The effect of hydrology and habitat diversity on cross ecosystem linkages in an alluvial floodplain

Outline

Floodplains are some of the most biodiverse ecosystems in Europe, but also some of the most threatened. Their high biodiversity is sustained by a high diversity of habitats and a tight coupling between riparian and aquatic ecosystems, through the exchange of ecological subsidies. Indeed, the riparian food web may be partially or fully reliant on the fluxes of emerging aquatic insects as a high-quality nutritional source. Further, the biomass and timing of emergence may strongly constrain the degree of cross-ecosystem coupling, yet these attributes may vary with local habitat conditions and thermal regimes.

Research aims

In this Masters project, you will characterize how floodplain hydrology and morphological diversity may constrain the incorporation of aquatic subsidies into the riparian food web. The project will take place in the Maggia river floodplain, in Ticino.

Research questions

You will characterize aquatic insect emergence during spring and summer across the floodplain. You will also characterize the communities of riparian arthropods and quantify the contribution of aquatic preys to their diet. You will investigate what factors drive the spatiotemporal variation in aquatic insect emergence and riparian arthropod communities, as well as the proportion of aquatic preys in the riparian food web (resources availability, phenological match, consumer traits etc). Finally, you will work in collaboration with the team of Prof. P. Molnar (ETHZ) and use their hydrodynamic models to predict how changes in minimum flows affect cross-ecosystem linkages.

Requirements

We are looking for a student interested in ecology, and with interest and experience in aquatic insect identification. A strong interest in field work is required and an ability to work long days outside in autonomy. Field work require weekly 2-day visits between April and mid-May, then biweekly or monthly visits until the end of September. The student should therefore be available for the project from early or mid-April 2024. A driving license is also necessary.

Supervisors?

The student will be based at Eawag in Dübendorf, and supervised by:

Dr. Pierre Chanut, Schweizerische Vogelwarte 
Email: (pierre.chanut@vogelwarte.ch)

Dr. Carmen Kowarik (Eawag) 
Email: (carmen.kowarik@eawag.ch)