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Ecological requirements of the critically endangered species \kur{Sedum villosum}
PRŮŠOVÁ, Monika
Hairy stonecrop (Sedum villosum) belongs to the group of plants that are endangered by real risk of extinction. If appropriate measures are not soon undertaken, it may disappear from the territory of the Czech republic. Preparation of an action plan should be a prerequisite for undertaking such measures. The aim of this diploma thesis was to verify ecological demands of this critically endangered species. I tested the effects of soil acidity and shading on seed germination and growth of hairy stonecrop plants in experimental conditions.
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An experimental study of initial succession on different substrata: analysis of changes in plant species cover and some soil biological parameters and their relationships
KRESÁČ, Martin
A four year experimental study of initial stages of succession on different substrata (sand, peat and gray clay overburden from brown coal mining) was carried out. The substrata were transplanted into two different landscape types in the Czech Republic. Control plots were filled with autochthonous topsoil treated with high temperature vapor. Plots with un-treated autochthonous topsoil were also established. Plant species cover and several soil-biological parameters (soil microbial biomass, basal soil respiration, exchangeable pH(KCl), organic-C extractable by potassium sulfate solution, and nitrate-N content) were measured once a year. Obtained data were mainly processed by unimodal (plant cover data) and liner (soil-biological data) ordination methods. Biological species traits (life span, seed dispersal vector, seed bank type, ecological strategy type following Grime, life form following Raunkiaer) were used to characterize early stages of plant succession. Vegetation and measured soil-biological parameters, except pH(KCl), were significantly changing during four growing seasons. Variance partitioning analysis based on plant species cover data indicated the landscape type to be the main governing factor and physico-chemical characteristics of substrate to be less important during the studied initial stages of succession. The same analysis based on soil-biological parameters showed the reverse result. Great variability of plant species ecological traits was noticed during four growing seasons. The earliest plant colonizers were mainly ruderal, anemochorous terophytes with persistent seed bank. The number of species with C-strategy type increased during the study. The relationship between the average plant species cover and measured soil-biological parameters was also examined during the experimental study of early succession. Direct and indirect ordination revealed the average sum of plant species cover to be weakly positively correlated with soil microbial biomass, basal soil respiration, nitrate-N, potassium sulfate extractable organic-C, metabolic quocient (qCO2) and negatively correlated to exchangeable pH(KCl). The relationship was significant only in the case of microbial biomass and potassium sulfate extractable organic-C. More detailed studies of the relationship between aboveground plant species biomass and soil microbial communities in initial stages of succession are required. Comparability of presented study is limited because not many experimental investigations of similar kind have been presented until now.
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Spring fen vegetation in west Bohemian spring fen area
LABURDOVÁ, Jitka
This thesis is about vegetation and water chemistry of thirty spring fens in West Bohemia. The aim of this work is to find out if there are any relationships between vegetation and water chemistry in the studied area. To investigate it, at each locality one fytosociological relevé of size 4 x 4 m was made and in autumn was taken one water sample.
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