National Repository of Grey Literature 104 records found  previous11 - 20nextend  jump to record: Search took 0.01 seconds. 
Changes of diversity and abundance of aquatic avifauna in relation to the physical-geographical environment
Adam, Matyáš ; Romportl, Dušan (advisor) ; Chuman, Tomáš (referee)
Changes of diversity and abundance of aquatic avifauna in relation to the physical-geographical environment ABSTRACT. This thesis looked into the issue of impact of changes of suitable habitat structure and climatic conditions, as the most discussed environmental factors, on model group of organisms - waterbirds. In the first part there was characterized effect of these factors on model group by the available literature. The relevant environmental variables were processed in the second part. For analysis of impact of these environmental factors on abundance and diversity of aquatic avifauna there were used data from International Waterbird Census in January term from 93 sites throughout the Czech Republic. Data were chosen for the period 1975, 1990 and 2006, in accordance with the database CORINE Land Cover. As multivariate data analysis there were used redundancy analysis (RDA) and mixed models with random effects, which showed significant associations with both weather conditions and other environmental factors. Selected environmental variables contributed substantially to the explanation of variability in species data, that was also tested suitability of their use. Keywords: physical-geographical environment, climate change, land cover, habitat structure, biodivesity, waterbirds
Forest soil acidification in the Czech Republic and analysis of differences between spruce and beech stands
Růžek, Michal ; Chuman, Tomáš (advisor) ; Romportl, Dušan (referee)
Forest soil acidification in the Czech republic and analysis of differences between spruce and beech stands Abstract Acidification of forest soils is the process which considerably affected soil chemistry in the 2nd half of the last century. The aim of this paper is to give comprehensive review about the soil acidification, especially with focus on differences between forest species Norway spruce (Picea abies) and beech (Fagus sylvatica). The work also provides information about acidification mechanisms and its historical development in the Czech Republic. In the practical part the soil conditions under the beech and spruce stands from 5 mountainous and upland sites are compared. The results showed better soil conditions under the beech stands, where higher pH values and concentrations of base cations were measured. However there were observed lower concentrations of toxic Al3+ in deeper horizons under the spruce stands, although the difference was insignificant. key words: soil acidification, spruce stands, beech stands, Czech Republic
Revitalisation of post-mining sites
Veselý, Martin ; Chuman, Tomáš (advisor) ; Matějček, Tomáš (referee)
This work introduces and compares some basic facts about recultivation and alternative methods of restoration, such is revitalization and natural succession. Recultivation is the way of quick revegetation, but it's expensive and in many cases contraproductive considering biodiversity of recultivated sites. Whereas, approaches based on principles of ecological restoration have many positives. They can create much valuable landscape structures and ecosystems than recultivation, and they enhance biodiversity and conservation of rare species.
Effect of environmental variables on diversity and abundance of water bird species
Adam, Matyáš ; Romportl, Dušan (advisor) ; Chuman, Tomáš (referee)
Effect of environmental variables on diversity and abundance of water bird species Abstract The environmental variables affect the abundance of species and individuals of most living organisms significantly. The intensity of environmental changes can be evaluated by using bioindicators. The birds rank among them. The most significant variables of the wide range of abiotic, biotic and anthropogenic factors are likely change of habitat structure and quality and climatic changes. In this thesis there is addressed issue of the impact of these factors in the model group of organisms - water birds. The first part is devoted to the characteristics of the impact of environmental variables on the abundance and species diversity of birds by the research of available literature. The relevant data are processed in the second part. There is carried out basic analysis of major environmental factors affecting the diversity and abundance of waterfowls at locations of interest. Keywords: environmental variables, climate change, land cover, habitat structure, biodivesity, waterfowls
Soil development in sand pits
Svačinová, Ilona ; Chuman, Tomáš (advisor) ; Eckertová, Sabina (referee)
It has not been paid enough attention to research of soil evolution in sand pit yet, so this study is focused on soil development in sand pit within primary succession. The study makes literary recherche of the most important factors which affect soil development. The study further detects volume of humus and soil pH in model area and how these attributes are changing in dependence on succession age. Differences of researches of pedogenesis in primary succession are discussed. Keywords: primary succession, sand pit, soil
Landscape changes due to suburbanization - an example of south-eastern outskirts of Prague
Paločková, Anežka ; Romportl, Dušan (advisor) ; Chuman, Tomáš (referee)
The study deals with the evaluation of landscape changes and ecosystem functions in the case study situated in the hintreland of Prague with the emphasis on the process of suburbanization. It analyzes the amounts, the range and the types of the changes of landscape due to suburbanization process and their effects on landscape structure and function. Landscape changes are evaluated using remote sensing and software ArcGIS, function and services of ecosystems are evaluated by modified Hessen method. Powered by TCPDF (www.tcpdf.org)
Extent and characteristics of alpine wetland in the Amazon River headstream area
Svoboda, Jan ; Chuman, Tomáš (advisor) ; Engel, Zbyněk (referee)
The Amazon River headstream was defined on the basis of the Hatun Mayu 2000 expedition results. It is the water catchment area of Apacheta and Carhuasanta streams down to their confluence in the Lloqueta River in the Cordillera Chila. The characteristic feature of these streams and their tributaries is the presence of the wetlands dominated by Distichia Muscoides. This plant here and elsewhere in the High Andean wetlands creates up to several meters of peat deposits. These deposits slow down and block waterways, causing wide wetland spreading. This specific alpine habitat, called bofedales, is crucial for the survival of a number of animal and plant species as well as for people living in these inhospitable areas. Defining these wetlands is one of the important steps to understanding what role these wetlands have in nature, as well as protecting them, as they appear to be very sensitive to environmental changes. Due to the isolation of the Amazon headstream the Remote Sensing Methods seem to be ideal for defining them. Keywords: Amazon River headstream area, bofedales, wetlands, remote sensing, NDVI, NDMI
The impact of urban sprawl on the environment.
Havel, Petr ; Chuman, Tomáš (advisor) ; Romportl, Dušan (referee)
The suburbanization process - a shift of population and activities from city centre to its fringe - is not only a socioeconomical phenomenon; city spatial expansion is a serious concern for an environment as well. The volume of suburban and sprawling areas is constantly increasing, moreover the character of this development is inefficient both spatially and energetically. A crucial changes take place in a landscape, which is being fragmented and homogenized. Those changes affect organisms, which live in the landscape; their natural environment is intensively modified and not all of them are able to get used to a newly created conditions and resist to a pressure of invasive species. A lot of compacted and impervious surfaces negatively influence not only the biota, but also a water quality, infiltration and water regime. Last but not least, new development seals a lot of quality agricultural land. Sealed soils are irreversibly deteriorated and become useless for further agricultural use. Despite the fact, that legislative in the Czech Republic should protect the high-quality agricultural soils, the study, made in the surroundings of D1 highway shows that's not the case. Two thirds of the commercial suburban development take place on the most productive and valuable soils. This number suggests poor...
Geographical origin of alien plants in the Czech Republic
Kopicová, Irena ; Chuman, Tomáš (advisor) ; Matějček, Tomáš (referee)
The topic of the proposed thesis is the geographical origin of non-native species of plants in the Czech Republic and it deals with non-native plants while identifying their phyto- areas. The causes of introduction, plant characteristics as well as ecological consequences, gains and dangers for the biodiversity in the Czech Republic are also assessed. The thesis is divided into two parts with first part dealing with a theoretical introduction in a form of a literary research on the geographic origin of non-original species of higher plants in the Czech Republic. Here, the basic terminology is discussed and so are specific issues. A chapter dealing with neo-phytes contains also a subsection on invasive plants, where it was necessary to stress their potential threat to ecosystems. Second part is devoted to the application of the topic in the education of geography by creating a work sheet and by defining main terminology for high school students. The aim is to encourage students to think about which plants are important, where they come from and why and how they reached us. Likewise, it is important that students could reflex on how non- native plants may affect the ecosystem in which they had been introduced.

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