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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Východiska obnovy přestárlých porostů v podmínkách Lánské obory / Possible solutions to the restoration of overmature forest stands in the Lány game enclosuregame-park

Ambrož, Robin January 2015 (has links)
Possible solutions to the restoration of overmature forest stands in the Lány game enclosure -- this is a problem that generations of foresters in the Křivoklátsko region have been faced with. The restoration has often been postponed; as a result, there has been a remarkable increase in the number of such stands in the game enclosure. Currently, almost a third of the game enclosure is covered by stands, predominantly beech, older than 160 years, and the suggestions on how to restore these stands are by no means unified, not only within the framework of the relevant authorities, but also among the management of the Lány forestry administration. In the past, the disintegration of stands in the highest age class was dealt with by a massive planting of large-sized plants in the whole area of the game enclosure, which has brought and will continue to bring about a remarkable increase in the forest protection costs. The aim of this PhD thesis is to answer the questions concerning the restoration of the local beech stands and to propose a solution that would be efficient in the long term. The basic questions have been phrased as follows: In what condition are the extensive large-sized plant plantings? What is the number of overmature forest stands in the Lány game enclosure and what will their future development be? Are these stands still capable of producing a sufficient number of beech seeds to ensure successful natural regeneration? In what way should we restore these overmature forest stands? How should we protect them from the game damage? It was necessary to find some of the answers within the framework of intermediate scientific tasks; however, the finding of a conceptual solution to the restoration of the game enclosure remained the main goal of this work. To fulfil the goals of this thesis, it was necessary to perform the inventory of large-sized plant plots; it was found out that the total number of individuals planted in the Lány game enclosure until the end of 2011 was 28,994 at 840 plots. The plantings established in 2011 were surveyed as to their vitality and height increment between the years 2011 and 2014. In 2015, a sample was selected on which the condition of the root system was analysed according to the type of a container used for the raising of large-sized plants. It is evident from the results that despite considerable investment in fencing, the large-sized plant plantings are very often damaged by game and have to be repeatedly reinforced. The root system analysis revealed that a significant number of individuals show serious root system deformations. Consequently, the optimization of large-sized plant planting was proposed. The condition of the beech stands at PRP was ascertained with the aid of the FieldMap technology; the stand development prediction was carried out by the growth simulator SIBYLA. The verification of the fertility of the overmature beech stands took place at smaller plots demarcated within PRP. The results show that the occurrence of game eliminates natural regeneration in these stands; thus, it is necessary to find a way which will not be only efficient, but also economical. The fertility verification proved that despite their advanced age, the beech stands preserve their ability to produce seed material, which could be used for regeneration under a shelterwood. Finally, a model regeneration block presenting two possible reproduction methods (with maximum utilization of natural regeneration and accelerated one) was designed on the basis of both the differentiation of the game enclosure and the localization of stands with the highest degree of regeneration urgency.
62

Struktura, vývoj a pěstování smrko-bukových porostů v západních Krkonoších / Structure, development and growing spruce-beech stands in the western Giant Mountains

Bulušek, Daniel January 2016 (has links)
The subject of dissertation is to evaluate the structure, development and silviculture spruce-beech stands in the western Giant Mountains and design of differentiated silviculture of these stand in similar environmental conditions. The aim of this study was to describe the structure of trees natural regeneration and the structure of tree layer, evaluate their current development and to predict future developments and based on detailed analysis of habitat and stand conditions to propose a framework directive management of the studied stands and stands located in similar habitat and stand conditions in the Giant Mountains. For this purpose were used primarily permanent research plots (PRP) 1, 2, 8, 9 and 35 with the dimensions of 50 × 50 m, which were established and regularly monitored since 1980 (PRP 1, 2, 8 and 9), PRP 35 were established in 2004 and a number of other sub-plots. For the evaluation of natural regeneration was on each research plot marked transects 50 × 5 m (250 m2). Measurement of the natural regeneration included all individuals present at the individual transects, whose diameter breast-height diameter was smaller than 7 cm. After measuring all the data was evaluated spatial, species, height and thickness structure. To evaluate the tree layer were measured all individuals on permanent research plot with breast-height diameter greater or equal than 7 cm. The measured data were subsequently evaluated by mathematical-statistical methods. Visualization of the tree layer and development simulation was performed using the growth simulator biodynamic of forest SIBYLA. The results show that the structure stands was on individual permanent research plots very variable. Variability occurred in natural regeneration even within individual transects. Significant differences are evident in the development of stands that provide space for a wide range of near natural differentiated care within of stands type and individual types and subtypes of forest development.
63

Stav a vývoj přirozených lesních porostů s jedlí v CHKO Bílé Karpaty

Volařík, Daniel January 2006 (has links)
No description available.
64

Pronikání buku (Fagus sylvatica L.) do smrkové monokultury z jednotlivě vtroušených mateřských stromů - iniciální fáze transformace porostu

Dobrovolný, Lumír January 2010 (has links)
No description available.
65

Rekonstrukce porostů náhradních dřevin - problematika valů

Pop, Martin January 2010 (has links)
No description available.
66

Přísevy jetelovin a trav do travních porostů

Komárek, Petr January 1998 (has links)
No description available.
67

Vliv extenzivního obhospodařování pastevních porostů ve vztahu k porostovým a hydropedologickým parametrům

Hejduk, Stanislav January 2000 (has links)
No description available.
68

Vliv vodního režimu na vybrané travní energetické druhy (suchovzdornost) ovsík vyvýšený (Arrhenatherum elatius), sveřep horský (Bromus carharticus) a bojínek luční (Phleum pratense) / Influence of water regime on growth and quality of selected grass species

BÁRTA, Ondřej January 2014 (has links)
This thesis describes the importance and use of permanent grasslands, or more so-called energy grasses used in the energy sector. For our study we examined these three grasses: Ovsík vyvýšený (Arrhenatherum elatius), Sveřep horský (Bromus carharticus) and Bojínek luční (Phleum pratense). Another, the main task was to determine their resistance to drought. The results based on laboratory work, which between them compared the two variants. One was simulated normal emergence of the species and the second emergence stressed by lack of water. Based on these results, we conclude that we can not say that it would be a downright drought-resistant types. For the two studied species of grasses (Bojínek and Ovsík) are obvious differences in resistance to drought. Sveřep horský (variety - Tacit), however, proved to be the most drought-resistant species. While most sprouted out bojínek luční (variety - Sobol).
69

Tree spatial patterns of dominant tree species in selected natural forests of the Czech Republic

Janík, David January 2013 (has links)
No description available.
70

Využitelnost travinných porostů pro výrobu bioplynu / Assessment of use of graminoid stands for biogas production

RYCHTEROVÁ, Jana January 2009 (has links)
The MSc. Thesis is part of project No. 2B06131 of the National Research Programme of the Czech Republic. The aim of the work was to assess selected herbaceous stands in repsct to their use for biogas production. A working hypothesis was set as follows: The biogas production per unit organic matter does not differ between biomass coming from different types of grasslands/biotopes. The results support the hypothesis. The sites studied were located in altitudes from 400 to 800 m a.s.l., water availavility ranged from mesexerophytic to hydrophytic conditions and nutrient availability ranged from mesooligotrophic to eutrophic conditions. According to plant species composition, the stands corresponded to stand types Alopecuretum pratense, Phalaridetum, Poetum pratense, Arrhenatheretum elatioris, Festucetum pratense and the ruderal stand type. In spite of these differences, biogass production estimated according to ZIFO was very similar for all stands, i.e. in a range of 518 {--} 546 NL biogas per kg organic substances in dry matter and had almost identical methan content. The results indicate that, in assessment of suitability of herbaceous stands for biogass production, biomass production is of greater importance than plant species composition.

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