Naslov
Abundance and biomass responses of microbial food web components to hydrology and environmental gradients within a floodplain of the River Danube

Autori
Palijan, Goran

Izvornik
Microbial ecology (0095-3628) 64 (2012), 1; 39-53

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
bacterioplankton; heterotrophic nanoflagellates; phytoplankton; floodplain

Sažetak
This study investigated relationships of time-dependent hydrological variability and selected microbial food web components. Samples were collected monthly from the Kopački Rit floodplain in Croatia, over a period of nineteen months, for analysis of: bacterioplankton abundance, cell size and biomass ; abundance of heterotrophic nanoflagellates, and nanophytoplankton ; and concentration of chlorophyll a. Similar hydrological variability at different times of year enabled partition of seasonal effects from hydrological changes on microbial community properties. The results suggested that, unlike some other studies investigating sites with different connectivity, bacterioplankton abundance, and phytoplankton abundance and biomass, increased during lentic conditions. At increasing water level, nanophytoplankton showed lower sensitivity to disturbance in comparison with total phytoplankton biomass: this could prolong autotrophic conditions within the floodplain. Bacterioplankton biomass, unlike phytoplankton, was not impacted by hydrology. The bacterial biomass less affected by hydrological changes can be an important additional food component for the floodplain food web. The results also suggested a mechanism controlling bacterial cell size independent of hydrology, as bacterial cell size was significantly decreased as nanoflagellate abundance increased. 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

POVEZANOST RADA