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The aim of the article is to evaluate the development of plantations of differently performing parts of the mountain spruce population in the area with high nitrogen deposition. The high nitrogen compounds load threats the stability of the forest stands and consequently affects the forest functions on mountainous sites over long time. An important measure to reduce the sensitivity of forest ecosystems is also the support of a high level of biodiversity. This means a maintenance of intraspecies variability within populations. The first results of the experiment were in accordance with previous experience with other mountain spruce populations as the initially slower-growing seedlings showed the best growth and health after being planted in mountain conditions. On the basis of these results it is still possible to hypothesize that one of the options to reduce the negative impact of nitrogen in mountain climates lies in that artificial restoration strategy that does not eliminate the category of initially slowly-growing spruces.
The literature review summarises the available knowledge on black locust (Robinia pseudoacacia L.) with the focus on Central Europe. General characteristics of the species are described. The origin and introduction pathways of black locust to Europe and across the continent are discussed. The area currently covered by the species in selected European countries is summarised. The paper also evaluates the growth habits of the species and its regeneration and dispersal strategy. Attention is paid to the invasiveness of black locust. The authors discuss detrimental effects of black locust on some plant communities and habitats and mention biotopes most vulnerable to black locust expansion. The review refers to silvicultural techniques that could unintentionally promote the undesirable spread of the species. On the other hand, the paper summarises the challenging positive features of black locust, appreciates its qualities and presents examples of successful utilization.
The paper evaluates a development of mixed young stand from natural regeneration on a large clear-cut in East Bohemia, the Czech Republic. Clear-cut resulted from windblown forest stand in 2007; after wood clearing a part of plot was left for natural regeneration. The paper evaluates development of regeneration in 2011–2016. Mean number of juvenile individuals culminated in 2014 (2.6 trees/m2), density decrease in next years was affected by mutual competition. Birch (Betula pendula) and aspen (Populus tremula) as nurse tree dominated in upper height stratum. Target tree species occurred mainly in understorey (height below 1.3 m), their quantity gradually increased. Density of target trees species decreased with distance from adjacent mature forest stand. Growth of trees in upper storey corresponded to growth tables, left-hand diameter distribution affected mean stem dimensions. Above growth biomass of nurse stand was 27.9 t.ha-1 (DM) in 2016. Upper soil moisture under nurse stand was lower during the whole year (4–7%) compared to the weeded area; during summer periods short term differences exceeded 10% shortly.
The paper deals with the growth and phenotypic characteristics of Norway spruce in three separate core zones of the Gene Conservation Unit (GCU) No. G102-1 Trčkov-Šerlišský kotel-Vrchmezí in the Orlické hory/Eagle Mts. at the Czech-Polish border. The research was carried out in representative stands of all three parts of the GCU, which were selected in the direction from their core towards the periphery and outside the border. In total, 15 stands were evaluated. In each stand, dendrometric measurements and phenotypic surveys were performed on representative sets of sample trees. Tree growth characteristics reached their maximum in the core zones of all three parts of GCU, but also in the exceptionally high-quality stand T2.1, whose above-average parameters influenced the results of analyzes. Another stands, V2 and T2, situated relatively close to the core zones, were found of rather average quality according to cluster analysis, however. In the statistical analysis, the stands V3.1, V3, V3.2 and T2.1 proved to be most outlying, because of their lower (V3.1, V3) or exceptionally high (T2.1, V3.2) production and quality. In summary, according to the best growth parameters of trees, three parts of GCU can be sorted in descending order as follows: Trčkov, Vrchmezí, Šerlišský kotel. It can be concluded that the most valuable groups of trees are located in the central parts of GCU, and thus represent an important genetic resource to be protected from negative effects of a gene flow from surrounding lower quality inferior stands. Results of this study could be used for an objectification of the method of incorporation the stands into GCU complexes. In particularly questionable cases, it is recommended to use also molecular-genetic methods for this purpose.
The CTL logging method, linked to the harvester technology, has an increasing share on the total annual felling in the Czech Republic. The aim of our study was to determine the relative share of unrecorded volume in length allowances on the total volume of merchantable timber, as produced by harvesters. We also analyzed the volume differences in length allowances in assortment groups. Data were gathered from *.STM files, 221 235 spruce logs were evaluated. The total volume of unrecorded timber in length allowances of merchantable assortments represented 2.19% of the total recorded timber volume. After dividing the logs into individual assortment groups, we found that in the groups Roundwood and Aggregate, the average relative volume in length allowances ranged from 2.41% to 2.43%, while in the group Pulpwood was only 1.22%. Significant differences between the relative timber volumes in length allowances were also found in individual groups of assortments after categorization of logs according to their nominal length and midspan diameter. In the groups Roundwood and Pulpwood, we found significantly lower relative timber volumes in length allowances for butt logs compared to other logs. The results can be used for estimation of unrecorded timber volume in length allowances to supplement forest management records
The Simple Sequence Repeats (SSR) method of DNA analyses was used to clonal identification of trees in a model lime (Tillia cordata Mill.) seed orchard. Total genomic DNA was extracted by DNA Plant Mini Kit (QIAGEN) from young leaves taken from 377 sampled trees of the seed orchard. Samples were screened using selected eight polymorphic nuclear microsatellite markers. Measuring of the size of amplification products was carried out using the genetic analyser Applied Biosystems 3500. The obtained data were analysed by statistical programs CERVUS, GenAlEx 6.503. There were detected 79 different alleles at 8 loci in the 377 lime individuals from seed orchard. By applying of the 8 suitable markers to the 38 clones from model seed orchard we obtained multilocus genotypes (MLG). The obtained results illustrate the utility of the microsatellite loci for assessing spatial patterns of genetic diversity and for individual genotypes identification. 93.6 % of the sampled trees could be assigned to the clones represented in the seed orchard. The identified genetic loci were verified as highly polymorphic and could be further used for clonal identification of lime trees.
The calorific value (J g-1) of the dry matter of the Norway spruce Picea abies (L.) H. Karst. trees was evaluated. Experimental material was taken from five trees situated in Slovakia. Wood and bark samples were obtained from the discs, which were cut off from three locations, namely from the trunk, branches of tree crowns and needles. Calorific value (J g-1) of the dry matter of each sample was then determined. The impact of statistically significant factors on the calorific value capacity was determined by means of analysis of variance. The average values of the individual fractions are approximately in the range of 20,200–21,500 J g-1. Dry matter of wood and bark has the lowest calorific value, and then follows the dry matter of branches and twigs with needles. Calorific value variability is relatively low with its coefficient of variations of 0.7–2.9%. Calorific value of spruce is only 2–5% lower than calorific value of pine. Compared to deciduous trees, it is higher due to the presence of resin.
In this work, the Data Envelopment Analysis as non-parametric approach for measuring efficiency of many homogenous entities was used for the valuation of scale efficiency of the forest contractors. Forest services are provided by small and medium-sized enterprises employing up to 50 employees and individuals – self-employed persons. Results of the efficiency analysis by Data Envelopment Analysis show the average efficiency in range of 63–80%, depending on the model. Assessment of dependence on efficiency and others in the model of non-included variables (such as the business region, length of business) confirmed the presumption of their significant impact on the resulting efficiency within the chosen sample. Differences in the average efficiency of forest contractors among the regions are quite significant. Average efficiency of forest contractors was highest in the Nitra region and lowest in the Košice region. The efficiency with the length of business is slightly increasing and this dependence is also statistically significant.