Non-additive effects of multiple global-change drivers on aquatic ecosystems of both hemispheres

Abstract

Aquatic ecosystems worldwide are being exposed to an unprecedented number of alterations caused by the impacts of global climate change. Over the last decades an increasing amount of attention and effort has been given to examining the effects of these perturbations, however, existing studies reveal few consistent response patterns that allow us predicting and understanding how ecosystems will behave in the upcoming future under these ongoing alterations. The rationale behind these contrasting responses underlie in that most of these studies have been focused in study of the single impacts of these drivers, therefore neglecting the complexity of the natural environment.

Thus, the purpose of this doctoral dissertation is study the interactive effects of three of the main global change drivers (ultraviolet radiation [UVR], nutrient inputs and temperature) that are currently impacting the ecosystems. To achieve this objective, it was carried out a combination of long-term and remote-sensing data (i.e. atmospheric aerosols, surface solar irradiances and particulate organic carbon) together with a serie of laboratory and in situ experiments. The experimental studies performed considered both different combinations of global change drivers, different temporal scales (from hours to weeks), different levels of biological organization (from populations to ecosystems) as different ecosystems from both hemispheres (i.e., high-mountain lakes, coastal and open sea areas).