National Repository of Grey Literature 64 records found  beginprevious55 - 64  jump to record: Search took 0.00 seconds. 
Antropogenní tlaky na stav půd‚ vodní zdroje a vodní ekosystémy v české části mezinárodního povodí Labe: Změny eutrofizace povrchových vod v povodí Labe a jejich vliv na stav společenstva fytoplanktonu
Výzkumný ústav vodohospodářský T.G. Masaryka, v.v.i., Praha ; Desortová, Blanka
Stručná informace o analýzách vzorků odebraných na vybraných úsecích. Analýzy zahrnovaly stanovení koncentrace chlorofylu-a, biomasy vybraných skupin autotrofních mikroorganismů Labe, Jizery a Vltavy. Stanovení biomasy skupin autotrofních mikroorganismů zastoupených ve fytoplanktonu bylo prováděno pro sinice a rozsivky. Pro vyhodnocení změn v toku Labe byly vybrány výsledky z let 1996-1999 a 2006-2009, které se týkaly koncentrací N-NH4, N-NO3, celkového P a obsahu chlorofylu-a. Porovnání fytoplanktonu a zooplanktonu proběhlo v menším časovém úseku. Byly zjištěno výrazné snížení koncentrací N-NH4, N-NO3 a celkového P. Nebyla zjištěna odlišnost v koncentracích chlorofylu-a. Druhové složení fytoplantonu je na rozdíl od složení zooplanktonu velmi pestré. Zooplankton neomezuje rozvoj fytoplanktonu.
Anabaena - Phenotypic and genotypic diversity of planktonic strains in fishponds and reservoirs of the Czech Republic
ZAPOMĚLOVÁ, Eliška
Morphological diversity of 61 Anabaena populations of 13 morphospecies was described under the field conditions of Czech fishponds and reservoirs. Polyphasic approach was then applied in classification of 45 clonal strains isolated from those populations. Detailed morphological analyses were performed and partial 16S rRNA gene sequences were obtained for 33 of the strains, and secondary metabolite production was evaluated in 20 strains. Plasticity of morphological characteristics under varied conditions of light, temperature, nitrogen and phosphorus was studied in selected strains, as well as their temperature and light growth requirements. The results were then discussed with respect to the delimitation of single Anabaena morphospecies. A new genus Sphaerospermum was defined for the morphospecies Anabaena kisseleviana, A. reniformis and Aphanizomenon aphanizomenoides, whose phenotypic and genotypic features differed considerably from all other Anabaena morphospecies. Unique information was provided on the occurrence and distribution of A. reniformis and Aph. aphanizomenoides in the Czech Republic.
Analysis of phytoplankton pigments from freshwater systems.
ŽIŠKOVÁ, Eva
The aim of this study was to use pigments to determine freshwater phytoplankton composition . The samples were collected from freshwater lakes in the Czech Republic and Germany. The pigment analyses were conducted using the High Performance Liquid Chromatography (HPLC). The HPLC data were processed by computer program CHEMTAX to calculate the composition of phytoplankton. The obtained pigment data were compared with standard light microscopy which was used to obtain more detailed taxonomic resolution.
Spatial heterogeneity and seasonal succession of phytoplankton on a longitudinal gradient in the Římov reservoir
RYCHTECKÝ, Pavel
Spatial distribution and seasonal succesion of phytoplankton along the longitudinal axis of a eutrophic Římov reservoir was investigated in 2007. Inflow, transitional and lacustrine zones were distinquished in the reservoir according to physical, chemical and biological parameters. Using a functional group concept, typical phytoplankton assemblages were found.
Alien, invasive and expansive species of cyanobacteria and algae in county Jihlava
MELICHAR, Antonín
The phytoplankton from 30 water reservoirs in county Jihlava was sampled during the year 2007. Species composition and relative abundance of species was studied and abiotic factors like pH, conductivity, temperature and dissolved ions were measured. High attention was paid to an appearance of alien, invasive and expansive species of algae and cyanobacteria. Literature search about alien species of diatoms in the Czech Republic was compiled.
Verification of Applicability of the CE-QUAL-W2 Model for Simulation of Phytoplankton, Epiphyton and Macrophyte Growth in Lipno Reservoir
ŠÁMALOVÁ, Klára
Verification of applicability of the CE-QUAL-W2 model for simulation of phytoplankton, epiphyton and macrophyte growth in Lipno Reservoir was tested. The model was first calibrated for the year 2004, then was applicated to the whole investigated period from 1.1. 2000 to 31.12. 2005. Sensitivity analysis was executed for mean growth parameters of phytoplankton, periphyton and macrophytes.
Modelování hydrodynamiky a kvality vody v dimiktické nádrži – nádrž Jordán, Česká republika
Hejzlar, Josef ; Jarošík, Jiří ; Borovec, Jakub ; Růžička, Martin
The two-dimensional, dynamic model CE-QUAL-W2 was used to model water quality of a small, highly eutrophic reservoir with intensive nutrient cycling between the water column and bottom sediment. The model was calibrated and evaluated for a 4-year, hydrologically variable period and used in a scenario simulation study to analyse effects of the changing external and internal phosphorus loading and depth of outflow to trophic conditions and water quality. The reservoir hydrodynamics were simulated with good precision in all parts of the seasonal cycle and during the whole period. Water quality and nutrient cycling could be calibrated and simulated with satisfactory results for individual years, however, an extrapolation of model to conditions with different nutrient loading was problematic. It spite of this partial limitation, the model was found appropriate for water quality evaluation and prediction in Jordan Reservoir.
Restoration of aquatic ecosystem and water quality in the drinking-water reservoir Římov after the flood in 2002
Hejzlar, Josef ; Kaštovská, Klára ; Seďa, Jaromír ; Znachor, Petr ; Jarošík, Jiří ; Haider, Z.
The extreme flood event in the catchment of the Malše River in August 2002 markedly changed hydrodynamics of Římov Reservoir (loss of thermal stratification; water residence time dropped from months to single days) and caused problems in water treatment due to a long-lasting increase in concentrations of dissolved organic matter. However, biota of the aquatic ecosystem was influences relatively little. Although large proportions of phytoplankton and zooplankton biomasses were flushed out of the reservoirs the originally dominant species re-established in their original size of biomass within less than one month. The fish community was influenced almost negligibly except for a temporal enrichment by species from streams and fishponds. These results evidence that the reservoir ecosystem is very stable towards fluctuations of hydrologic conditions.

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