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Coarse woody debris (CWD) is an important structural and functional component in forests in Northern Iran. In this study we determine the temporal patterns of CWD in Kheyroud Forests by examining the CWD volume in different decay classes and size classes along a chronosequence of secondary forest succession. The volume of CWD followed the general "U-shaped" temporal trend: the highest in the late successional forest (51.25 m³.ha^-1), lowest in the middle successional forest (25.95 m³.ha^-1) and intermediate in the early successional forest (37.05 m³.ha^-1). The late successional forest had a larger amount of logs, snags and stumps than the other two forests. In contrast, the snag volume did not differ between the late and middle successional forest. CWD in decay classes III and V was greater in the late successional forest than that in the other two forests, while CWD in decay classes II and I did not differ among the three successional forests. CWD in class II and I was significantly higher in the early successional forest than that in the middle successional forest. In the early and middle successional forests, CWD in early decay class was dominated by Carpinus betulus L. followed by Fagus orientalis Lipsky. In the late successional forest, CWD in early decay class was dominated by Fagus orientalis while CWD in the late decay class was dominated by Carpinus betulus. While forest succession had a large influence on the amount of CWD in different decay classes, it had no effect on CWD distribution among the different size classes. Our results suggest that both anthropogenic and natural disturbances have had a long-term effect on the distribution of CWD among three forests.

The Lusatian lignite-mining district (Eastern Germany) is characterized by a high share of marginal post-mining areas. At these sites, crop yield is generally low, and hence, conventional land use systems often fail in terms of reliable and efficient crop production. In this paper the attempt is made to evaluate the production of woody biomass for bioenergy in short rotation coppices (SRC) and alley cropping systems (ACS) with black locust (Robinia pseudoacacia L.) and lucerne (Medicago sativa L.) from the aspect of possible ecological and economic benefits compared to the conventional agricultural recultivation practice. The results show that, due to both high establishment and harvesting costs and comparatively low prices of energy wood, land use systems such as SRC or ACS are currently hardly profitable compared to conventional agriculture. However, the cultivation of black locust resulted in a higher humus accumulation and in a lower harvest-related nutrient export than the cultivation of lucerne as a typical recultivation crop in this region. Therefore, it can be concluded that for an improvement of soil fertility woody biomass production is more beneficial than the conventional agricultural recultivation practice.

Analyses of root mycorrhizal samples and monitoring of fruiting bodies of macromycetes from Norway spruce stands at mountain and foothill localities in the Krkonoše and Orlické Mts. provided several data series allowing to assess and compare (albeit somewhat preliminarily) mycorrhizal conditions and macromycete incidence related to stand ages and location conditions. The overall mycorrhizal conditions in young (10 years old) and older (80 years old) stands on formerly agricultural soils are comparable to those in 80- and 90-year-old forests growing on standard forest soils, but young spruce stands in the Orlické Mts. replanted on forest soils do not surprisingly show any favourable mycorrhizal characteristics. The research documents a marked diversity of macromycete species composition in mountain spruce stands compared to foothill spruce stands on former agricultural soils. While in the younger mountain spruce stands of the Orlické Mts. the expansion of macromycete species composition began to develop in a similar fashion to that in the Krkonoše Mts., the comparison of older (80-year-old) stands on formerly agricultural soils in the Orlické Mts. foothills and Krkonoše Mts. implies that the macromycete species composition developed quite differently but with a similar success.

Comprehensive analyses of soil properties of sites of native Scandinavian broadleaved tree species were performed in 36 habitats in East Norway. The material consisted of stands of silver birch (Betula pendula Roth.), white birch (Betula pubescens Ehrh.), black alder (Alnus glutinosa Gaertn.), speckled alder (Alnus incana Moench.), European ash (Fraxinus excelsior L.), pedunculate oak (Quercus robur L.) and sessile oak (Quercus petraea [Matt.] Liebl.). The main objective was to describe the vertical characteristics and variations in some selected soil variables of the soil profiles. Particular soil horizons of 15 Brunisolic soils, 11 Regosolic soils, 6 Gleysolic and 4 Podzolic were sampled and analyzed for soil texture, bulk density, specific density, porosity, oxidizable carbon, total nitrogen content, pH in water, exchangeable acidity, exchangeable cations and anions (Mg, Ca, Mn, Al, S, Fe, B, P and K), cation exchange capacity and base saturation. No regular patterns were found in selected soil properties when tested between various soil units in silver birch stands. Furthermore, silver birch stands were found on sites, which topsoil (i) significantly differed in their cation exchange capacities, (ii) did not differ significantly in their pH values, and (iii) mostly differed in their clay contents and (iv) mostly did not differ in BS. Differences among the Humic Regosols, Luvic Gleysols, Sombric Brunisols, Eutric Brunisols and Humo-Ferric Podzols for silver birch stands in their topmost horizons of humified organic matter intimately mixed with the mineral fraction horizons and differences among particular soil horizons for the main soil properties under all the selected broadleaved tree species stands are discussed.

Changbai Mountain Natural Reserve (1,985 km² and 2,734 m a.s.l.) of Northeast China is a typical ecosystem representing the temperate biosphere. The vegetation is vertically divided into 4 dominant zones: broadleaved Korean pine forest (annual temperature 2.32°C, annual precipitation 703.62 mm), dark coniferous forest (annual temperature -1.78°C, annual precipitation 933.67 mm), Erman's birch forest (annual temperature -2.80°C, annual precipitation 1,002.09 mm) and Alpine tundra (annual temperature -3.82°C, annual precipitation 1,075.53 mm). Studies of soil carbon (C) and nitrogen (N) mineralization have attracted wide attention in the context of global climate change. Based on the data of a 42-day laboratory incubation experiment, this paper investigated the relationship between soil moisture and mineralization of C and N in soils with different vegetation types on the northern slope of the Natural Reserve Zone of Changbai Mountain. The elevation influence on soil C and N mineralization was also discussed. The results indicated that for the given vegetation type of Changbai Mountain the C and N mineralization rate, potential mineralizable C (C0) and potential rate of initial C mineralization (C₀k) all increased as the soil moisture rose. The elevation or vegetation type partially affected the soil C and N mineralization but without a clear pattern. The moisture-elevation interaction significantly affected soil C and NO₃^--N mineralization, but the effect on NH₄⁺-N mineralization was not significant. The complex mechanism of their impact on the soil C and N mineralization of Changbai Mountain remains to be studied further based on data of field measurements in the future.

Runoff generation under various natural conditions has often been studied in forested watersheds for a long time. In 1967, Hewlett designed a variable source area model. The model is based on the expansion and shrinkage of variable source areas and consequent changes in a drainage network during a discharge event. The runoff investigation was carried out in a forested watershed situated in the summit area of the Orlické hory Mts. The watershed has a drainage area of 32.6 ha with the land-surface elevation ranging from 880 to 940 m a.s.l. Runoff components, their amounts and ratios were calculated using a simple graphical-mathematical method of the hydrograph recession limb analysis according to a reservoir model representing the particular components (base flow, subsurface flow and overland flow, in other words slow, accelerated and rapid flows). Comparing the amount of slow and rapid runoff constituents (89.5-99.4% and 0.6-10.5%, respectively), the greater amount of slowly moving water confirmed that overland flow was absent under conditions of forest environment. Not even the drainage treatment altered this positive ratio of the runoff constituents. During the third period, under stabilized hydrology and stand conditions, the accelerated and rapid runoff increased again, however maximally by 10% and 4%, respectively, not reaching the initial size of the calibration period.

Climate change is expected to influence the distribution and population dynamics of many insect pests, with potential severe impacts on forests. Spruce bark beetle Ips typographus (L.) (Col.: Curculionidae, Scolytinae) is the most important forest insect pest in Europe whose development is strictly regulated by air temperature. Therefore, climate change is anticipated to induce changes in the pest's distribution and development. We used the PHENIPS model to evaluate climate change impacts on the distribution and voltinism of spruce bark beetle in the Czech Republic. Two future time periods - 2025-2050 (near future) and 2075-2100 (distant future) - are addressed. The period 1961-1990 is used as the reference. We found that while a two-generation regime dominated in the Czech Republic in the reference period, significant three-generation regime regions are projected to appear in the near future. In the distant future, the three-generation regime can be expected to occur over all existing coniferous stands in the Czech Republic. The analysis of altitudinal shift of n-generation regime regions indicates noticeable expansion of Ips typographus development to higher elevations, leading for example to disappearance of one-generation regime regions in the distant future. Uncertainties and limitations of the presented findings are discussed as well.

This study is focused on substitute European larch stands in the Krušné hory Mts. (northern part of the Czech Republic). Research was conducted within larch thinning experiment Kalek (780 m a.s.l. in the category Piceeto-Fagetum oligo-mesotrophicum - Calamagrostis villosa). Results showed that the aboveground biomass of the investigated substitute unthinned larch stand represented approximately 102 thousand kg of dry matter per ha at the age of 20 years. Stemwood (ca 59%) is the most important part of the aboveground biomass. Needles, live and dead branches accounted approximately for 6%, 17% and 11%, respectively, and stem bark only for 7%. At the age of20 years, the investigated substitute unthinned larch stand accumulated: nitrogen - 307 kg, phosphorus - 21 kg, potassium - 136 kg, calcium - 122 kg, magnesium - 53 kg per hectare. Thinning with consequent removal of aboveground biomass may result in nutrient losses. Especially, the removal of whole tree biomass by thinning for chipping in areas previously degraded by acid deposition may result in calcium and magnesium deficiency because of their low content in forest soil. On the other hand, thinning supported faster growth of trees left after thinning and consequently faster biomass and nutrient accumulation. Our results supported the recommendation that the use of biomass from thinning for chipping should be limited to stemwood only and the remaining aboveground biomass (mainly needles and branches) should be left in the forest ecosystem for decomposition in conditions of the historically disturbed area of the Krušné hory Mts.

The noctuid C. trapezina (CT) has been considered an occasional predator of other Lepidoptera larvae. Functional/numerical response of predator and/or prey was estimated using 27 years of time-series data from Slovakia and stepwise multiple regression models (SMRM). SMRM were used to examine a possible delayed density-dependent feedback. We constructed 12 order-three autoregressive models [AR(3)] for CT and candidate prey. Independent variables were abundance of C. trapezina and abundance of candidate prey in lags 1, 2, and 3. Model variants were: (1) predation on free feeder models (FFM); (2) predation on shelter feeder models (SFM); (3) predation on the sum of 8 species models (S8M); (4) predation on all Lepidoptera models (ALM). Models were constructed for three areas (created by grouping sites based on significant correlations among CT populations). Additional comparative models were constructed for another three noctuid species and one geometrid species to compare their regression parameters under the same conditions as for CT. In total, 48 AR(3) SMRM were constructed for comparative species. A negative response of shelter feeders was found in models mainly for CT. We also found the positive response of CT growth rate to abundance of shelter feeders in lag 3 on two out of three models. This pattern was not found for any other comparison of species in the analysis. Possible mechanisms for these results are discussed.

We examined the impacts of variation in overstory structure and burning regime on understory vegetation in the longleaf pine (Pinus palustris Mill.) forest of the Okefenokee National Wildlife Refuge in southeastern Georgia, U.S.A. On sandy upland sites surrounding the Okefenokee Swamp and on islands, we established five randomly-located 0.04-ha plots within each of six study areas. The plots varied in overstory density, past management and fire regime. We measured overstory tree size of longleaf pines in the 0.04-ha plots and percent cover of ground cover species in five 1-m2 subplots nested within each 0.04-ha plot. We also calculated diversity indices for the ground cover species. There was no significant relationship between overstory basal area and any diversity measure. Even at the subplot level, there was no significant relationship observed between the diversity measures and distance to the nearest tree, presumably a surrogate for overstory density. The diameter (DBH) of the nearest tree exhibited a slight influence over the Shannon Index, and the nearest tree's height was significantly related to evenness in each subplot. There were varied relationships between individual species and fire regime or nearest tree measurements. There was a definite, but statistically insignificant, trend of decreasing diversity with increasing years since the last burn. Height of the nearest tree positively influen­ced evenness, probably reflecting the influence of stochasticity and amount of needle deposition (influencing fire behavior) over a wide area. Within the generally equal fire-return interval across sites, individual fire-events and site-specific behavior apparently influence understory diversity. It is not surprising that the last burn would affect species richness, even more so than the number of growing-season burns, other studies support this observation. The presence of obligate seeding and (clonal) sprouting as dominants in the ground cover suggests that the fire-return interval is not regular. The cycling of fire-return intervals, even within the manage­ment-prescribed 2- to 4-year range, and the variation by microsite appear to provide sufficient variability of disturbance to create diversity in the ground-level cohort. Site-specific relationships between particular species and the nearest tree suggest that even a narrowly-prescribed fire management regime can provide sufficient diversity.

Estimation of stand growth is crucial for forest planning. Estimations were usually done using fixed values, and recently growth equations have been used. An alternative is through stand growth models. The objective was to develop a simple model for Nothofagus pumilio stands with full density along site quality and age gradients. The sample was obtained from 125 stands. Data on forest structure and samples for tree-ring measurement were taken in all trees to estimate growths using biometric models previously developed. The growth values of each plot during the last twenty years were calculated to fit the model, using the ratio of total volume increment/basal area as an independent variable. The developed model gives a ratio between stand volume increment and basal area (m/year) in relation to the site quality and stand age. The statistics (r² = 0.819, mean error = 0.019, absolute mean error = 0.033), residual analysis and biological performance were satisfactory. The obtained stand growths varied between 1 and 20 m³/ha/year. This simple model allowed to estimate growth values at a stand level from easy field measurements from forest inventories.

The study was an attempt to determine the dynamics of heartwood formation and the radial and axial distribution of sapwood and heartwood in stems of European larch (Larix deciduas Mill.) representing the dominant stand according to Kraft. Correlations were found between the rate of heartwood formation and the social class of tree position in the stand, the age of trees, forest site type and height of trees. Moreover, radial and axial variation was observed in the distribution of analyzed wood zones depending on the height of measurement, the age of cambium and the dimensions of the analyzed tree. Results were analyzed statistically, which facilitated an assessment of the relation between the dynamics of heartwood formation and age, the social class of tree position in the community as well as dimensions, i.e. the thickness of the sapwood ring and the radius of heartwood cylinder. The greatest strength of the relation was determined between the ray of the heartwood and the stem radius (R² = 0.98), with cambium age and number of heartwood rings (R² = 0.93). A much smaller relation was determined between the width of the sapwood ring and the stem radius (R² = 0.13).

This study describes the parameterization of biomass functions applicable to oak (Quercus robur, Quercus petraea) trees grown in the conditions of Central-European forestry. It is based on destructive measurements of 51 grown trees sampled from 6 sites in different regions of the Czech Republic important for oak forest management. The samples covered trees of breast height diameter (D) ranging from 6 to 59 cm, tree height (H) from 6 to 32 m and age between 12 and 152 years. The parameterization was performed for total aboveground biomass and its individual components. The two basic levels of biomass functions utilized D either as a single independent variable or in combination with H. The functions of the third level represented the best function for each biomass component with the optimal combination of available independent variables, which included D, H, crown length (CL), crown width (CW), crown ratio (CR = CL/H), tree age and site altitude. D was found to be a particularly strong predictor for total tree aboveground biomass. H was found to always improve the fit, particularly for the individual components of aboveground biomass. The contribution of CW was minor, but significant for all biomass components, whereas CL and CR were found useful for the components of stem and living branches, respectively. Finally, the remaining variables tree age and altitude were each justified only for one component function, namely living branch biomass and stem bark, respectively. The study also compares the fitted functions with other available references applicable to oak trees.

The aim of this study was to evaluate organic carbon content (SOC) in the surface layers of forest soils in the two Natural Forest Regions situated in Southwest Bohemia, namely Západočeská pahorkatina (NFR 6) and Český les (NFR 11). The study is based upon on two consecutive soil sampling campaigns during autumn 2003 and 2004. While the sampling of 2003 was inadequate to estimate bulk density, the consecutive campaign used a defined sample volume to permit an estimation of bulk density and quantification of soil organic carbon (SOC) for soil organic layers and the upper mineral horizon. The total sampling depth was 30 cm including both organic and mineral layer. SOC of organic horizon was on average 1.99 kg C/m². It differed by stand site type ranging from 0.70 to 3.04 kg C/m². The organic layer SOC was smallest under beech (1.03 kg C/m²), whereas it was higher under pine (2.19 kg C/m²) and spruce (2.09 kg C/m²). SOC in the mineral layer was in average 7.28 kg C/m². SOC differed significantly by the major tree species and reached 10.6; 5.67 and 7.5 kg C/m² for beech, pine and spruce sites, respectively. The average SOC for the total soil layer (0-30 cm) reached 9.33 kg C/m². The methodological aspects of regional estimation of SOC and the potential of utilization of the national forest inventory program are also discussed.

The paper deals with throughfall and soil percolation in a sub-mountain beech forest situated at the Ecological Experimental Site (EES) Kremnické vrchy Mts. (the West Carpathian Mts., Slovakia). The research was conducted in 1988-2008. The throughfall was sampled at regular periods, both from the open plot (clear-cut) and from the plot with complete stocking, covered with a mature beech stand. The soil percolation was evaluated with soil lysimeters. In 1989 and 2004, the plots were treated with cutting - with the aim to reduce the current stocking. The average amount of throughfall was 772.2 mm in the open plot and 616.3 mm in the control. The amount of soil percolation decreased with increasing depth: from 398.9 mm to 103.8 mm in the control and from 488.8 mm (surface) through 169.9 mm (10 cm) to 188.8 mm (25 cm) in the open plot. The differences between the plots were statistically highly significant. No significant differences were found between the soil horizons.

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.

The aim of this study was to compare the degree of root rot damage in two large complexes of Norway spruce stands established on former agricultural land at fertile sites. The root rot infection was observed on the stump cutting area on both intended and salvage clear fellings. Stands in Kružberk area in the Nízký Jeseník Mts. established on arable land showed very poor stability and large root rot damage at the age of 40-50 years. In contrast, stands in Lužná area in the Javorníky Mts., founded on former sheep pastures, were markedly much less damaged at the age of 90-110 years and proved to be able to provide quality timber, although they were damaged by the root rot as well.

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.

The fine root biomass represents 3,372 kg/ha in the intermediate stage of the beech virgin forest with different admixture of goat willow, where the vast majority of this biomass is located in the uppermost mineral soil layer 0-10 cm. The variability of the fine root biomass calculated from 35 sample points represents approximately 90% of the mean value and reaches the highest value within the humus layer. The total fine root length investigated in 10 cm thick soil layers decreases with increasing soil depth. A significant linear relationship between the fine root length (calculated per 1 cm thick soil layer and 1 m² of stand area) and the soil depth was confirmed, although the correlation is rather weak. The number of root tips decreases with increasing soil depth faster than the root length. As the number of tips per 1 cm of root length remains in the finest diameter class without significant changes, the reason is above all a decreased proportion of the finest root class (diameter up to 0.5 mm) from the total fine root length within the particular soil layer.

Beech (Fagus orientalis Lipsky) is the most industrial commercial tree species among more than 80 broadleaved trees and shrubs in Hyrcanian forests. In this study some of the silvicultural properties of beech were studied under a shelterwood cutting system in a regeneration unit of 25 years old stand in Sangdeh forests of Iran. Tree height, diameter, canopy cover, variety of species, frequency at different stages of growth (seedling, sapling, thicket and pole) and tree density at juvenile phase were recorded in 431 circular 1,000 m² sample plots before and after shelterwood cutting. Results indicated that tree density in the diameter at breast height (dbh) class of < 20 cm increased during shelterwood cutting. Canopy cover of regeneration unit was 78.5% in 1957, while in 2000 and after the shelterwood cutting it reached 59%. Growing stages of regeneration were 14% sapling, 21% thicket, 24% small pole and 41% pole. The shelterwood method has not been very successful in our study area due to a number of technical and potential problems.

Dioszeghyana schmidtii (Diószeghy 1935), is forest species protected by European Union. Its distribution has been studied essentially by the use of light traps. However, its biology and habitat preferences are not sufficiently known and thus its habitats may be damaged by forest management. We suggest the beating method in order to collect larvae as an useful way to record and to survey D. schmidtii. Larvae of the species can be collected by beating branches of its host plants (Quercus and Acer species) in the lower canopy (below 3 m). Optimal survey time would be the second half of May and the first half of June. Differences between the larvae of D. schmidtii and 16 similar moth larvae, as well as, Tenthredinidae (Hymenoptera) species living at the same time on the same trees are described and figured in a key to identification. The method described in the paper allows one to identify larvae in the field. Results are discussed.

The paper shows difficulties in the evaluation of the forest status when considering forests with different height structure (uneven-aged forests). It is the main problem in categorizing such forests. Concerning the actual forest management conception in Slovakia, it is assumed that the area of forests with close-to-nature management system will increase. It leads to more structured forests, as for the tree species, age, height, as well as the spatial structure. The typical vertically homogeneous forests account for only 50% of all Slovak forests, according to results from the National Forest Inventory in Slovakia (NFI SR). During the processing of NFI data the stands were divided into 2 classes as follows: (i) vertically homogeneous stands, which are classified into nine growth stages; (ii) vertically heterogeneous stands, which are classified into two growth stages (lower and advanced), and stands in the process of regeneration. New approaches are not based on the visual subjective estimation of forest homogeneity, but on objective analyses of measured values from inventory plots (tree heights, diameters, and age). The paper shows a new approach to the classification of forest stands on an example of the variability of measured heights on inventory plots from NFI.

: The paper describes the basic potential methods and their costs of maintenance of forest lands in protective zones under high-voltage power lines (HVPL) 400 kV and 220 kV. In the present situation and with available information and data, it was possible to accomplish the average cost calculations for the whole area of the Czech Republic. The paper analyses the following mechanical and chemical methods of maintenance of forest lands: full-area scrub clearing with power saw (PS), selective individual scattered clearing of trees with PS, full-area scrub clearing by milling, full-area scrub clearing by the application of herbicides and arboricides, selective individual scrub clearing of individual trees by cutting followed by spray treatment with arboricides. The maintenance of forest lands in zones of HVPL (scrub clearing) by milling belongs to the economically most convenient mechanical methods, for example when removing 3,000 trees.ha^-1, the cost of this option is 20,000-23,000 CZK.ha^-1ha in a period of 3-year periodic frequency, while the most expensive method is selective individual scrub clearing of scattered individual plants with PS at costs of around 84,000 CZK.ha^-1.

The incidence of the summer (late-seasonal) growth of shoots was monitored following the planting of Scots pine from different provenances of the Czech Republic and different planting regimes in an experimental plot in Týniště nad Orlicí. In the third year after reforestation the local populations had the highest proportion of summer growth of the shoots (18%) compared to other populations. From the second to the fourth year after planting the percentage proportion of summer shoots was determined for the species Scots pine in conditions of the Polabí region, it was 13.5% of the individuals in each year. The analysis of stem sections demonstrated double rings as a result of the cambium activation through the growth of summer shoots.

Unit hydrograph is a basic method to show changes in runoff in the watershed. The investigation of runoff changes was carried out in the U Dvou louček watershed situated at the summit part of the Orlické hory Mts., East Bohemia. The waveform ordinates of recession limbs of unit hydrographs obtained using a common approach had to be approximated by the least-squares method. Final hydrographs reflected both drainage treatment and forest stand growth influencing the runoff from the watershed. Both factors increase culmination in synergy and reduce runoff on the recession limb of the hydrograph. We confirmed increased maximum runoff taking up 25-30% of the total runoff time when waterlogged sites were drained. The culmination increased by 0.2-0.8 mm/hour indicates the runoff increased by 2-8 m³/ha/hr.

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.

Soil properties of forest ecosystems depend on synergy of both parent material and organisms living in the soil, i.e. tree species communities including related plant and animal species. However these soils were not left intact being converted into agricultural land; addition of both nutrients and organic matter and cultivation using tillage led to increased fertility of topsoil. Even long-term afforested soils show differences which are considered as legacy of past agriculture. The change remains detectable for decades; though the altered properties are obvious especially couple of years after planting (approximately 10 years). We found increased concentrations of nutrients (P, K, Ca, and Mg) and subsequent increased base saturation (V %) in former tilled soil only. Moreover, there were no differences between topsoil and subsoil properties (69% and 72%, respectively). In addition to significantly lower saturation (both 0-10 cm and 11-30 cm layers) detected in the long-term-forest and 50-year-afforested (both covered with Norway spruce stands) soils in comparison with adjacent 10-year-old afforestations, there was found significantly lower base saturation in topsoil horizons compared to underlying ones.

The paper deals with research on the biomass production of fruiting bodies of macromycetes in a submountain beech stand in dependence on selected climatic variables. The study was carried out at the Ecological Experimental Site (EES) Kremnické vrchy (Central Slovakia) in 2003 and 2004. The biomass production of sporocarps on the EES plots in the two study years was different (5.81 kg/ha of fresh biomass of sporocarps in 2003 and 39.95 kg/ha in 2004) due to better ecological and climatic conditions and higher abundance of sporocarps in 2004. It is necessary to mention that these values reflect the overall status of mycocoenoses on the plot. Unfavourable microclimate conditions and poor species composition of beech monocultures can be considered to be the main factors adversely influencing mycocoenoses in forest stands of the kind.

Infestation density of four the most common spruce bark beetle species was estimated on 15 study sites (10 trees per site) in the Kysuce model region in 2006. Five half-metre long sections of the stem were selected and dissected at the base of the stem; midway between the base of the stem and the base of the crown; just below the base of the crown; in the middle of the crown; and in the upper part of the crown. The infestation density of bark beetles, expressed as the number of mating chambers per dm², was determined. Ordinary kriging was then used to produce smooth maps and visualize spatial distribution of study species. Maps with isolines indicating high infestation were produced for study species (I. Typographus over 0.38; (I. amitinus over 0.15; (I. duplicatus over 0.11; and P. chalcographus over 0.415 nuptial chambers per dm²). Ips typographus L. remained dominant species on majority of sites having high intensity of infestation. Lower altitudes in the south-eastern part of the region were often infested by I. duplicatus Sahlberg and also by I. typographu and Pityogenes chalcographus L. Higher elevations in the north-eastern part of territory in the vicinity of border with Poland were heavily infested by I. amitinus Eichhoff (often with I. typographus). P. chalcographus was abundant on majority of territory - mainly in southern half of area. However locally, it was found in extremely high abundance. The results suggest the need for control measures set up jointly against the most abundant bark beetle species in study region.