INVESTIGADORES
DIEGUEZ Maria Del Carmen
artículos
Título:
Influence of precipitation, landscape and hydrogeomorphic lake features on pelagic 2 allochthonous indicators in two connected ultraoligotrophic lakes of North Patagonia
Autor/es:
C.QUEIMALIÑOS, M. REISSIG , MC DIÉGUEZ, M. ARCAGNI, S. RIBEIRO GUEVARA, L. CAMPBELL , C.SOTO CÁRDENAS, R. RAPACIOLI, M. ARRIBÉRE
Revista:
SCIENCE OF THE TOTAL ENVIRONMENT
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2012 vol. 428 p. 219 - 228
ISSN:
0048-9697
Resumen:
We investigated the terrestrial influence on two chained deep ultraoligotrophic lakes of North Patagonia (Argentina) through the seasonal analysis of two pelagic allochthonous indicators: i) water color, as a proxy of allochthonous dissolved organicmatter in lakes; and ii) the color to chlorophyll a ratio (Color:Chla), as an indicator of the relationship between allochthonous and autochthonous carbon pools.We also evaluated the potential transfer pathways of the allochthonous dissolved organic matter into the pelagic food webs of these deep lakes, including the natural zooplankton δ13C in the analysis. The dynamics of the allochthonous indicators were related to the precipitation regime,water level fluctuations, and hydrogeomorphic and catchment features of lakes Moreno East and Moreno West. The water color (absorbance at 440 nm) was extremely low (0.25 m  −1) in both lakes regardless of the season. However, precipitation and snowmelt regimes drove the increase and decrease ofwater color, respectively. A significant positive relationship between the zooplankton bulk δ13C with the water color would suggest an input of allochthonous organic carbon into the pelagic consumers. The incorporation of the dissolved allochthonousmaterial into higher trophic levels is likely favored by the behavior of planktonic organisms, feeding on mixotrophic flagellates and ciliates,which dominate the pelagic foodwebs of these Patagonian lakes.Morphometric aspects,mainly the higherwater residence time, led to lower values of allochthony inMoreno East compared toMorenoWest, probably accentuated by its upper position in the lake chain. Overall, our results suggest that these allochthonous signals can bring insight into the magnitude of the interaction between terrestrial environments and lake ecosystems, even in extremely clear and ultraoligotrophic systems, such as the Andean Patagonian lakes.