Vilém Podrázský

Effects of air pollution and climatic factors on Norway spruce forests in the Orlické hory Mts. (Czech Republic), 1979–2014

The area of the Orlické hory Mts. has been characterised by decline and disturbances of Norway spruce (Picea abies/L./Karst.) stands since the 1980s. Currently, only three permanent research plots have been preserved from the original sixteen established plots in this region. In the present study, the health status, as indicated by defoliation, mortality, and stem radial growth, was studied in the peaty and climax spruce ecosystems in the upper elevations of the mountains from 1979 to 2014. This health status was correlated with ambient air pollution (SO2) as well as climate factors (temperature and precipitation). The health status of individual trees on the plots was determined by evaluation of the foliage status, and tree vitality was evaluated by measuring stem radial growth increment. Stress factor analysis showed that high air pollutant concentrations predisposed Norway spruce to stress from climatic events (drought, temperature changes), leading to forest decline. The most serious damage can be attributed to the combination of chemical and climatic stress. Stands with lowered vitality were attacked by secondary biotic pests (particularly bark beetle), resulting in rapid tree mortality. The damage process is marked not only by higher mortality, but also by chlorosis and necrosis of the needles. The stabilised trend in health status of the spruce stands was registered since approximately 1990s. In terms of climatic factors, the weather in June had the most visible influence on radial increment. Low temperatures and high precipitation were the limiting factors for radial growth in studied mountain area.

Effect of Tree Layer and Microsite on the Variability of Natural Regeneration in Autochthonous Beech Forests

ABSTRACT The present study describes natural regeneration on five permanent research plots (PRP) in juvenile growth and development phases (regrowth and advanced growth) in autochthonous beech forests in Broumovské stěny National Nature Reserve located in the Protected Landscape area in the northeast part of Czech Republic. The stands of herb-rich beech forests were studied in the optimum to break-up stage. Natural regeneration was not evenly spaced but rather was clustered. Mean regeneration density ranged from 1,472 to 44,888 recruits per ha. European beech (Fagus sylvatica L.) made up 78.5–98.0% of all regeneration. Sycamore maple (Acer pseudoplatanus L.) was also relatively abundant. Regeneration dominance and abundance responded to the mature stand canopy, soil skeleton, microrelief, ground vegetation cover, and surface characteristics. The results suggest a relationship between recruit height and microrelief in 4 out of 5 PRPs. We found statistically significant differences in height of natural regeneration (F(2,18843) = 191.8, P <0.001) on mounds (74.0 cm), on slopes (119.5 cm) and on pits (121.0 cm) due to high soil skeleton content on mounds with numerous rock outputs, minimum amount of fine earth and lower water retention, both necessary for recruit growth. In addition to the character of microrelief, the growth of natural regeneration was negatively influenced by mature stand density and canopy indicators.

Effects of afforestation on soil structure formation in two climatic regions of the Czech Republic.

The aim of this study was to determine the effect of agricultural land afforestation on soil characteristics. Two sites in two regions of the Czech Republic were evaluated, at lower as well as higher submountain elevations: in the regions of the Orlicke hory Mts. and Kostelec nad Cernymi lesy, afforested, arable and pasture lands were compared for basic chemical and physical characteristics. It was determined: pH, CEC, exchangeable nutrients, SOC, bulk density, volume density, porosity (differentiated by pore size), water conductivity and soil aggregate stability. This study demonstrated the important influence of previous land use upon soil characteristics. The characteristics of the arable horizon can persist for many years; in forests, the mineral horizons (15-30 cm) can persist within 15-30 years after afforestation. Afforestation, which caused an increase in soil porosity by decreasing reduced bulk density and increasing capillary and gravitational pores (increasing the water-holding capacity and soil air capacity), is important for maintaining the soil stability. The positive effect on infiltration and retention capacity resulted not only from the presence of a forest overstorey, but also from the presence of permanent grass cover of pasture land.

Influence of the mineral rock alginite on survival rate and re-growth of selected tree species on agricultural land

The objective of this work is to evaluate the effect of alginite on the growth parameters of seedlings of Douglas-fir, Scots pine and line mixture of pedunculate oak, red oak and Norway maple (broadleaves) on former agricultural land with an unfavourable hydrophysical regime. The research plot consists of 36 sub-plots, each sub- plot has a size of 400 m 2 . The following doses of alginite were applied: control (variant A without alginite), 0.5 kg of alginite (B) and 1.5 kg of alginite (C) when planting both conifers and mixtures of broadleaves. Number of seedlings on the sub-plots was 400 individuals, only in the case of Douglas-fir the number was 200 individuals. Therefore every combination of tree species and the amount of alginite had 4 replications. The parameters of growth and development of individual trees (height, increment and mortality) show that after 2 years, both doses of alginite had statistically positive effects on height increments.

Identification of agricultural soils suitable for afforestation in the Czech Republic using a soil database

Afforestation of agricultural lands may be a positive action in many cases. Especially, it is a beneficial feature for waterlogged soils, stony soils or for soils which are less fertile for any other reason and thus unsuitable for farming. Afforestation can be a very important action even in the agricultural landscape - afforested belts of agricultural land divide large farm blocks into smaller ones, or act as windbreakers and biological corridors. The value, quality and fertility of soil can be assessed in different ways. The study aims to determine the identification soil criteria of agricul - tural land which is suitable for afforestation. This evaluation process is based on Evaluated Soil Ecological Units (ESEU), in the Czech Republic known as BPEJ, database which is available for all agricultural land in the Czech Republic. The results are represented by a complete list of ESEU codes suitable for afforestation. The list of codes is supplemented by an explanation why such an ESEU code, representing a soil group with similar properties, is suitable to afforestation.

Effect of afforestation of agricultural soils and tree species composition on soil physical characteristics changes

Abstract This paper deals with the evaluation of the effect of afforestation of previously arable land to soil characteristics changes. One of the main aims was to evaluate the effects of each forest species on the soil structure quality after afforestation. Soil samples were taken at two climatically distinct subregions within the Czech Republic. Based on the different site conditions, two study sites were chosen at each locality for a total of four research sites. Detailed soil survey and basic forest stand inventories were conducted at all four sites. The first locality was established in the Rychnov nad Kněžnou district in the Protected Landscape Area of the Orlické mountains (soil type a Haplic Cambisol). The second locality was established in the Prague-East district (soil type a Haplic Cambisol and a Haplic Stagnosol). Afforestation had a positive influence on the soil physical characteristics which are important for the maintenance of soil stability. Forest cover has a major influence on increasing the soil porosity, by decreasing the reduced bulk density and increasing capillary and gravitational pores, which is crucial. Afforestation was also found to be positively related to increases in soil organic matter content in different forms, both stable and unstable, and tendency of considerable soil organic matter accumulation not only in the layer of surface humus but also in the entire soil profiles of the research sites. The main contributor to soil improvement after afforestation is the formation of stable soil aggregates. This is typical also for spruce and pine cover.

Modelling individual tree height to crown base of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.)

Height to crown base (HCB) of a tree is an important variable often included as a predictor in various forest models that serve as the fundamental tools for decision-making in forestry. We developed spatially explicit and spatially inexplicit mixed-effects HCB models using measurements from a total 19,404 trees of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) on the permanent sample plots that are located across the Czech Republic. Variables describing site quality, stand density or competition, and species mixing effects were included into the HCB model with use of dominant height (HDOM), basal area of trees larger in diameters than a subject tree (BAL- spatially inexplicit measure) or Hegyi’s competition index (HCI—spatially explicit measure), and basal area proportion of a species of interest (BAPOR), respectively. The parameters describing sample plot-level random effects were included into the HCB model by applying the mixed-effects modelling approach. Among several functional forms evaluated, the logistic function was found most suited to our data. The HCB model for Norway spruce was tested against the data originated from different inventory designs, but model for European beech was tested using partitioned dataset (a part of the main dataset). The variance heteroscedasticity in the residuals was substantially reduced through inclusion of a power variance function into the HCB model. The results showed that spatially explicit model described significantly a larger part of the HCB variations [R2adj = 0.86 (spruce), 0.85 (beech)] than its spatially inexplicit counterpart [R2adj = 0.84 (spruce), 0.83 (beech)]. The HCB increased with increasing competitive interactions described by tree-centered competition measure: BAL or HCI, and species mixing effects described by BAPOR. A test of the mixed-effects HCB model with the random effects estimated using at least four trees per sample plot in the validation data confirmed that the model was precise enough for the prediction of HCB for a range of site quality, tree size, stand density, and stand structure. We therefore recommend measuring of HCB on four randomly selected trees of a species of interest on each sample plot for localizing the mixed-effects model and predicting HCB of the remaining trees on the plot. Growth simulations can be made from the data that lack the values for either crown ratio or HCB using the HCB models.

Picea abies provenance test in the Czech Republic after 36 years - Central European provenances.

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.

Evaluation of aggregate stability of Haplic Stagnosols using dynamic light scattering, phase analysis light scattering and color coordinates

ABSTRACT Dynamic light scattering and phase analysis light scattering have been used to study organo-clay complexes and aggregate stability of Haplic Stagnosols depending on land use. The study of agricultural soils afforested for 45 years showed that the value of the effective diameter of organo-clay complexes slightly decreased compared to that in arable soil but remains still higher than that in the forest soil. Multiple linear regression statistical models were developed to predict the effective diameter of the particles. The best model (r = 0.95), where all parameters were significant (P < 0.05), included the clay content, clay carbon concentration, total iron (Fet) and soil color coordinates (L*, a*, b*). In the upper horizons, the effective diameter depends on the organic matter content, whereas iron oxides with surfaced position play the main role in the underlying horizons. Intensive tillage moves the colloidal system to coagulation and after withdrawal of arable Haplic Stagnosol from the agricultural production, the colloidal system tends to restore its peptization stability. However, it should be noted that the afforestation period (45 years) of arable Haplic Stagnosols is not enough for a full recovery of organo-clay complexes peptization stability.

Results of the research of Douglas-fir in the Czech Republic and Slovakia: a review

Abstract The paper summarises the results concerning the effects of cultivation of Douglas-fir (Pseudotsuga menziesii /Mirb./ Franco), especially in the last decades, on the intensity of production as well as non-production forest functions in the conditions of the Czech Republic and Slovak Republics. It analyses the research outcomes from the point of volume and value production in comparison with other native tree species, from the point of species effects on the soil and on the ground vegetation diversity, and from the point of stability and cultivation in the last period. The main aim was to compare this species with Norway spruce, which can be replaced by Douglas fir in suitable conditions. Douglas fir can have a favourable impact on the amount and the value of timber production, as well as on the soil and the biodiversity of ground vegetation. The stability of forest stands can also be considerably supported in this way. Hence, Douglas-fir represents a suitablealternative to Norway spruce at lower and middle altitudes and it can contribute to greater competitiveness of the Czech as well as Slovak forestry.