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Potravní zdroje bezobratlých v Ardovské jeskyni a v jeskyni Domica - předběžné výsledky
Nováková, Alena ; Elhottová, Dana ; Krištůfek, Václav ; Lukešová, Alena ; Hill, P. ; Kováč, L. ; Mock, A. ; Luptáčik, P.
The chemistry (organic matter content and pH) of different substrates from the Ardovská and Domica Caves in the Slovak Karst National Park (Slovakia) and the composition of their microbial communities were studied. Differences in organic matter content and microbial communities were found between the substrates from the Domica and Ardovská Caves. A broad spectrum of photoautotrophic microorganisms (algae and cyanobacteria) was found in different cave microhabitats (cave sediment, rotten wood, earthworms casts and isopods faeces), but no algae were detected in the fresh bat droppings and in the intestinal tract of the isopod .i.M. graniger./i.. Microfungi and bacterial colonies play the primary role in transforming bat guano into a food source for saprophagous and microphytophagous invertebrates.
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Změny ve společenstvech půdní mikroflóry a mesofauny během rozkladu listového opadu ve dvou vegetačních zónách - litter bag experiment
Jirout, Jiří ; Petrásek, Jiří ; Čápová, Lenka ; Farská, Jitka ; Jínová, Kristýna ; Rusek, Josef ; Krištůfek, Václav ; Elhottová, Dana ; Starý, Josef ; Nováková, Alena
The hypothesis, whether autochthonous species of soil biota are able to decompose litter from lower vegetation zones in higher zones, was tested by field trial. Litterbags with litter of beech (.i.Fagus sylvatica./i. L.) and/or oak (.i.Quercus robur./i. L.) were exposed in beech and spruce forest on the mountain Kleť (Protected Landscape Area Blanský les). Litterbags layout simulated vegetation zones shift to the higher altitude induced by global warming. There were used litterbags with three different mesh size (42 µm, 0,5 mm, 2 mm) for exclusion of certain parts of edaphon. Several changes of soil bacteria and micromycetes, oribatid mites, springtails and gamasid mites were studied during two years of exposition. There were exposed 480 litterbags at the start of the experiment (November 2002). After 2, 4, 6, 12, 24 months of exposition parts of all litterbags were recovered. Immediately after the sampling litter pH(KCl), moisture and mass loss were measured.
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Potential sources of polyunsaturated fatty acids for saprophagous soil invertebrates
Elhottová, Dana ; Frouz, Jan ; Krištůfek, Václav ; Lukešová, Alena ; Nováková, Alena ; Tříska, Jan
Main sources of important nutritionally compounds - polyunsaturated fatty acids (PUFA) essential in soils animal diet were compared. The highest concentration of PUFA was found in cyanobacteria (namely Antarctic strain Pseudophormidium sp.), followed by fresh litter, algae, fungi and decomposed litter. The PUFA occurrence in bacteria including actinomycetes was rare. Leaf litter is the most important source of PUFA for soil invertebrates in regards to both PUFA concentration and occurrence in soil. The stage of litter decomposition significantly affected the content of all 13 detected PUFA. The total PUFA content decreased significantly during litter decomposition. Enrichment in certain PUFA was observed in the latest stages of litter decomposition, indicating that the soil microflora improves the nutritional value of the decaying ĺitter.
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Quantitative and qualitative changes of phenolic compounds in alder leaf litter
Elhottová, Dana ; Vrchotová, Naděžda ; Tříska, Jan ; Krištůfek, Václav
Quantitative as well as qualitative changes of phenolic compounds were investigated in different decomposition stages (I-IV) of native alder leaf litter. The Folin-Ciocalteau method was applied for the determination of total phenolic compounds and the reserved phase HPLC for the determination of the phenolic acids. Both values decreased in dependence on stage of litter decomposition. The reduction of the total phenolic compounds and the phenolic acids was 20% and 50%, respectively, in the most decomposed litter (stage IV) in comparison with fresh litter (stage I, 100%). The ratio of free (simple extracted) and bound phenolic compounds (extracted after acid hydrolysis) in the group of total phenolic compounds and phenolic acids was determined. The characteristic feature of the fresh litter (stage I) was higher amount of the free phenolic acids as well as higher ratio of the free phenolic compounds to the bound ones. The following stage II was characterised by two times higher portion of free to bound total phenolic compounds in contrary to phenolic acids where the bound acids dominat ed over the free ones. Higher level of bound to free compounds in both observed phenolic groups was typical for the most decomposed litter samples (stage III and IV).In addition, the stage III and IV were characterised by new compounds, which were formed in the litter during its decomposition and were not detectable in the previous stages (I,II).
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The effects of cultivation conditions on polyphenol compounds levels in potato tubers periderm in varieties differing in their susceptibility to common scab
Krištůfek, Václav ; Diviš, J. ; Dostálková, I.
Field and glasshouse trials were performed in 2000 and 2001 to estimate total polyphenol contents in 15 potato cultivars from two sites that differed in the level of scab incidence. Polyphenol content was determined spectrophotometrically by Folin-Ciocalteau reagent at a wavelength 765 nm in tuber peelings of cultivars less and more susceptible to common scab. The polyphenol content of tuber peeling was influenced by cultivar, site, year and age of tuber periderm and was not influenced by maturity. The highest polyphenol content was observed in potato cultivars less susceptible to the scab. Regression analysis showed that negative relation occurs between polyphenol content and potato scab incidence (P=0,006). The polyphenol content significantly decreased during vegetative period.
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