Macrophyte assemblages in relation to environmental, temporal and spatial variations in lakes of a subtropical floodplain-river system, Argentina

MARCHETTI, ZULEICA YAEL; SCARABOTTI, PABLO

FLORA

ELSEVIER GMBH

Año: 2016 vol. 225 p. 82 - 91

0367-2530

tThis work analyses the variation in the structure of macrophyte assemblages in relation to environmen-tal (lake morphometry and water physico-chemistry), temporal and spatial variables, in seven floodplainlakes placed in the surrounding of the Salado and the Paraná Rivers confluence in the Paraná floodplain-river system. We recorded the variations in cover of thirteen of the most important macrophyte speciesamong rooted and free-floating life forms. A discriminant analysis of the main coordinates showedsignificant differences among floodplain lakes (spatial variation), as well as among the 13 months stud-ied (temporal variation). Redundancy analysis indicated that electrical conductivity, maximum depth,shoreline development index, lake area and water temperature had significant influence on macrophyteassemblages. In a partial RDA, environmental and temporal variables accounted for a similar percent-age of total explained variation (∼50%), whereas spatial variables, including distance to main channel,accounted for 30.6%. Results show that the environmental variables of lakes, temporal descriptors, and thespatial position of lakes along the floodplain can explain a significant fraction of variation of macrophyteassemblages. These results allow us to understand the dynamic of macrophyte assemblages along tem-poral and spatial scales and their association with flooding regime, considering local (physico-chemicaland morphometric) and landscape (spatial) characteristics of the floodplain environments.