|
|
Ontogeny of soldier behaviour and its polyethism in termites
Homolka, Petr ; Šobotník, Jan (advisor) ; Frouz, Jan (referee)
The presence of soldier caste is an important synapomorphy of group Isoptera. The adaptation of this caste to defense tasks is more than obvious and some of their morphological or even behavioral adaptations can be quite impressive. The polyethism in termites is relatively well known inbetween rather worker caste. If there are such a studies pointing at polyethism in soldiers, they are connected with soldier polymorphism. The morphological differences are of course important stimulus to role separation. The goal of this thesis was to examine the polyethism in the species of the termite with monomorphic soldiers - Prorhinotermes simplex. I did behavioral experiments with it in enclosed arenas, recorded on specific days. The data shows, that there are differences inbetween individuals and it would be benefical to invest further time to subsequent studies. The thesis bring out new point of view to defensive behaviour of termites and suggests, that even termite species without polymorphic species may have soldiers with different tasks. Besides I managed to map ontogeny of soldier behaviour in the first two weeks after moulting from presoldier instar. Key words: Isoptera, polyethism, soldiers, ontogeny, defensive behaviour Powered by TCPDF (www.tcpdf.org)
|
|
|
Influence of microbial community diversity on the decomposition of organic matter
Vicena, Jakub ; Frouz, Jan (advisor) ; Cajthaml, Tomáš (referee)
Microbial diversity plays an important role in the decomposition of soil organic matter. However, the drivers of this dependence still remain unclear. The work is based on long-term monitoring of soils of different successional stages of different diversity. Soil sampling was conducted on two dumps after brown coal mining in the Sokolov. Soils were X ray sterilized and inoculated by inoculum from both soils in two inoculation density which create gradient of microbial diversity. Then microbial respiration was measured in either supplied or not supplied by litter of Calamagrostis epigejos. Results showed a strong positive correlation between the microbial diversity and decomposition of organic matter if the microbial community is limited by available carbon. If there isn't carbon limit available, the decomposition rate is controlled by the amount of microbial biomass. Results demonstrated positive correlation between the rate of decomposition and the amount of fungal biomass. The soils with the addition of leaf litter showed priming effect in the initial stage of decomposition. In the control samples without addition of litter priming effect wasn't observed. Increasing humidity led to increase of decomposition rate. We can conclude with a clear conscience that similarly conclusive results associated...
|
|
|
Model of spontaneous vegetation development in post-mining heap
Vodička, Jan ; Frouz, Jan (advisor) ; Brůna, Josef (referee)
Predictability of primary succession in post-mining sites is needed for choosing appropriate restoration method. This study models 18 years of spontaneous succession on a post mining heap in Sokolov in the Czech republic with using historical aerial photographs and spatially - analytical methods. Each photograph has been georeferenced and classified manually into several categories based on the tree density. Three spatial models that applied different population growth equations and seed diffusion from the near neighbourhood has been developed. All models were able to predict spatial distribution of trees with solid accuracy, however, predictability were decreasing with time. The best results corresponded with 40% agreement on average from all years and more than 50% for some individual years. Keywords: spontaneous succession, spatial models, post-mining sites
|
|
|
Spontaneous establishment of woody vegetation in post mining heaps near Sokolov
Reitschmiedová, Erika ; Frouz, Jan (advisor) ; Hendrychová, Markéta (referee)
Surface coal mining heavily disrupts vast areas of landscape. Previous studies conducted in these areas reveal that succession processes on unreclaimed sites support close to nature community. It's crucial to understand and be able to predict these processes in order to include spontaneous succession into restoration plans. The aim of my thesis is to clarify establishment and dispersion mechanisms of dominant pioneer woody species willow (Salix caprea), birch (Betula pendula) and aspen (Populus tremula). Study carried out on unreclaimed sites on a large colliery spoil heap near the town of Sokolov. I have studied establishment and growth of pioneer woody species on both graded and ungraded sites, representation of individual woody pioneer species was on sites in different distance from the edge of the spoil heap, birch's population age structure and reproduction potential of willow in accordance to age. All pioneer woody species establish and grow better on ungraded sites. The amount of willow decreases while the number of aspen individuals remains the same and the amount of birch increases with growing distance from the edge of the spoil heap. Birch's population age reveals establishment of new individuals in favourable climatic conditions. Willow is reproductively capable at the age of 10 years...
|
|
|
The influence of the dominant trees and grain substrate the composition of the microbial community studied by PLFA
Stachová, Sandra ; Frouz, Jan (advisor) ; Heděnec, Petr (referee)
The aim of the thesis was to analyze soil microbial communities of three ecologically different locations, about 25 years old, forestry reclaimed dumps in the Republic of Poland, namely dumps of brown coal mine Bełchatów and sand mines Piaseczno and Szczakowa. I evaluated the degree of dependence of structure and composition of these communities on various substrate grain sizes and the influence of the dominant tree species. These were stands of birch (Betula pendula), pine (Pinus silvestris), oak (Quercus robur) and alder (Alnus glutinosa). Analysis of soil microbial communities was made by evaluating specific phospholipid fatty acids (PLFA) of microorganisms. It is the most appropriate way to implement the relatively rapid analysis of large numbers of samples, since PLFA are easily extractable and act as biomarkers indicating the presence of a number of different microorganisms (fungi, G- and G + bacteria, Actinobacteria, etc.) and thus allowing a qualitative and quantitative assessment of whole microbial communities. PLFA analysis enables to detect a total concentration of PLFA only in living soil microbial biomass. I analyzed 66 soil samples, 33 from an Oe layer and 33 from an A layer, every in three replications, i.e. three replications were collected at each location below each tree...
|
|
|
Using of soil microstructure in study of soil fauna bioturbation in post mining sites
Suchá, Linda ; Frouz, Jan (advisor) ; Tajovský, Karel (referee)
The paper follows up on previous analyses of changes in soil microstructure in the process of soil development on dumps around Sokolov, Czech Republic, using the soil thin section method. The distribution of structures in the topsoil of the profile was studied in two chronosequences, one overgrown with spontaneous vegetation and one reclaimed by alder planting. A comparison with historical data obtained at these locations 10 years ago was used, and, therefore, the same methods were also applied (Frouz et al., 2007b). The most distinct trend in the process of soil development over time, as observed through both a comparison of soil thin sections from various areas of chronosequence and changes in particular sites over time, is a gradual reduction of purely mineral structures and their replacement by organic matter - litter and its fragments, faecal pellets of arthropods, earthworms coprolites, and roots. This is illustrative of a high share of biogenic structures and a fundamental contribution of organisms to forming topsoil, a fact also pointed out by other authors. Keywords: Soil macrofauna; Soil microstructure; Soil thin section; Reclamation; Post-mining sites; Soil development; Earthworms
|
|
|
The effect of artificial drainage on the flow of water and other ecosystem functions
Kešner, Michal ; Frouz, Jan (advisor) ; Šír, Miloslav (referee)
The aim of this thesis is to summarize the current knowledge about the changes of soil caused by the subsurface tile drainage. It also deals with a uestion of the influence on other parts which are closely connected, as water, atmosphere and organisms. Foreign and domestic literature suggests that tile drainage by accelerates discharge from the watershed decreases groundwater level and drainage water influences the quality of surface water. It also changes the structure of soil, mainly reducting and anaerobic processes are replaced by oxidative and aerobic ones and all these decrease the amount of soil organic matter. Leaching of nutrients is observed from soil to drainage water. Original ecosystem changes and the composition of organisms shifts as well. But the biodiversity of location does not have to be affected. However, a reducing value of betadiversity may appear in broader context, community composition of original wetland is getting closer to surrounding ecosystems eventually. Due to close connections of all parts of the system, an impact on climate can occur. Knowledge achieved during the development of this thesis should be used in the research about the impact of tile drainage near village Senotín.
|
|
| |
|
|
Invertebrate succession on open coast coal post mining sites in response to the type of restoration
Hromádková, Šárka ; Reif, Jiří (advisor) ; Frouz, Jan (referee)
This review deals with development of invertebrates on sites after brown coal mining in response to the type of restoration. When the soil properties are improved, it is then necessary to mitigate negative threats such as landslides and erosion or low pH. The following is an overlap of fertile soil. Soil characteristics can be locally modified by diversifying of plantations of fast and slow growing wood species. After a succession of plants and the subsequent increase in litter layer, the development of the soil biota, responsible for decomposition of organic matter, begins. Soil macrofauna, espe- cially earthworms, mixes organic and mineral soil layers and thus contributes to the formation of humus. The work describes the migration, settlement and interactions (competition, food network) of invertebrates between themselves and in relation to the surrounding environment where they develop. The combination of open patches with the planting trees creates a diverse habitat, supports nutrient regime and variable and microclimatic conditions, which hosts a high diversity of invertebrates. Deciduous trees host a greater diversity of invertebrates than softwood. When planting, it is preferable to use deciduous trees because they produce easily degradable litter. Terrain depressions, such as layered belts,...
|
|
|
Spontaneous succession and its role in vegetation recovery of post mining sites and other disturbed areas
Dobešová, Alena ; Frouz, Jan (advisor) ; Mudrák, Ondřej (referee)
Ecosystem restoration is vitally important, to return ecosystem in acceptable stage after anthropogenic disturbance. Spontaneous succession when disturbed area spontaneously recovers over time can be also considered as restoration method. This will restore vegetation cover, the interactions between biotic and abiotic components of the ecosystem, energy transfer, nutrient cycling and other important functions. In this thesis, I examined the influence of environmental variables on the cover of vegetation during succession. It was a mean annual temperature, mean annual precipitation, pH and soil types. The optimal course of succession appears to be a large increase of coverage at an early stage and its basically unchanged trend in other stages of succession. This was achived with an average annula temperature of 7řC, with an annual rainfall of 900 mm at pH 5 and the light and heavy soils. Key words: spontaneous succession, vegetation recovery, vegetation cover, disturbed areas
|
guest ::
