Abstract
The particulate organic carbon (POC) is an important energy source present in the food chain of detritivorous fish. Considering its importance, this study aimed to investigate the effect of the flood pulse on the composition of the POC in a neotropical floodplain. For this, we analyzed the seasonal variations of the carbon isotopic composition (δ 13 C) and nitrogen (δ 15 N) in two different hydrological periods in the years 2000 and 2009. Sampling of potential sources of primary producers, as well as the POC, was held in different subsystems of the floodplain of the upper Parana river (subsystems of the rivers Parana, Baia and Ivinheima). In 2000, there were significant differences on isotopic signature (δ 13 C) of the POC, unlike what was seen in 2009, where the values of δ 13 C were depleted us three subsystems, and showed significant differences both in the Parana and Baia rivers. As this isotopic variation was attributed to the presence of flooding in 2009, that may be incorporated into new sources of the ecosystem. This is contrary to what was observed in 2000, when they were filled with recorded values below 3.5 m fluviometric. Thus, it can be concluded that the flood event has an effect on the composition of POC and therefore can directly influence the structure of fish food chains scavengers of the basin.
Highlights
Most medium-to-large rivers have adjacent floodable areas, which along with the main channel, are called river-floodplain systems (JUNK et al, 1989; NEIFF, 1990)
This study aimed to evaluate the effects of the flood pulse in a neotropical floodplain on particulate organic carbon (POC) isotopic composition in years with distinct hydrological cycles (2000 and 2009), mostly aiming to understand the structure and functions of the food webs
A significant difference was found between periods in 2009, for the Paraná (H1,8 = 5.33; p = 0.02) and Baía (H1.8 = 5.33; p = 0.02) rivers
Summary
Most medium-to-large rivers have adjacent floodable areas, which along with the main channel, are called river-floodplain systems (JUNK et al, 1989; NEIFF, 1990). In these systems, one prevailing ecological model is the Flood-pulse Concept (FPC), which states that the hydrologic pulse is the major. 411-419, Oct.-Dec., 2014 have a high habitat heterogeneity and maintain a considerable biodiversity of aquatic and terrestrial organisms (AGOSTINHO et al, 2004) According to these authors, the flood pulse in this area is still the main force regulating community structure and functions of this ecosystem. The overflow of the river in a floodplain should increase habitat area, availability of allochthonous resources, and should supply water enrichment thanks to nutrients transported from adjacent areas or the organic and inorganic material flooded (AGOSTINHO et al, 2004)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
