Quantitative food webs and invertebrates assemblages of a large River: a spatiotemporal approach in floodplain shallow lakes

VACCARI CARINA; CARVALHO, DEBORA; GIRI FEDERICO; COLLINS PABLO AGUSTIN; WILLINER VERONICA

MARINE AND FRESHWATER RESEARCH

CSIRO PUBLISHING

Lugar: Collingwood; Año: 2017 vol. 67 p. 1 - 15

1323-1650

n order to identify the spatiotemporal variation in the use of trophic resources and food web 21 attributes, we described the structure and composition of communities and examined the food 22 web in two shallow lakes over three hydrometric levels using the stomach contents of fishes and 23 decapods. The communities are more similar temporally, while the food webs are clustered 24 spatially. The drought phase was the most divergent in both cases with dominance of mussels and 25 prawns in the communities. The spatial variations of food web attributes are the result of higher 26 connectance and nestedness in the directly connected lake. Predators consumed macrophytes over 27 all hydroperiods though this predation was most intense during flooding pulse. Detritus was of 28 the greatest importance during the transition phase, while the use of basal resources was more 29 equitable during the drought period. Among invertebrates, the magnitude of trophic interactions 30 varied from the consumption of mayflies and midges in the flooding and transition phases to 31 mollusks, copepods and prawns in the dry season. The high consumption of macrophytes and 32 abundant invertebrates suggest the importance of autochthonous inputs into food webs and that 33 variation in food supply is a key factor for food web structure.