Klement Tockner is a full professor for Aquatic Ecology at the Free University Berlin and director of the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), the largest freshwater ecology institute in Germany (www.igb-berlin.de). He received a PhD at the University of Vienna, and a titulary professorship at ETH. He has special expertise on freshwater biodiversity, ecosystem functioning, and river and wetland restoration and management. He is Editor-in-Chief of the journal Aquatic Sciences and Subject Editor of the journal Ecosystems. He has published more than 180 scientific publications including 100+ ISI papers. At present, he coordinates a large EC-funded project on freshwater biodiversity (www.freshwaterbiodiversity.eu). He is member of several scientific committees including the crosscutting group on freshwater biodiversity of DIVERSITAS. Within REFORM, Professor Klement Tockner and Professor Huib de Vriend (Deltares) are jointly responsible for the internal scientific quality control process.

1. Professor Tockner, what is your affiliation with rivers?

I have worked on river floodplains since the beginning of my career, mostly on large rivers and Alpine streams. During the past 15 years, I have had the great opportunity to study rivers in Africa, the USA, Japan, Australia, and several European countries. These experiences have broadened my view on river system functioning. In particular, I am interested in integrating the hydrogeomorphic, ecological, and social dimensions of river corridors. I have been involved in large river restoration programs where scientists and managers closely cooperated from the beginning on, for the benefit of both.

2. What are the greatest challenges at the moment in restoring rivers in Europe?

The major anthropogenic impacts, and the challenges, differ across Europe. River fragmentation, due to hydropower production, is critical in Northern Europe, pollution in Eastern Europe, channelization in Western Europe, and water scarcity in the Mediterranean area. There are, however, common challenges across the regions:

First, the non-deterioration principle of the WFD must be granted higher priority than the objective of achieving a good ecological status; restoration cannot compensate for the loss of the last free- flowing rivers. We are currently witnessing a rapid loss of the remaining free-flowing and near-natural rivers, for example in the Balkans but also in the Alps.

Second, it will be impossible to achieve good ecological status or even good ecological potential of all modified European rivers within the next 10 to 20 years. Therefore, clear priorities must be set for where restoration should be carried out, which measures are required, and when they should be implemented.

Third, we need to shift to a process-oriented approach in management by integrating geomorphic, hydrological, and ecological functions. Furthermore, we lack long-term data, in particular about the ecological conditions, which limit our ability to assess and forecast trends. A solid database is critical for successful restoration.

3. How can research contribute to addressing these challenges? What do you consider to be the importance of a EU-level project such as REFORM to improve the success of hydromorphological restoration measures?

One way to address these challenges is to focus on the key processes and landscape features. For example, vegetated islands, pivotal landscape elements that were once very common along all European rivers (and still are in many rivers), are among the first elements that disappear as a consequence of river and flow regulation. Remaining vegetated islands are usually in a more natural state than adjacent riparian areas, forming “nuclei” for restoration and conservation. However, the formation of vegetated islands requires space, a dynamic flow regime, and sediment and large wood supply. Another approach is to focus on succession processes. Biodiversity depends on a full range of succession stages, from bare gravel to mature forests. Research projects like REFORM can deliver good practice examples as well as a network of large restoration sites in order to establish the links between lessons learned from science and lessons learned from practice.

Photo: Artificial riffles in the Belgian - Dutch border stretch of the River Meuse were recently created to maintain groundwater levels in the adjacent Natura 2000 areas and enlarge local habitat diversity in the main channel

4. You are the coordinator of the EU-funded project BioFresh on freshwater biodiversity. Do you see commonalities between BioFresh and REFORM and ways for the two projects to connect?

These are highly complementary projects. BioFresh, which runs until April 2014, focuses on freshwater biodiversity (i.e. the response side), while REFORM´s focus is more on fluvial geomorphic aspects (i.e. the stressor side). In this sense, BioFresh and REFORM form a bridge connecting drivers and responses.

REFORM can benefit from the publicly available database that BioFresh is building. The compilation of a European biodiversity database allows the identification of priority areas for management. Such a tool is also required for the key stressors. Combining both databases would allow to identify areas that have the highest conservation value and restoration potential.

Additionally, BioFresh will produce an interactive Global Freshwater Biodiversity Atlas which might serve as a major information source for REFORM too.

5. How important is it for REFORM to be integrated in relevant (research) networks within Europe and beyond? To whom should REFORM connect to as priority?

In Europe, REFORM needs to connect to the implementation of the WFD, the Habitats and the Flood Directives, and to Sednet (the European Sediment Network). At the global scale, REFORM should explore links with GEO BON (Group on Earth Observations) and the Global Water System Project.

Among the great challenges in the water sector is the development of synergies among the currently competing objectives in agriculture, navigation, industry, and ecology. The discussion on the water-energy-food nexus must integrate waters as ecosystems too. Ecosystem services are currently used in a very narrow, simplified approach, purely from a human use perspective. Therefore, it remains a major challenge to manage rivers not just for the optimization of a few services but to consider intrinsic values and ethical aspects too. Otherwise, we will lose most of the rich biodiversity of rivers and floodplains within the coming decades.

6. What do you believe should be done to support the achievement of WFD objectives with regard to hydromorphology more effectively?

Despite major merits, there are limitations to the concept of the WFD:

First, using past reference conditions as a goal for future ecosystem management under rapidly changing environmental conditions is disputable. The question will not be “which organisms lived in a specific system”, but “which can live in the system”. Novel communities, a combination of native and non native assemblages that have no shared history, will dominate future ecosystems. We need to understand how novel assemblages form, what their ecological and economic consequences are, and how they should be managed.

Second, the WFD is based on a rather static view of rivers; a process-oriented approach is required for their future management.

Third, many restoration projects fail because they mainly focus on the channel but underestimate the functional linkages with the terrestrial and subsurface realms. Aquatic insects, for example, exhibit a higher mortality during the short terrestrial phase - when they emerge, disperse and mate - than during the larval stage. However, we have scant information about the various habitat requirements of organisms that have complex life cycles.

Last but not least, restoration efforts – in particular for heavily modified water bodies - will need to be complemented by, or perhaps even replaced by, increasing levels of management intervention, in order to create and maintain the desired ecological values of ecosystems. This includes the manipulation of the hydrology, the construction of artificial habitats, as well as combining technical with more natural systems.

Professor Tockner was interviewed by Eleftheria Kampa (Leader of Dissemination and Stakeholder Involvement of REFORM, Ecologic Institute) on 7 June 2012 in Berlin.

In the 2010 FP7 call for a research project on hydromorphology and ecological objectives of the WFD, the European Commission explicitly requested to make use of existing knowledge and expertise. REFORM has addressed this explicitly in its first and cross-cutting work package. The main aim is to make the state-of-the-art knowledge on hydromorphology, the interaction with ecology and wider environmental aspects timely available to support river basin managers while preparing the next round of River Basin Management Plans (RBMPs). The results will be made available through regular deliverables, but also through the REFORM Wiki. Early 2013 REFORM will organise an interactive stakeholder workshop to support science-policy and science-practice interfacing on hydromorphological degradation and restoration of rivers. The compilation of the existing knowledge in work package 1 will form the basis to discuss the scientific foundation and applicability and further ambitions of REFORM. This start of REFORM will support all subsequent tasks within the project by compiling and providing information on existing knowledge.

Figure Cross-cutting work package 1 synthesizes existing knowledge and expertise on hydromorphological degradation and restoration of rivers. The majority of its output is available early 2013

In more detail we will critically evaluate and analyse existing data (published and unpublished) on:

1. the linkages between river morphology and their underlying hydro-physics, hydromorphological and ecological variables and processes
2. the effects of hydromorphological restoration on these variables and processes
3. the socio-economic drivers and gains of hydromorphological alterations
4. the socio-economic constraints for, costs and benefits of hydromorphological restoration.

 This review will allow to analyse:

1. the biotic responses to environmental degradation
2. the effects of multiple pressures on various temporal and spatial scales
3. the first RBMPs on a European scale to identify knowledge gaps, develop and sharpen hypotheses

To meet these objectives, work package 1 is broken down into six tasks:

In task 1.1 we review and analyse the existing hydromorphological survey methods comparably to a similar analysis of the biotic assessment methods already performed within the EU project WISER. We hypothesise that existing survey methods are mainly focussed on the site and reach scales and do not sufficiently cover process-based characteristics. Based on the relevant bottlenecks for biota we will identify suggestions for additional metrics and variables will be developed (scheduled to be available by October 2012).

In task 1.2 we review and analyse the effects of pressures on hydromorphological variables and processes based on a typology of pressures developed within the IWRM-NET project FORECASTER. The main objective is identifying the most eco-hydromorphological relevant impacts across spatial and temporal scales (April 2013).

In task 1.3 we review the linkages of a set of core hydromorphological variables and variables describing ecological status and functioning. Response variables will include ecological status as measured by biological quality elements (fish, invertebrates, macrophytes, diatoms) and a set of functional parameters (self purification capacity, aquatic-terrestrial interactions, functional traits) and will be classified according to major physical processes, effect size and response time. We hypothesize that species tolerance thresholds are more relevant for addressing existing limitations for biota compared to habitat preferences (April 2013).

In task 1.4 we analyse the first RBMPs and Programmes of Measures in regard to eco-hydromorphology. It is a highly applied task to immediately provide knowledge for the drafting of the second RBMPs and Programmes of Measures. Gaps in knowledge and application of restoration measures will be identified and potential ecological improvements and drawbacks predicted (April 2013).

In task 1.5 we review and analyse the socio-economic drivers and effects of hydromorphological degradation and restoration, in particular focusing on the costs of hydromorphological degradation and on the definition and development of cost typologies. This task further compiles metadata of existing cost information on hydromorphological degradation (October 2013).

In task 1.6 we will manage the meta-data produced within REFORM. This task will provide data to the other work packages of REFORM.  The meta-database will help making the project results publicly available and providing a knowledge tool for all kinds of stakeholders, especially water managers.

In the past the River Narew (Poland) split into multiple, interconnected, coexisting channel belts, thus creating numerous backwaters and oxbows. Such river systems situated on alluvial plains are referred to as ‘anastomosing’ in scientific literature. They distinguish themselves by a dense network of belts of variable width and length which by turns split and join. The hydrological regime of the River Narew manifested itself by long lasting flooding and additional intensive inundation by shallow groundwater.

Photo: Grasslands in the regulated section of Narew (Tomasz Okruszko)

In the late 1970s, a reach of the River Narew between the village of Kolonia Rzędziany and the junction with the Biebrza River has been engineered. As a result, the network of multiple channel belts was replaced by one deep channel. The grasslands and meadows replaced the wetland ecosystems. Contrarily, the upstream part of the Narew River still consists of multi-channel riparian wetlands which in 1996 became a protected area called the Narew National Park (NNP; www.npn.pl). However, hydrological alterations in the regulated stretch led to the decrease of the groundwater level in the NNP favouring common reed expansion and shrubs encroachment causing a loss of ecosystem biodiversity.

In the early 1990s, the Polish Bird Protection Association (PTOP) initiated a project focused on restoration of partly natural conditions in a so called buffer zone i.e. between the park and intensive grasslands. First restoration works began in 1996 on the oxbows near the village of Rogowo. In the period 1996-2001 the oxbow lakes were cleared and the shrubs, mud deposits, reeds and their parts were removed. The next step was the construction of new river channels through the Rzędziany-Pańki dike (which is the border between park and grasslands) aiming to restore the multi-channel system. The first of two stone rapids in the main artificial channel was constructed in 2007 and the second was finished in 2010. The aim is to increase the water level in the downstream part of the park.  Farmers in the surrounding area have strongly protested against the construction of rapids. The area exposed to restoration works is situated in the northern part of the NATURA 2000 PLB200001 site called Bagienna Dolina Narwi (the Wetland Narew Valley) stretching between the villages of Kolonia Radule and Żółtki and covering ca. 13.4 km². This area is located on the downstream border of the Narew National Park.

Photo: Rapid increase of the water level in the buffer zone  (Tomasz  Okruszko)

The Narew National Park was founded in 1 July 1996. It is situated in the north east of Poland, in Podlasie Province, 30 km west from its capital, the city of Białystok. Its headquarters is located in the village of Kurowo. The Park covers 6,810 ha of the Narew 45 km long valley bottom between the villages of Suraż and Rzędziany. Within the NNP 98% of soils are permanently or temporarily inundated. The objective of the Park is to protect the wetland valley covered by alder carr, sedge and sedge-moss meadows.

The Narew River is one of the case studies of REFORM aiming to assess the interaction between restored stretches and the status of the wider catchment.