Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "temporal distribution" wg kryterium: Temat


Wyświetlanie 1-2 z 2
Tytuł:
Temporal changes of aquatic macrophytes vegetation in a lowland groundwater feed eutrophic course [Klatovske Rameno, Slovakia]
Autorzy:
Otahel'ova, H
Hrivnak, R.
Valachovic, M.
Janauer, G.A.
Powiązania:
https://bibliotekanauki.pl/articles/58642.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
diversity
botany
aquatic plant
vegetation
lowland eutrophic stream
ecological status
distribution
Slovakia
Klatovske Rameno
temporal change
Opis:
Klátovské rameno is the lowland slow-flowing groundwater feed eutrophic tributary of the Malý Dunaj River (Danube Plain), where our study of temporal changes of aquatic macrophytes vegetation was realised in 1999 and 2005. For survey of aquatic vascular macrophytes the Kohler’s method (Janauer 2003) was used, which is compliant with European standard EN 14184. Altogether 35 aquatic macrophyte species were recorded during the survey. Nuphar lutea persisted as the most dominant species in 1996 and 2005. Species diversity increased slightly after the nine years: ten species immigrated to the watercourse. The changes in species abundance have shown weak differences, however the abundance of Sparganium emersum has increased markedly. Alien species Elodea canadensis and both S. emersum and Hydrocharis morsus-ranae significantly enlarged their distribution in the stream. The ecological quality of the river, based on the aquatic macrophytes assessment criteria, was slightly impaired after nine years, but still 90% of its studied course has a high or good ecological status.
Źródło:
Acta Societatis Botanicorum Poloniae; 2007, 76, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temporal changes in the concentrations of zinc and cadmium in the sedimentary strata of Nozha Hydrodrome, Alexandria, Egypt
Autorzy:
Rifaat, A.E.
Ahdy, H.H.H.
Powiązania:
https://bibliotekanauki.pl/articles/48576.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
agricultural development
Alexandria
aquatic environment
cadmium concentration
Egypt
heavy metal
industrial development
Nozha Hydrodrome
sediment
sewage effluent
temporal change
urban development
vertical distribution
zinc concentration
Opis:
This study is concerned with the temporal changes in the levels of zinc and cadmium in the sediments of Nozha Hydrodrome during the past 100 years. Seven sediment core samples, covering the study area, were collected from the bottom of the Hydrodrome. A five-step sequential extraction technique was applied to determine the solid phase concentrations of zinc and cadmium. Zinc gives an idea of the quantities of sewage effluents, while cadmium provides an indication of the amounts of agricultural discharges. The vertical distribution curves show that the average total concentrations of zinc in the sediments increased at a rate of 2.5 μg g−1 y−1 from 1900 to 1950 and at 1.5 μg g−1 y−1 from 1950 to 1990. Since 1990 the zinc concentration in Nozha Hydrodrome sediments has been decreasing at 1.5 μg g−1 y−1. The average total cadmium concentration exhibits a different vertical distribution pattern: it increased at a rate of 0.42 μg g−1 y−1 from 1900 to 1950, after which it became constant from 1950 to 1970. Since 1970 it has been increasing at 0.53 μg g−1 y−1. The ongoing increase in cadmium concentrations in the sediments is due to the increase in agricultural discharges into the Hydrodrome, especially as significant amounts of phosphate fertilizers are used to nourish the soil around the Hydrodrome. The rise in cadmium concentrations since 1900 has been accompanied by a similar increase in zinc concentrations with time resulting from the discharge of untreated sewage into the Hydrodrome. In 1990 a sewerage system and sewage treatment plant came into operation, as a result of which discharges of domestic effluent into the Hydrodrome ceased. Since then the amount of zinc in sediments has been decreasing steadily.
Źródło:
Oceanologia; 2011, 53, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies