isotopic N- and C-contents of needles and soils across altitudinal gradients in this study are a result of the combination of environmentally induced variations in physiological and morphological differences. For example, altitudinal variation in needle δ¹⁵N and δ¹³C at the research site indicates that the needle isotopic composition is related to nitrogen availability at a site.