PIs: Dr. Vanessa Minden, Prof. Dr. Michael Kleyer

The Elbe is one of the major waterways of central Europe and is connected to many parts of Europe via an extensive network of shipping canals. The immense amount of cargo transported along the river has led to a massive transformation of both its riverbed and shore, with major implications on natural ecosystems. As important the Elbe estuary is as a waterway, it is not less important from an ecological point of view. It is characterized by strong variability and dynamics of e.g. salinity, tidal range and turbidity, and is inhabited by various brackish-water and estuary-endemic species, which makes it of special importance for nature protection. It has been recognized that a management towards a natural bank protection should be favored over an artificial embankment, provided that the economic use of the Elbe estuary for shipping and transportation of cargo remains assured (see e.g. BfG-project “Biogene Uferstabilisierung” and KLIWAS).

Natural vegetation along the estuary predominantly consists of reeds, including common reed (Phragmites australis), softstem bulrush (Schoenoplectus tabernaemontani) and saltmarsh bulrush (Bolboschoenus maritimus). Projects like KLIWAS (“Ästuarvegetation und Vorlandschutz”) and the BfG-Project “Biogene Uferstabilisierung” have evaluated the responses of reed vegetation on tidal influence, hydraulic stress and land use. They come to the conclusion that natural vegetation in some areas along the Elbe estuary delivers sufficient bank protection and recommend a combination of both artificial and natural bank protection.

The subproject “Plant trait responses to the environment and their effects on ecosystem properties” as part of the tibass project aims at the evaluation of the delivery of ecosystem services by the natural reed vegetation of the Elbe estuary in order to identify embanked areas suitable for restoring natural vegetation. For this, the responses of plant functional traits to environmental drivers (wave energy, sediment conditions etc.) and the effects of these traits on ecosystem services (wave attenuation) will be studied.

This subproject focuses on:

a) the responses of plant functional traits to environmental drivers (tidal range, inundation, salinity, nutrient availability etc.)

b) trait-trait interactions (allometric scaling relationships and trait-offs between traits)

c) the effects of plant traits to ecosystem functions (wave energy, sedimentation rates, productivity)

This project is in cooperation with Prof. Stijn Temmermann (University of Antwerp)

Project of bfg