Variabilidad espacial de macrófitas acuáticas con diferente contenido fenólico en la llanura aluvial del río Paraná Medio: relaciones con variables limnológicas

MAYORA, GISELA; SCHNEIDER, BERENICE; DOS SANTOS AFONSO, MARÍA

Azul, Buenos Aires.

Congreso; V Jornadas y II Congreso Argentino de Ecología de Paisajes.; 2015

Instituto de Hidrología de Llanuras "Dr. Eduardo Jorge Usunoff"

Objectives: evaluate phenolic content (PC) and species distribution of floating and emergent macrophytes in the Middle Parana system. Macrophyte leaves were sampled in floodplain environments to analyze PC and differences between species (Kruskal-Wallis). Species and limnological variables from 49 patches were evaluated with CCA. PC was significantly variable: Ludwigia peploides and Myriophyllum aquaticum showed the highest values. The first two CCA axes explained 22% of species variability, being dissolved nutrients, chromophoric dissolved organic matter (CDOM) and phytoplankton biomass the significant variables. Isolated environments were associated to CDOM, phytoplankton biomass, P, and high PC macrophytes; connected environments were associated to Si, N, and low PC macrophytes. We conclude that high PC species could be associated with isolated environments due to: nutrient competition (phenols are detrimental for competing primary producers); Si depletion (nutrient decreasing herbivory, as phenols). Furthermore, phenolics are CDOM precursors, being prejudicial to macrophytes which are not adapted to colored environments