MODEL FOR METABOLISM · Effects of pulse events at different spatial and temporal scales on stream ecosystems

Final Activity Report Summary - MODEL FOR METABOLISM (Effects of pulse events at different spatial and temporal scales on stream ecosystems)

The initial objectives of the Marie Curie postdoc fellowship 023053 were: i) to evaluate stream ecosystem stability to disturbances at different spatial scales; ii) to develop a new numerical routine to estimate stream metabolism; and iii) to determine how global climate change induced alterations of the flow and thermal regime might affect carbon fluxes. In order to analyse the ecosystem stability to floods at different spatial scales, stream ecosystem metabolism and stream community structure (aquatic invertebrates and algae) were measured during a year in 7 river segments in the Thur River basin, Switzerland. Results from the Thur River basin are being analysed conjointly with an equivalent data set from a semi-arid river basin in the southwest US, and are expected to be published by the end of 2009 or beginning of 2010. A new numerical routine based on the variation of dissolved oxygen was developed and validated in an additional field experiment in the Lutteren River, Switzerland. The developed routine, as well as guidance on how to properly quantify carbon fluxes in stream ecosystems has been already published and are expected to have a major impact on future studies of carbon fluxes in stream ecosystems. A river network model was developed to simulate carbon dynamics. This model was validated with empirical data and then used to simulate the processes of export and processing of organic carbon in river networks under different conditions of flow and temperature. Accordingly, simulations were performed for different scenarios in terms of flow and thermal regime, as well as in terms of the amount of lentic water bodies such reservoirs in the river network. Results from these simulations pointed out the predominant role of flow extremes in shaping the carbon dynamics at the river network scale and are expected to foster studies on the effect of flow on the carbon dynamics. These were however not the only achievements during the Marie Curie postdoc fellowship, as new research lines rose during the course of the work. The new research lines focus on two aspects, the thermal regime in stream ecosystems and the effect of increasing intermittency in headwater streams. Three studies have been performed in relation to the temperature regime in rivers and have been already published, while the work on intermittency is an ongoing project and publications are not likely to appear before the end of 2010. Overall, the 2 years period supported by the Marie Curie fellowship was useful to acquire new technical skills, especially in relation to modelling, to subsurface hydrology and to mesocosmos research. It gave me the opportunity to establish different interdisciplinary collaborations and resulted in 14 publications (already published or in the process of publication), as well as in a tenure-track position in a research centre.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз