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The present study examines the relationship between the quality of timber production and the species and structural diversity of forest stands. The data used came from a regional forest inventory of the University Forest Enterprise "Kostelec nad Černými lesy", Czech Republic. The inventory was performed from 2009 to 2011 on 1,188 sample plots that represented 86 strata defined by the combination of three variables: site (5 categories), age (12 categories) and canopy cover (5 categories). On each sample plot, we quantified 171 partial biodiversity indicators that represented species or structural diversity. The quality of timber production was specified by four indicators quantified using local assortment tables. In total, we analysed 58,824 univariate linear regressions describing the relationships between diversity indicators and timber quality in individual strata. The results revealed that their relationship changes with stand age. The proportion of the best-quality assortments increases with the increasing species richness in all age categories.

To assess the residual damage a 100% inventory method was employed in pre-hauling and post-hauling, alongside skid trails and winching strips. Inventory was executed within 6 m from each side of the skid trail or winching strip centreline (12 m width). Besides the data analysis to choose the best alternative depending on residual damage the Analysis of Multiple-criteria Approval (MA) was applied. In the winching strip, our results demonstrated that depending on the density of standing residual trees the most unfriendly alternative to standing trees was a short-length method (SLM) which damaged 27.9% of the total standing trees and the best alternative was a tree-length method (TLM) (11.89%). The most unfriendly alternative to regeneration in winching and skidding operations was SLM with damaged 21% and 9% of all seedlings, respectively. In the winching strip TLM is the best alternative depending on the number of damage trees but 72% damage degree was deep. Alongside the skid trails the highest number of damaged trees occurred in TLM (44 stems) and the lowest was in the long-length method (LLM) (10 stems); according to the density of trees also the greatest damage to trees occurred in TLM (16.73%) and the lowest was in LLM (3.13%). In addition (in winching and skidding operations), 14.31, 8.79 and 18.19% of residual trees and 9, 11 and 16% of individuals of regeneration were damaged in TLM, LLM and SLM, respectively. The results of data analysis (by SPSS and MA) indicated that the friendly alternative to residual stand in the north of Iran is a long-length method.

A pot experiment was carried out to examine the effect of inoculation with arbuscular mycorrhizal fungi (originated from a soil polluted with Pb) on root mycorrhizal colonization, survival, growth and volume production of black and white poplar plants grown on polluted (Pb) and non-polluted soils. In July, mycorrhizal inoculation had no significant effect on stem growth and volume production of black and white poplar plants grown on polluted and non-polluted soils. In October, mycorrhizal inoculation improved only parameters of white poplar plants (survival on polluted soil; growth and volume production on polluted and non-polluted soils). Mycorrhizal inoculation increased the root colonization percentage of black and white poplar plants on both soils. Generally, black poplar plants had significantly better survival, root mycorrhizal colonization, stem growth and volume production than white poplar plants. Although mycorrhizal and non-mycorrhizal plants of black poplar on polluted soil had higher survival, growth and volume production than white poplar, however in white poplar mycorrhizal inoculation improved the efficiency of plants on polluted soil.

The nun moth (Lymantria monacha /L./) is a polyphagous pest feeding on coniferous and deciduous trees in Eurasia. This paper, based on a literature review, presents an overview of the nun moth outbreaks in Czech forests from 1784 to 2010 in terms of host tree species. At least 22 genera of host trees, bushes and herbs were recorded in the Czech Republic. On the other hand 2 genera were evaluated like non-hosts and 4 genera like indifferent. The nun moth defoliated mainly coniferous forests (almost 90 % of all recorded outbreaks with known data about host trees) in the Czech Republic. Forests with mixture of coniferous and deciduous trees were defoliated nine times less frequent, and only insignificant portion were recorded in clearly deciduous forests. Although wide host range, the nun moth has defoliated predominantly spruce forests (almost 70 %). Mixed coniferous (with mixture of spruce, pine, larch, fir) forests were attacked three times less frequently then the spruce forests. Pine and larch forests were defoliated in low range. Defoliations were sorted also according the intensity. Spatial distribution of the recorded outbreaks was displayed in maps.

Road cross section, as one the main effective factors in relation to fill and cut volume, was effective in costs and disturbance of forest road constructions. In this research, the effect of a few physiographic parameters on forest road cross section was evaluated. For this purpose, 192 cross sections on forest roads were delineated selectively in mountain forests in the north of Iran. The physiographic factors including elevation, hillside slope, slope aspect, rock base, and soil texture as well as cross section width were measured. After evaluating the data in terms of normality and homogeneity, it was analysed by Spearman's and Pearson's correlation tests using SPSS20. One-way ANOVA, two-way ANOVA, and Duncan grouping tests were used to determine the effect of the above-mentioned factors both separately and simultaneously. Results showed that the parameters including hillside slope, rock base, and soil texture had a significant effect. Elevation was recognized as a regional parameter due to the lack of any relationship with cross section. There was no significant relation between slope aspect and cross section. The hillside slope was defined as the most effective parameter on the cross section.

Romania is also included among the European Union countries where deforested areas have radically increased in recent years, with mountain areas being the most affected. The pressure on the forest fund was analysed in the Maramureş County, as one of the most deforested counties of Romania. In view of assessing the forest area evolution, forested and deforested areas have been calculated for the period 2001-2012, using the Global Forest Change 2000-2012 database provided by the Department of Geographical Sciences, Maryland University. The economic pressure quantification was monitored by developing a database on economic activities based upon the loggings carried out in the period 2001-2012. This database comprises the number of companies, their turnover, profit and the number of employees for the economic sectors causing pressure on the forest fund. The outcomes show a dramatic increase in deforested areas, amounting to over 16,500 ha in the Maramureș County. Nearly 5,000 ha have been deforested in Borșa, the commune with the largest deforested areas in the period 2000-2012, causing major imbalances to the local ecosystem.

The contribution presents the results of a 5-year (2008-2012) dendroecological research in a Norway spruce (Picea abies [L.] Karst.) clone forest (Northern Slovakia). Due to different climatic and soil moisture conditions in the monitored years, different seasonal courses of stem increment formation were observed using band dendrometers with continuous data recording. The lack of precipitation affected growth processes mainly during the growth culmination and at the end of summer. The multiple regression analysis of the impact of individual factors on stem circumference changes on the basis of their partial correlation coefficients revealed that the individual environmental characteristics influenced daily stem radial changes with time lags of one to ten days. The results of the analysis of variance showed that the stem radial reactions to climatic and soil moisture factors were not significantly different between the clones.

The paper deals with the evaluation of economy of forestry companies. The evaluation stems from the results of economic analyses of enterprises that are further monitored in the context of forestry and development of economic financial ratios of evaluated companies. Furthermore, the evaluation is based on real possibilities of companies stemming from resources which they have at their disposal and on the facts that occurred in the selected companies in the monitored period. The development of important factors influencing the whole branch of forestry and their real state are introduced in the first part of the paper. After that, methods used in financial analysis of enterprises are described. The fact that forest land in the Czech Republic covered 2.66 million hectares in 2014 and its proportion in the total area of the country is 34% adds importance to the topic (Czech Statistical Yearbook 2015).

Protocols for the in vitro propagation of two endangered plant species in the Czech Republic, Gentiana verna L. and Jurinea cyanoides (L.) Rchb., were established. In G. verna, the induction of organogenesis on vegetative shoots was successful on the basal 6% agar WPM medium with 200 mg.l^-1of glutamine, 200 mg.l^-1 of casein hydrolysate, 30 g.l^-1 of sucrose, 0.2 mg.l^-1 of BAP, and 0.1 mg.l^-1 of IBA. The multiplication of primary explants was achieved on 6% agar basal MS medium with the same concentrations of substances mentioned above. In J. cyanoides, the induction of organogenesis and multiplication of its vegetative shoots were successful on MS medium with the same concentration of added substances used in G. verna. On the basal MS medium of 1/3 concentration with 3 mg.l^-1 of IBA 70-75% rooting efficiency of G. verna microcuttings and 40% rooting efficiency of J. cyanoides microcuttings were reached. The mortality during acclimatization did not exceed 20% for G. verna and 25% for J. cyanoides.

Norway spruce (Picea abies [L.] Karst.) provenances from Central Europe (Hercynian-Sudetes area) were evaluated in a long-term experimental project (Germany-Czech Republic) 36 years after the outplanting. The growth characteristics, mortality and qualitative morphological characteristics of 64 spruce provenances were evaluated on the experimental plot Ledeč-Zaháj, in the Czech-Moravian Highland region of the Czech Republic, in typical conditions for Norway spruce cultivation. Results show 15-20% differences in height and radial growth between provenances and insignificant differences in qualitative characteristics e.g. stem shape, branch density and shape and also health state. Environmental variables that significantly influenced production characteristics include longitude, latitude and altitude of the original locations of the provenances, while average annual temperature and average annual precipitation were not significant. Given conditions of the experimental plot, optimal production occurred with those provenances originally from 49-51 N latitude and 13-20 E longitude.

Quantitative and qualitative characteristics of Persian oak (Quercus persica) were studied in relation to altitude and slope variations in Ilam province. A total area of 1,500 m2 (30 × 50 m) was covered in five altitudinal classes ranging from 800 to 1,800 m a.s.l. Samples were taken based on a systematic random sampling method with 24 sample plots at each class. In total, 120 sample plots (in five classes) were collected covering four gradient categories ranging from < 20 to > 60%. An analysis of variance (ANOVA) was carried out to compare differences between group means in gradient categories and Duncan's post-hoc test was performed to reveal differences between the means of various quantitative characteristics (e.g. growing stock, basal area, diameter at breast height, tree height and regeneration) and the altitudinal classes. The Kruskal-Wallis test was used to examine the differences between the means of qualitative variables and different altitudes and slopes categories. The results indicated that variations with altitudes may have a higher impact than slopes on the quantitative characteristics of the oak stands in the region while the qualitative variables of the native species were influenced by both altitudes and slope variations.

Clonal propagation is widely used for Acacia breeding and commercial planting. When a large number of clones are handled, problems with mixings are commonly confronted. Detection of admixture in Acacia clones based on morphology particularly at seedling stage is not feasible. However, molecular markers are commonly used to test the genetic fidelity of planting materials. This paper reports the detection of mislabelling in Acacia clonal progenies using a sequence tagged microsatellite (STMS) genetic marker system. Progenies from two mapping populations were clonally propagated and field planted for phenotypic and genotypic evaluation at three locations in Malaysia: (a) Forest Research Institute Malaysia field station at Segamat, Johor, (b) Borneo Tree Seeds and Seedlings Supplies Sdn, Bhd. (BTS) field trial site at Bintulu, Sarawak and (c) Asiaprima RCF field trial site at Lancang, Pahang. During field planting mislabelling was reported at Segamat, Johor and similar was suspected for Bintulu, Sarawak. Screening revealed mislabelling events in both populations. A total of 18.52% mislabelling incidences were detected from both sites, of which 17.39% of mislabelling was detected for fibre length cross and 20% for wood density cross. The assignment test efficiently reestablished the mislabelled ramets to the respective clones. Future studies should be focused on the utilization of a higher number of markers, e.g. SSR or SNPs to increase a discrimination power. A high number of SNPs can be generated within a short period of time compared to SSR, but SNPs could be cost inhibitory. Multiplexing microsatellite combinations along with sample bulking will further reduce the processing time when screening large populations. The use of assignment test would efficiently assign mislabelled individuals to the respective clones. It is concluded that checking for mislabelling is imperative for future breeding and for analyses such as QTL mapping where a correlation between genotypic and phenotypic data is determined.

Service tree (Sorbus domestica L.) is a significant species with regard to the biodiversity of specific habitats. Its reproduction in natural conditions appears to be problematic and in the interest of preserving the countryside, forests and their biodiversity, it is necessary to apply controlled reproduction procedures. Therefore, when applying such procedures it is of crucial importance to optimize the storage and use of seed material. The objective of the present article is to evaluate the germination rates of seeds which were stored in the long term. 95% of the seeds preserved at low temperatures above zero in a normal refrigerator for 8 years germinated after stratification in wet sand. The germination rate of the same seeds when moistened without stratification was 0%. However, after removal of the seed coat, 76% of these seeds germinated without stratification. Storage of air-dried seeds in the cold (at temperatures above zero) is ideal and is better than freezing them to -20°C, as reported in the literature. Wet peat is completely unsuitable for stratification.

Production of raw wood material and its regulation has a great ecological and economic importance in every country. The aim of the paper is to analyze the prospective production of raw wood with respect to the expected basic tree species composition and assortment structure on an example of long-term development of selected indicators of forest condition in Slovakia. For this analysis we used data on the area, growing stock and planned decennial timber felling in the forests of Slovakia in 1980, 1996 and 2003. The production potential of forests was evaluated on the basis of the annual perspective allowable cut by 2020, from which the prospective production of assortments was derived using the models of assortment yield tables of tree species. The results show that in the forests of Slovakia there is an about half proportion of coniferous and half proportion of broadleaved tree species, very good structure of growing stock as well as its trend in the last years. Production of raw wood assortments for industrial processing for the years 2010-2020 is limited by the volume 6.3-6.4 mil. m³. About one half of this volume comes from coniferous and the other half from broadleaved tree species. For coniferous tree species the proportion of spruce and fir is 87% and for broadleaved tree species the proportion of beech and oak is 80%. For coniferous tree species sawmill assortments have a decisive, almost 70% proportion. Regarding broadleaved tree species, pulpwood assortments with 47% proportion prevail, although with 11% the highest quality assortments for the production of veneer from beech and oak are also significant.

This study evaluates the effect of the identified pathogenic races E1, E2 and E3 of the leaf rust Melampsora larici-populina on some growth traits and biomass yield in the species Populus nigra. A field trial was conducted with 8 clones of P. nigra using fungicide-sprayed and unsprayed treatments in 3 replications of 4 plants. In the course of three years the occurrence of the rust was evaluated on a six-point scale. The plant height and stem diameter were measured during the trial. In the last year the plants were harvested and the dry weight was determined. In the untreated plants a significant negative correlation was found between the intensity of rust occurrence and the values of stem diameter and dry matter yield (P < 0.05). A decline in dry matter yield caused by the rust was low (below 9%) or zero in a half of the clones while it ranged between 19% and 28% in the other half of clones. In some clones the yield decline was relatively low although the expression of rust symptoms was rather high which could be attributed to a tolerance to the given pathogen.

European ash (Fraxinus excelsior) and sycamore maple (Acer pseudoplatanus) are considered amongst tree species as some of the most attractive forage for red deer (Cervus elaphus). The aim of this paper is to estimate branch and foliage mass browsing by red deer in young Sycamore maple and European ash in Central Slovakia and to analyze interspecific differences in browsing frequency and quantity. Altogether 665 ash trees and 701 maple trees were measured for height and stem diameter at the ground level. Red deer browsing, defined as leader shoot or lateral branch cropping, was recorded for all trees. A combination of the diameter of browsed branches and branch regression models allowed for the estimation of browsed (potentially consumed) mass by red deer. Results show that browsing occurred more frequently on maple (5 cases per tree) compared to ash (3 cases per tree); however, more total branch biomass was consumed in ash (10.7 g per tree) compared to maple (2.6 g per tree). This is because browsed branches were larger in ash than in maple. We assume that the difference in the size of browsed branches between ash and maple is relative to species-specific branch morphological and structural features.

Seedlots of sycamore maple (Acer pseudoplatanus L.) originating from three different provenance regions were collected in autumn 2012. The seed quality, namely vitality and germination rate, was assessed according to Czech conventions. There were four replications within each seedlot, i.e. twelve treatments altogether for each experimental variant. The effect of gibberellic acid on germination and vitality was studied using three treatments including a control for germination capacity and three treatments including a control for emergence rate. The data shows that the gibberellic acid did not substitute for the stratification procedure as it did not improve the germination capacity of seeds with pericarp when compared with stratified seeds; however for seeds without pericarp the gibberellic acid improved the germination capacity to the level of stratified seeds. The data also shows the positive influence of gibberellic acid on emergence rate. All variants where acid gibberellic was applied have a statistically higher emergence rate than the control. The increase was about 50% higher than in the control, i.e. without the influence of gibberellic acid.

Compost leachate is produced by conversion of municipal waste to compost. It contains significant amounts of organic materials, nutrients, soluble salts and small amounts of some heavy metals. Adding compost leachate to the soil can pollute it, and also improve soil fertility. In this study, we investigated absorption and growth performance of Populus deltoides under irrigation with leachate of the Compost Plant of Rasht. At the beginning of the growing season, in mid-March 2013, cuttings were processed from young, one-year-old seedlings of Populus trees in the greenhouse of the Safrabaste Poplar Research Station. Cuttings were planted in pots filled with loamy-sandy soil in the vicinity of the area with 40cm depth. Compost leachate was taken from a collection reservoir where leachate from the open composting of organic municipal wastes and various gardening and plant wastes had been collected. Five treatments were applied to plants: (C) tap water (control), (P) pure leachate, (3:1) three units (by volume) of leachate mixed with one unit of tap water, (1:1) and (1:3). The growth of tree diameter and height was measured bi-monthly. Aboveground (stem, branches and leaves) and root biomass was inventoried at the end of the growing season. Concentration of elements was determined every three months. Overall, growth parameters in 1:1 and 1:3 treatments were similar together and there were no significant differences between them (P < 0.05). Pure treatment had minimum growth because of a high concentration of solvable salts in leachate such as sulphur that causes salinity and high EC in soil. Treatment1:3 exhibited the greatest overall aboveground and root dry mass. Total aboveground dry mass of leachate treatments and water was 202.25 and 47.58 g, respectively.

The concept of sustainable development is currently known and used in many contexts across a wide range of industries. Nevertheless, specific approaches to achieving the strategy of sustainability can be found in the individual sectors. The beginnings of sustainable management in forestry go back to the mid-18^th century. Currently, certification systems contribute to sustainable behaviour in forests. In the Czech Republic, this concerns in particular PEFC and FSC certification systems. Both these certification systems include two different processes, forest management certification and chain of custody certification, i.e. including the wood-processing companies, where only certified wood must strictly be used. This article aims to evaluate the importance of certification for sustainable development in forestry. Given the clear superiority of the PEFC system in the Czech Republic, this paper focuses on the potential benefits for PEFC certificate holders. To determine the benefits of PEFC certification for sustainable development, a questionnaire survey was chosen. Assessment of the benefits for sustainable development depends on the subjective assessment of certification holders. The results suggest that the beneficial effect on sustainable development in forest management is clear in the forest property area of over 500 ha.

The aim of the submitted work was to analyze the outlook of logging perspectives in the next two decades (2013-2032) for all forests in the territory of the Czech Republic. The analyses made use of the national database of forest management plans and guidelines. For the purpose of these analyses, the forests were divided into commercially exploitable forests and forests commercially exploitable with restrictions. The latter ones included protection forests and the category of special purpose forests, i.e. 31c - forests in the territory of national parks and national nature reserves, and 32a - forests occurring in the first zones of protected landscape areas, and forests occurring in nature preserves and nature monuments. In addition to the potential total volume of timber logging, perspectives were studied separately for coniferous and broadleaved tree species as well as for individual main tree species. The derived model mean annual cut of 15.51 mil. m³ corresponds to the current timber production in the Czech Republic. Results of the analyses indicate that reduced logging of coniferous, namely spruce, timber is to be expected in the next twenty years.

A survey was conducted in the Training Forest Enterprise called Masaryk Forest in Křtiny (TFE Křtiny) in order to determine the extent of recreational use of the area, visitors' travel costs and their willingness to pay for services provided by the forest ecosystem of TFE Křtiny in the years 2013-2014. The aim of this paper is to evaluate the partial results of the research from 2013 and 2014 which was focused on the economic assessment of the recreational potential of the TFE MF Křtiny. The busiest roads in the forest road network and bike trails located in the Bílovice nad Svitavou forest district were selected. The results can be used to assess the impact of the forest enterprise on the economic and social development of the area, to measure the attractiveness, quality and facilities offered in the forest.

Interest in conifer-broadleaf mixedwood forests has greatly increased due to continuous demand for hardwood products and a shift towards more biological or ecosystem-based management. In British Columbia, more than 30% of the productive forest land is a conifer-broadleaf mixture and current forest regulations are more conifer biased rather than maintaining a mixed-species condition. The aim of this study was to examine the impact of paper birch on white spruce growth. Spruce growth data from 10 to 18 years old complex stands indicate that radial, height, and stem volume was not impacted by retaining up to 3,000 stems.ha^-1 of birch. Similarly, growth and yield model projections suggest spruce-birch stands would be more productive up to a threshold birch density (3,000 stems.ha^-1) than pure spruce stands. At a 4% real interest rate, the removal of birch from these stands does not appear to be warranted as an investment. The results suggest that instead of encouraging uniform broadleaf removal across conifer plantations, mixed species management strategies could enhance the forest productivity, stand diversity and resilience.

The knowledge of forest development after disturbances, particularly anthropogenic disturbances, is of major importance for forest management. Many areas of mountain forests in Europe have been affected by human activities such as felling and livestock grazing in the past and then left for natural succession. Those forests provide several ecosystem services (e.g. soil or avalanche protection) and therefore it is vital to know their developmental processes. The Norway spruce forest stand in the area of Medvědí Mt. (Šumava National Park, Czech Republic), known as the Jewish Forest, is considered an example of succession after anthropogenic disturbances. This study aimed to: (1) analyse the history of disturbances which affected the locality, (2) describe the subsequent process of forest succession which led to the development of the present forest formation. We conducted a dendrochronological analysis and a spatial analysis. The main cohort was established after a period of disturbances in the first half of the 20^th century. Both natural (windstorm) and anthropogenic (logging and livestock grazing) disturbances coincided during this period. Regeneration of low density was restricted to a short period after the disturbance and was likely dependent on the occurrence of proper microsites. Later, regeneration was probably obstructed by lack of convenient microsites and high competition of the herb layer. Nowadays, new regeneration emerges together with proper microsite at decaying wood and near mature trees. We conclude that anthropogenic disturbances can limit the density and heterogeneity of regeneration, which leads to the establishment of sparse stand. This structure can persist for decades before proper microsites accumulate and enable regeneration.

Destroying of forest lands and landuse changes have caused undesirable effects in the watershed hydrologic conditions. Landuse and vegetation are important factors in soil erosion and runoff generation. This research has been done using a runoff-rainfall model, sediment-erosion model, Geographical Information System and remote sensing to determine the hydrologic effects of deforestation on Kasilian watershed (north of Iran). A runoff-rainfall model has been presented using GIS (HEC-GeoHMS extension) and hydrologic model (HEC-HMS). The SCS method has been used for presenting the hydrologic model. It is to note that the optimized model is evaluated by other six events of floods. Then, the optimized model has been validated. Erosion potential method model has been applied in GIS environment to simulate soil erosion and sediment rate. According to the obtained results, the runoff and sediment generation potential have been increased in the Kasilian watershed due to deforestation during the last forty years.

Vegetation significantly affects hillslope mechanical properties related to shallow landslides and slope stability. The objective of this study was to investigate and quantify the effect of Oriental beech root reinforcement on slope stability. A part of Hyrcanian forest in northern Iran was selected for the study area. To do the research, the Wu model (WM) was used and data related to the distribution and tensile strength of Oriental beech roots were collected. Root distribution was assessed using the concept of the root area ratio and trenching method. Laboratory tensile tests were conducted on fresh roots for strength characteristics. The factor of safety was calculated for two different soil thicknesses (1 and 2 m) and slope gradients between 10 and 45°. The results showed that the root distribution generally decreased with increasing soil depth and the mean root strength value was 38.23 ± 1.19 MPa for 0.35-5.60 mm diameter range. The results verified a power relationship between tensile strength and root diameter. The reinforcement effect (C_r) decreased with depth and the strongest reinforcement effect was in the second soil layer (10-20 cm) which showed a shear strength increase of 1.47 kPa. The increased factor of safety due to the presence of roots in one- and two-metre soil thicknesses was 27-44% and 15-26%, respectively. The improvement effect of roots was increased with increasing slope gradient and shallower soil thicknesses.

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.

One of the critical points of Douglas fir seedling production is to optimize the time of sowing and length of pre-sowing treatment. Germination and emergence of Douglas fir seed lot of the Czech origin (CZ-2-2A-DG-1740-6-3-P) were observed in simulated warm and cold conditions in two phytotrons for 3 months. Before this procedure the seeds were exposed to different prechilling duration. The temperature in control conditions of phytotrons was stable for 28 days and then it was increased: 11, 13, 17°C in cold phytotron and 13, 17, 20°C in the warm phytotron. Seeds without stratification and stratified for 3, 5, 7, 9 and 16 weeks were tested. The laboratory germination capacity of non-stratified seeds was only 58% and it was significantly (P < 0.05, Tukey's test) lower than in stratification treatments when it varied from 92% to 96%. Non-stratified seeds did not germinate in cold phytotron and they germinated very slowly (germination rate at the end of experiment was 7%) in warm phytotron. The germination capacity of seeds both in the phytotron and in the laboratory was observed in treatments with prechilling of seeds longer than 7 weeks in warm conditions and only for seeds after 16 weeks of prechilling in cold conditions. The highest emergence rate of seeds (84%) was found in the warm phytotron after 16 weeks of stratification. Comparable results were reached only for 9 weeks of stratification in the same phytotron. The results suggest that the prolongation of the standard 3-week prechilling period helps to increase germination capacity and emergence rate of seeds. Future research should focus on optimal length with regard to more seed lots and also on seedling quality parameters.

The prosperity of various forest regeneration methods was evaluated on the prepared windthrow area established in 2010 in a previously allochthonous coniferous stand growing in mid-elevations of the Czech Republic. The forest regeneration variants were as follows: (1) "planting" of target species (Picea abies [L.] Karst.) and Fagus sylvatica (L.), (2) "seeding" of pioneer (non target) species (Betula pendula Roth) and (3) spontaneous "succession". Two years after windthrow the "planting" was evaluated in accordance with the Czech forestry law as regeneration method with sufficient attributes, density (6,000-9,000 indd.ha^-1) and regular spatial distribution of target tree species. The "seeding" and "succession" variants showed a insufficient attributes of target tree species - total density ca 3,000 indd.ha^-1 (being ca 1,000 indd.ha^-1 higher than 20 cm) and irregular distribution across the plot. The non-target species birch on the "seeding" variant showed a high density of plants (131,000 indd.ha^-1) being eight times higher than the succession variant. The cost of the regeneration treatment was different between the variants - planting: 5,000-6,000 EUR.ha^-1, 1,300 EUR.ha^-1, succession: 1,000 EUR.ha^-1. Comparing to "planting" the higher diversity of tree species and higher density of non-target species (20,000-134,000 EUR.ha^-1) in the "seeding" and "succession" variants promise success for the future, however the real potential of regeneration methods that were used will be clear after long-term observations.

Different variants of regeneration felling or different light conditions (total site factor 15-95%) and weed control were evaluated in relation to the 4-year development of individuals of regenerated sessile oak. The regeneration density is not dependent on light conditions. The highest mortality occurs on the open area of clear felling. For a certain time in youth, it is possible to consider oak as a shade-tolerating species. With the increasing light intensity the diameter and height growth of oak seedlings increases proportionally, being the highest at 100% light intensity. However, to support at least medium-fast growth, the species requires minimally 50% light intensity (smaller closed clear-felled areas). On the other hand, more extensive unprotected cleared areas appear to be quite unsuitable at the initial stages of regeneration. The positive effect of weed control on the success and growth of natural regeneration is questionable. We recommend developing the regenerated stand by means of a series of small-area (about ≤ 0.3 ha) two-stage felling with a medium-long regeneration period (15-20 years).