Naslov
Microbial responses to hydrology and environmental gradients within a floodplain of the River Danube

Autori
Palijan, Goran

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
5 th Croatian Congress of Microbiology with International Participation / Černi, Silvija ; Šeruga Musić, Martina ; Škorić, Dijana - Zagreb : Hrvatsko mikrobiološko društvo, 2012, 22-22

ISBN
978-953-778-05-7

Skup
Croatian Congress of Microbiology

Mjesto i datum
Primošten, Hrvatska, 26.09.2012. - 30.09.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
Bacterioplankton; heterotrophic nanoflagellates; microbial food web

Sažetak
The purpose of this study was to investigate responses in abundance and biomass of microbial food web components to natural hydrological variability of the free-flooding segment of the River Danube. Free exchange of water, nutrients, organic matter and biota between floodplain and the river have positive repercussions on its ecology, biodiversity and productivity. Development of bacterioplankton, nanophytoplankton and chlorophyll a concentration in this study were all negatively influenced by the flood pulse where chlorophyll a concentration was negatively affected already by the flow pulse. This to some extent indicates a smaller sensitivity of nanophytoplankton fraction to flood. Bacterioplankton and phytoplankton were stimulated by the isolation phase of the floodplain, while autotrophic components were also stimulated by environmental gradients. There was no dependence of bacterioplankton on nanophytoplankton abundance and chlorophyll a concentration which suggests the development of bacteria on sources of carbon other than phytoplankton. The results of this study support the reports of weak or no coupling of bacterioplankton and heterotrophic nanoflagellates in ecosystems with higher trophic status. This could be the consequence of indirectly proven top-down control of heterotrophic nanoflagellates. Preserved natural variation of connectivity of the floodplain with the river results with appearance of hydrology of the floodplain as a crucial factor in structuring microbial responses. Hydrology, regardless of seasonal sucession, has the potential to structure microbial food webs, supporting microbial development during lentic conditions. Conversely, other components appear unaffected by hydrology or may be more strongly controlled by biotic interactions. This research therefore adds to understanding of microbial food web interactions in the context of flood and flow pulses in river-floodplain ecosystems.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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