INIBIOMA   20415
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y MEDIOAMBIENTE
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Environmental changes affecting light climate in Andean Patagonian mountain lakes: Implications for the plankton community
Reunión:
Congreso; Global Change and the Worlds Mountains; 2010
Resumen:
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 their physical structure with co-occurring modification in the
surrounding vegetation. This 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.