National Repository of Grey Literature 68 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
You cannot step into the same fishpond twice - an evolution of fishpond ecosystems to hypertrophy
Vrba, Jaroslav ; Benedová, Z. ; Jezberová, Jitka ; Matoušů, Anna ; Musil, M. ; Nedoma, Jiří ; Pechar, L. ; Potužák, J. ; Řeháková, Klára ; Šimek, Karel ; Šorf, M. ; Zemanová, J.
Shallow manmade fishponds in south Bohemia were used for fish production for centuries, however, their ecosystems have changed dramatically due to excessive nutrient loading and fish stocking. Preliminary results of ten sampled fishponds suggested their hypertrophic status at present, while their plankton structure and dynamics reflected the actual size/age class of fish stock consisting predominantly of common carp. Planktivorous fish (both young carp and whitefish) remarkably reduced abundance, size, and species diversity of crustacean zooplankton, in particular large daphnids, whereas larger carp itself did not cause such a strong top-down effect. All other plankton components, i.e. phytoplankton, bacteria, protists, and rotifers showed rather high abundance and diversity, and suggested a reasonable impact of various microbial processes and interactions in the recent hypertrophic ecosystems.
Hydrobiological monitoring of Medard Lake in 2017
Hejzlar, Josef ; Nedoma, Jiří ; Znachor, Petr ; Seďa, Jaromír ; Peterka, Jiří
The report summarizes the results of hydrobiological monitoring of Medard Lake 2017 and contains recommendations for further research activities. At the beginning of 2017, the lake was almost full, and at the end of March the last 30 cm water column was filled from the Ohře river. The ecosystem of the lake has reached its final nutrient load, which will be characterized by low levels of carrying capacity with low productivity planktonic and fish communities and specific seasonal changes in chemistry and biological parameters.
Hydrobiological monitoring of Medard Lake in 2016
Hejzlar, Josef ; Borovec, Jakub ; Nedoma, Jiří ; Znachor, Petr ; Seďa, Jaromír ; Peterka, Jiří
Presented report summarizes the results of hydrobiological monitoring of Medard Lake in 2016 and recommends further monitoring actions. Between November 2015 and June 2016 final flooding from river Ohře took place, resulting in enrichment of the lake ecosystem by large amount of nutrients at the beginning of vegetation season what affected seasonal development of chemical as well as biological parameters, from phytoplankton to fish.
The influence of nutrient loading, meteorological and hydrological conditions and operating manipulations on phytoplankton in the water suply reservoir Římov.
Hejzlar, Josef ; Jarošík, Jiří ; Nedoma, Jiří ; Seďa, Jaromír ; Znachor, Petr
Analysis of data collected during long-term and complex limnologic monitoring of the Římov reservoir in the period 1983 – 2015, which depict the development of physico-chemical conditions, hydrology and hydrodynamics of the reservoir with links to biological data on phytoplankton, zooplankton etc. showed that the concentration and species composition of phytoplankton depend on the supply and availability of nutrients, but are also influenced by climatic and hydrological conditions and water management operation of the reservoir.\n
Hydrobiological monitoring of Medard Lake in 2015.
Hejzlar, Josef ; Borovec, Jakub ; Nedoma, Jiří ; Znachor, Petr ; Seďa, Jaromír ; Peterka, Jiří
Presented report is summarizing the results of the hydrobiological monitoring of Medard Lake in 2015 and recommends further monitoring actions. In 2015 the lake was not flooding from river Ohře, therefore the water level increase was realized only by precipitation and inflow from lake’s own drainage area. Furthermore, it was the first year without stocking of maraena whitefish and brown trout.
Dynamic Contact Problems in Bone Neoplasm Analyses and the Primal-Dual Active Set (PDAS) Method
Nedoma, Jiří
In the contribution growths of the neoplasms (benign and malignant tumors and cysts), located in a system of loaded bones, will be simulated. The main goal of the contribution is to present the useful methods and efficient algorithms for their solutions. Because the geometry of the system of loaded and possible fractured bones with enlarged neoplasms changes in time, the corresponding mathematical models of tumor’s and cyst’s evolutions lead to the coupled free boundary problems and the dynamic contact problems with or without friction. The discussed parts of these models will be based on the theory of dynamic contact problems without or with Tresca or Coulomb frictions in the visco-elastic rheology. The numerical solution of the problem with Coulomb friction is based on the semi-implicit scheme in time and the finite element method in space, where the Coulomb law of friction at every time level will be approximated by its value from the previous time level. The algorithm for the corresponding model of friction will be based on the discrete mortar formulation of the saddle point problem and the primal-dual active set algorithm. The algorithm for the Coulomb friction model will be based on the fixpoint algorithm, that will be an extension of the PDAS algorithm for the Tresca friction. In this algorithm the friction bound is iteratively modified using the normal component of the Lagrange multiplier. Thus the friction bound and the active and inactive sets are updated in every step of the iterative algorithm and at every time step corresponding to the semi-implicit scheme.
Hydrobiological monitoring of Medard Lake in 2014
Hejzlar, Josef ; Borovec, Jakub ; Nedoma, Jiří ; Znachor, Petr ; Seďa, Jaromír ; Peterka, Jiří
Presented report is summarizing the results of the hydrobiological monitoring of Medard Lake in 2014 and recommends further monitoring actions. In 2014 the lake was not flooding from river Ohře, therefore the water level increase was realized only by precipitation and inflow from lake’s own drainage area. Forming of fish stock was realized according to stocking plans.
Hydrobiological monitoring of Medard Lake in 2013
Hejzlar, Josef ; Borovec, Jakub ; Nedoma, Jiří ; Znachor, Petr ; Seďa, Jaromír ; Peterka, Jiří
Presented report is summarizing the results of the hydrobiological monitoring of Medard Lake in 2013 and recommends further monitoring actions. In 2013 ongoing flooding of the lake from river Ohře had the main effect on the monitored parameters affecting the overall trophic level and having the cascading effect through the trophic pyramid.
Methodology for assessing ecological potential of heavily modified and artificial water bodies
Borovec, Jakub ; Hejzlar, Josef ; Znachor, Petr ; Nedoma, Jiří ; Čtvrtlíková, Martina ; Blabolil, Petr ; Říha, Milan ; Kubečka, Jan ; Ricard, Daniel ; Matěna, Josef
Methodology for the assessment of the ecological potential of heavily modified and artificial water bodies was developed, including water body typology. The selection of indicator metrics was based on statistical analyses of the sensitivity of each of the indicators towards the most significant stressor – eutrophication. According to these results, biological communities and their indicators were selected to comply with the requirements set forth in the Water Framework Directive (2000/60/EC).

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See also: similar author names
1 Nedoma, J.
3 Nedoma, Jakub
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