Resumen

DORADOR, CRISTINA; PARDO, RODRIGO  y  VILA, IRMA. Temporal variations of physical, chemical and biological parameters of a high altitude lake: the case of Chungara lake . Rev. chil. hist. nat. [online]. 2003, vol.76, n.1, pp. 15-22. ISSN 0716-078X.  http://dx.doi.org/10.4067/S0716-078X2003000100002.

The Chungará lake (18º14' S, 69º09' W), the most austral and highest among the intertropical andean lakes, is located at 4,520 m of altitude. It is a polymictic system of tectonic-volcanic origin with a maximum depth of 34 m. It has a narrow temperature range in depth and seasonally (4-11 ºC), and which mean annual values show an increment in 1.2 ºC between 1986-1987 and 1998-1999 periods. The system total volume has reduced significatively (-6.58 %) during both periods of study and consequently in the maximum depth. Salinity has increased significatively, presenting maximum values of 1,464 µmhos and 2,650 µmhos, respectively. These changes would be modifying the phytoplankton composition and abundance and are also probably associated to the significative chlorophyll a decrease between these two periods (P < 0.0054).

Palabras llave : volume; temperature; salinity; phytoplankton.