For the first time ever, uniform freshwater experiments are carried out across Europe. During the course of this year, a start will be made on a series of experiments in streams along the Atlantic coast from Sweden to Spain. At the same time, a continental series of experiments will start in lakes between Sweden and Turkey.
The experiments are part of a European research project examining nature’s reactions to climate change. The stream experiments were devised and designed by Alterra, the Wageningen UR research institute for our green living environment. Alterra itself will run the stream experiments planned in the Netherlands and Germany.
Large-scale field experiments of this kind have never been attempted before. The ‘trans-Europe’ approach is also new: every country is carrying out exactly the same experiments and recording exactly the same data. The experiments focus on three of the main factors in climate change that affect water: changes in temperature, water flow and nutrients. As part of the stream experiments, in 2011 and 2012 by-passes will be constructed to allow sections of streams to stagnate and dry up. This is designed to measure the effects of summer droughts as predicted to occur in Europe in the next decades.
European framework project
The initiator of the stream experiments is Piet Verdonschot, freshwater ecologist at Alterra. Verdonschot has been conducting national and international research in streams and on climate change for many years.
The project for which this experiment was devised is a European framework project (FP7), entitled Adaptive strategies to Mitigate the Impacts of Climate Change on European Freshwater Ecosystems (REFRESH). ‘Here at Alterra, we have a great deal of knowledge on the effects of climate change on freshwaters throughout Europe,’ says Verdonschot.
‘Until now, most of our European research was carried out via field measurements and models. But I wanted to exclude the unpredictable and circumstantial factors that often occur when monitoring field conditions, so that we can generate much more uniform results that will be mutually comparable across Europe. Controlled field experiments are the best way to achieve this.
It is not common practice these days as it is relatively expensive and difficult to implement logistically at large scale. But it is, however, vital if we want to achieve significant and reliable results.’
The approach in this European wide experiment ensures that all the participating countries design the same experiment in their region and collect exactly the same information, thereby enabling the researchers to make accurate comparisons. The project will ultimately result in a system that will allow water managements to take effective measures to protect their freshwaters against negative effects of climate change. The framework project is being carried out by 25 European research institutes.
Dutch version involving seven Water Boards increases the chance of success for European Water Framework Directive
Ten Dutch restored streams will be closely monitored over the next few years. The majority of the streams Verdonschot has selected for his field experiments are streams that are already undergoing a process of re-meandering, which means that relatively few changes need to be made and costs can be kept to a minimum. He found seven Water Boards willing to help with the experiments by putting additional measures in place within current re-meandering restoration projects. Many of the additional measures are simple, but present a good chance on a successful restoration of the stream ecosystems that meets the demands of the European Water Framework Directive for the ecological quality of inland surface waters. ‘The Water Framework Directive water quality assessments for streams show that at present, many streams fail to meet one or more of the criteria,’ explains Verdonschot. ‘The current re-meandering projects take action to alter the shape (morphology) or the flow (hydrology) of the stream, but rarely do both at the same time. The novel approach adopted in the experiments combines different measures, and makes it possible to create an optimum combination of shape and flow.’ Additional measures include positioning dead wood in the streams to safeguard the variation in flow and to create a wider winter bed, which will serve as extra water storage and reduces the force of spates.
The Dutch streams where these experiment already have been started are the Egelbeek, the Hierdensche Beek (Waterschap Veluwe), the Hagmolenbeek (Waterschap Regge & Dinkel), the Reusel (Waterschap Dommel), the Tungelroyse Beek (Waterschap Peel & Maasvallei) and the Gasterense Diep (Waterschap Hunze & Aa’s). Later this year, Verdonschot’s team will make a start with the Lunterse Beek (Waterschap Vallei & Eem), the Jufferbeek (Waterschap Regge & Dinkel) and the St Antonuisloop (Waterschap Aa & Maas). Utrecht University and Wageningen University will strengthen the project with their terrestrial-ecological and hydrological expertise, respectively.
More information: Website REFRESH