MODENUTTI Beatriz Estela
congresos y reuniones científicas
Environmental changes affecting light climate in Andean Patagonian mountain lakes: implications for the plankton community.
B. MODENUTTI,; E. BALSEIRO,; BASTIDAS NAVARRO, M.,; M. S. SOUZA,; C. LASPOUMADERES,; F. CUASSOLO,
Congreso; Global Change and the World?s Mountains; 2010
In North-Patagonian Andean lakes (both alpine and deep subalpine) the very low concentrations of DOC lead to high UV exposure levels. In these lakes, the thermal structure, together with the low nutrient concentrations and the high UV transparency exert a strong effect on the composition and function of plankton communities. Here we analysed a dataset of lakes from the Patagonian Andes located between 750 m and 1700 m a.s.l. discussing the changes in their optical characteristics and the effect on plankton communities. Stratification depth can alter the light supply to phototrophic plankton since the deepening of termocline, which increases thickness of the mixing layer, can drag down planktonic organisms to low light level. Variations in glacial melt can also alter the plankton distribution in particular the deep chlorophyll maxima. Temperature is expected to increase in alpine areas in the next years, thus alpine lakes from the region (> 1600 m a.s.l.) will change physical structure with co-occurring modification in the surrounding vegetation. These changes may occur in a scenario were anthropogenic deposition of nitrogen was not recorded, therefore increase in carbon:nutrient ratios may be enhanced in the region.