Artículos de revistas
Mid-Late Holocene Climate and Trophic States in a Shallow Lake from the Southern Pampa Plain, Argentina
Fecha
2014-06Registro en:
Laprida, Cecilia; Plastani, María Sofía; Irurzun, Maria Alicia; Gogorza, Claudia Susana; Navas, Ana; et al.; Mid-Late Holocene Climate and Trophic States in a Shallow Lake from the Southern Pampa Plain, Argentina; PAGEPress; Journal Of Limnology; 73; 2; 6-2014; 325-339
1129-5767
1723-8633
Autor
Laprida, Cecilia
Plastani, María Sofía
Irurzun, Maria Alicia
Gogorza, Claudia Susana
Navas, Ana
Valero Garces, B.
Sinito, Ana Maria
Resumen
Changes in trophic status of the shallow Lake La Brava (southeastern Pampa plain of Argentina) are evaluated based on geochemical, biological and sedimentological data. Based on a conceptual framework, we propose that the lake level defines the water column mixing conditions, affecting internal lake processes and determining the transparency of lake water. The shift between alternative states is reconstructed for the last ~4800 years. Four main lake stages has been recognized, although short term shifts characterize all stages. A turbid phytoplankton-dominated state prevailed between ~4700-4500 cal yr BP. Drier conditions and low lake levels pushed the lake to a clear state until 2000 cal yr BP. Afterwards the lake switched back to a turbid state, and these conditions persisted until ~200 cal yr BP. In the last 200 years, the lake switched back and forth between a clear and a turbid state anew, the latter represents the modern conditions of the lake since ~1950 AD. These shifts can be attributed mainly to climatic drivers.