Climate change affecting Periphyton primary producers in Andean North-Patagonian mountain streams: The effect of canopy on light availability

MARTYNIUK NICOLAS; MODENUTTI, B.; BALSEIRO, E.

Granada

Congreso; ASLO Aquatic Sciences Meeting; 2015

Association for the Sciences of Limnology and Oceanography

In the Andean Patagonian mountains, the structure of riparian canopy is dynamic and influences physical, chemical, and biological dimensions of streams and mediates a number of terrestrial-aquatic linkages. Canopy cover can vary over decades and longer time scales in association with the state of forest development, disturbance history, and climate. The variation on light availability has ecological consequences because directly affects the photosynthetic process in the aquatic primary producers. Consequently, the canopy affects the availability of light and determines the carbon (C) fixation and C: nutrient ratio of periphyton producers. In our study, we analyzed photosynthetic parameters and elemental composition in the periphyton of four streams with different canopy cover of Nothofagus forest. We found that the photosynthetic parameters and periphyton biomass in streams showed a bell-shaped relationship with light availability which is dependent on canopy cover. Also we anticipate that under a scenario of climate change, forests migration and their changes will modify the light availability affecting periphyton stoichiometry.