National Repository of Grey Literature 102 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
The influence of climate on the radial growth of Scots pine in the northern Scandinavia
Tomeš, Miroslav ; Treml, Václav (advisor) ; Šefrna, Luděk (referee)
The presented master's thesis deals with the influence of climate on the radial growth of Scots pine in the northern Scandinavia. Trees growing at the polar treeline are sensitive to environmental changes, and therefore their wood is used to study growth responses to ongoing climate change. During the period of the 20th and the beginning of the 21st century, air temperatures and precipitation sums were correlated with tree rings and dendroanatomical data of Scots pine from northern Finland. It was found that the widths of the tree rings had a slightly increasing trend during the observed period. Within the framework of the correlation relations, the controlling influence of the air temperatures of the current July on annual increments was confirmed. Thanks to the higher temperatures of the summer season, wider tree rings were formed. In addition, May and summer precipitation have been shown to be important for the final width of the tree ring. The currently often discussed problem of decoupling the tree ring chronology curve from rising summer temperatures ("divergence problem") was not clearly observed in this work. In order to evaluate the dendroanatomical parameters, the tree rings of the studied individual were divided into four sectors with a similar number of cells in the radial file. During...
Natural restoration of mining sites: Vegetation succession and soil development: A case study from granodiorite quarries and dumps near the town Skuteč
Chuman, Tomáš ; Šefrna, Luděk (advisor) ; Novák, Jan (referee) ; Hradecký, Jan (referee)
Ir !ntroduction Environmenta| impaď caused by mining is considerab|e' The impact of mining on re|ief and landscape character is particularly substantial as could be documented on earth material transfer. While transfer of earth material caused by natural processes (erosion, sedimentation) is about 4 millions of cubic meters per year, anthropogenic transfer is close to 330 millions (Kukal' 2006) and material transfer due to mining represents the greatest proportion' lt is estimated that the surface minera| extraďion already covers 1% of the |and surface (Wa|ker & del Moral 2003). |n the czech Republic the extent of mining sites reached 0,8% in 2006 (Statistical Environmental Yearbook of the Czech Republic 2008). Miningcausesineversib|emodificationofre|ieíremovesvegetationandsoi|cover causing loss of biotopes. on the other hand mining creates new sites in the landscape e'g' water bodies, rock walls and screes. These sites are often unique and contrasting with the surrounding landscape and might harbor specific species afrer mine/quarry abandonment. Traditional approach to restoration was considered to be the restoration (reclamation) of production, whether agricultural or forestry, causing elimination of potential site diversity by morphology adjustment' topsoil application and tree planting or trefoil-grass...
Concept of critical loads of sulphur and nitrogen for ecosystems and modelling of soil chemistry and vegetation species composition of ecosystems affected by acidification and nutrient degradation for selected sites in the Czech Republic
Lebedová, Michaela ; Chuman, Tomáš (advisor) ; Šefrna, Luděk (referee)
The knowledge of the emission history and deposition trends of the main pollutants is key to understanding changes occurring in ecosystems. High levels of sulphur (S) and nitrogen (N) deposition, which peaked in the Czech Republic in the 1970s and 1980s, have caused significant acidification and damage to forest ecosystems. Due to the political and economic changes in the 1990s, there was a significant reduction in emissions and an improvement in the conditions of forest soil. Futures ecosystems development and recovery are affected primarily by climate change and still excessive nitrogen loads. To model the future development of ecosystems affected by acidification and nutrient degradation in the Czech Republic the dynamic model VSD+ Studio in combination with the vegetation model PROPS was used in this work. Two forest catchments of the GEOMON network (Liz and Uhlířská) were selected as model sites. The catchment areas significantly differed in the historical sulphur and nitrogen deposition loads. The results indicate that excessive depositions of S and N between 1970 - 1990 caused significant soil acidification and reduced the level of base saturation in both monitored locations. There is also a decrease in the C:N ratio and organic carbon content in the mineral soil. The vegetation model PROPS...
Soil and hydrological degradation of wetlands
Panocha, Tomáš ; Vlček, Lukáš (advisor) ; Šefrna, Luděk (referee)
The thesis researches the knowledge about soil degradation and the most important soil degradation processes, including desertification, erosion, the impact of agriculture on soils and soil sealing. It also deals with wetlands as ecosystems at the transition between aquatic and terrestrial systems, their definition and delineation, as well as their decline and recovery, which is very important in climate change projections. The chapter on wetlands also includes a section on international conventions and organisations. The work then focuses on wetland types in the Czech Republic and the soil types most commonly found on them, together with their soil-forming processes and water regimes. Last but not least, the thesis tries to find a link between the degradation of wetland ecosystems in relation to changes in the hydrological regime of the surrounding area and the surrounding soils. Keywords: soil degradation, wetland, wetland definition, wetland restoration, wetlands of the Czech Republic
Scots pine climate-growth response in the topographically complex landscape of the Kokořínsko region
Fišer, Petr ; Treml, Václav (advisor) ; Šefrna, Luděk (referee)
The extensive Scots pine Pinus sylvestris forests in topographically complex landscape of the Kokořínsko region in the Czech Republic are a suitable area for investigating how trees react differently to climate factors depending on local site conditions. Individual habitats are characterized by specific conditions which can influence a wide range of growth factors. It is therefore important to understand these differences also from the point of view of ongoing climate change, which threats forest ecosystems in central Europe. The relatively dry environment of the highly permeable sandstone landscape is vulnerable to increasing drought, which will increase the stress of local Scots pine population. Samples from 20 sites divided into 4 categories of northern slopes, southern slopes, plateaus and valley bottoms are supposed to sufficiently represent variability of the local terrain. Correlation of tree-ring chronologies with climate variables as well as PCA analysis revealed that the greatest differences are between plateaus and valley bottoms. In case of highly exposed plateaus, drought seems to be the most important limiting factor, whereas at the valley bottoms temperatures at the turn of winter and spring are the main controlling factor. Signifficant differences between northern and southern...
Water retention in experimental waterbasins with focus on histosols
Vlček, Lukáš ; Šefrna, Luděk (advisor) ; Kliment, Zdeněk (referee)
This thesis is being written within the framework of the project GA UK 2371/2007 "Water retention in spring areas as a tool of integrated anti-floods protection and solution of problems with dryness" at the Institute of Physical Geography and Geoecology. The influence of histosols on retention, especially in the National Park of Šumava, is a delicate topic because of collision of nature protection and valuable biotopes preservation on one hand and countryside utilization for anti-floods protection on the other hand. The thesis follows the bachelor thesis "Water retention of histosols". It includes a detailed pedological analysis of the basins of 'Rokytka' and 'Černý potok'. The result of the thesis is water retention determination in the basins and calculation of overall soil retentive potential. The thesis also addresses the analysis of the influence of organic soil on retentive potential of countryside. Keywords: water retention, histosols
Anthracological analysis of chernozems in Czechia
Danková, Lenka ; Šefrna, Luděk (advisor) ; Zádorová, Tereza (referee)
This thesis deals with a pedogenesis of chernozems in Czechia (Central Europe). It solves a problem with open landscapes in Central Europe, further a role of man and fires in formation of this soils and relation between colour of chernozems and the content of black carbon. In my thesis is represented pedoanthracology as a method, which can be useful for future study of open landscapes in Central Europe and for an influence of man. In this thesis, there were also analysed two chernozemic soils with Raman spektrometry. It was found out, that chernozems was probably formed under forest-steppe vegetation with residue of post glacial steppe. Anthropogenic activity and fires could be new factors of pedogenesis of Central European chernozems. It was showed a strong relation between colour and content of BC. Raman spectrometry found a presence of BC in our analysed soils.
Land evaluation of important prehistoric agricultural sites in Bohemia
Poništiak, Štefan ; Šefrna, Luděk (advisor) ; Dreslerová, Dagmar (referee)
The presented bachelor thesis deals with the land evaluation of 80 prehistoric archaeological sites. The aim of the thesis is comparison of evaluated land in the past and the present on the basis of suitable sources. Information about the past evaluation of land was drawn from the Theresian Czech cadastre and imperial imprints of maps of the stable cadastre. The present land evaluation is represented by maps of BPEJ and their evaluation points. The comparison of evaluated land in the cadastre of archaeological site on the maps of imperial imprints with one kilometre perimeter around the site is also included. The survey of literature characterises briefly the prehistoric eras and the diversified approaches to the land evaluation up to the present times. The result of the thesis is that the land evaluation is higher in the present on the basis of used research tools and methods. The land evaluation is lower in the immediate vicinity of the site. The effect of various factors on the results of the thesis is discussed at the end of thesis. Keywords: land evaluation, archaeological sites, BPEJ, perimeter of kilometre
Soil management of large investment projects on the example of the industrial zone Kolín - Ovčáry
Bejblová, Klára ; Šefrna, Luděk (advisor) ; Kuklík, Miloslav (referee)
The thesis deal with the soil sealing and the rehanding with the uncovering of soil cultural layers. This problem is describe on the example of the industrial zone Kolín - Ovčáry. In the thesis there is the evaluation of the soil characteristics and their changes in areas where due to the trensfer of the cultural layer was created completely new structure of soil cover compact of soil units with artificial stratigraphy of profile. For this area the new classification subsumtion is suggested. The overall impacat of the soilsealig and implementation of the uncovering of soil cultural layers, despite of local incerase of soil fertility parameters, we evaluate as the degradation of soil cover.

National Repository of Grey Literature : 102 records found   1 - 10nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.