Aarhus University Seal / Aarhus Universitets segl

Stream ecosystem and wetland processes

We investigate the effects of man-made stress factors, including climate change, on key ecosystem processes in streams and wetlands and how these are reflected in downstream lakes and fjords. Water and wetland ecosystems can be a key factor in regulating the runoff of nutrients from the terrestrial landscape and therefore play a major role in the eutrophication of downstream ecosystems. Furthermore, a number of ecosystem processes are central to the role of the streams in the carbon storage, which, among others, is important for the time postponement of the availability of organic matter and thus postponement of eutrophication. Our research includes key processes related to nutrient turnover and circulation/storage of organic matter in wetlands and streams, as well as how these processes are linked to the biological communities.

We work closely together with the Section for Aquatic Biology. We cooperate in projects on nutrient dynamics and ecosystem metabolism in lowland streams, factors controlling the biomass and composition of macrophytes in freshwater ecosystems, interactions between streams and wetlands, the spreading and colonisation of macrophytes and the ecology of Arctic aquatic mosses.

Ongoing projects within this topic

Water resources management under complex, multi-stressor conditions (MARS)

MARS
2014-2018. MARS has a particular focus on examining the overall effects of low water flow, nutrients and fine sediments on the biological structure and function. In our experiments, we investigate the influence of these stressors on the community structure of macroinvertebrates, phytobenthos and freshwater fungi and the interactions between these groups of organisms under the given stress scenarios. In addition, we examine how the ability of organisms to perform their ecological function is affected in these stress scenarios (e.g. metabolism, nutrient uptake and decomposition of organic matter). The project is financed by the Lundbeck Foundation.

New weed cutting methods

Press release (Danish)
2018-2021. Small streams make up about 75% of all Danish streams, and the weed cutting in these plays a very important role for both the drainage of agricultural land and for the ecological status of the streams. In the project we conduct experiments in 65 streams located in the municipality of Assens on the Danish island of Funen. The experiments include, inter alia, different methods and times of weed cutting. The aim is to examine how the water is best guided away from the surrounding farmland in such a way that the overall environmental status of the stream can be improved. The project is financed by Assens Municipality and Promilleafgiftsfonden.

Flooding impacts on Nature and farm land (FINA)

2018. Vejle Municipality is facing the need to implement climate adaptation measures so that the stream Vejle Å does not flood the city of Vejle. Upstream Vejle, in the Grejs stream valley, areas are identified which can be used to store water temporarily. Modelling of the flood regime is therefore necessary, including sediment disposal, which could have consequences for the conservation status of species and habitats in the area. At the same time, predicting the consequences of agricultural operations is required. The aim of the project is to document existing knowledge, including modelling of possible effects, and to describe the data that should be gathered so that politicians can make decisions on climate adaptation on a qualified basis. The project is financed by the Eit Climate-KIC, European Institute of Innovation and Technology.


Eksperiment looking at nutrient uptake in Gryde stream in Holstebro
Photo: Tenna Riis