"Global warming has altered and will further alter the temporal patterns of the water temperature in stream ecosystems. These changes in the temperature patterns include an increasing frequency and magnitude of heat waves, as well as an alteration of the diel temperature patterns, with warmer night-time temperatures. A growing number of studies are assessing the effect of a mean temperature increase in the ecology of weatlands, forests, streams and other ecosystems, but the effect of the alteration of the temporal patterns is mainly unexplored and might have a major impact on the C balance of streams. Any change in the C balance in streams will be reflected in the global C balance given the connecting role of river networks between donor terrestrial ecosystems and sink marine ecosystems. In this research project, I aim to experimentally assess the effects of the alteration of the previously mentioned temporal temperature patterns on the stream C balance. Thus, 2 different types of mesocosmos will be assembled and used within the framework of this research. Expected results might help better understanding how global warming influences the C cycle at both ecosystem and global scales."