Gertrud Haidvogl

ABSTRACT The project "Vienna’s Wood" brought many new insights towards a better understanding of the largely unregulated Viennese Danube floodplains in river morphological, aquatic/vegetation ecological, forestal and environmental historical perspective. The results allow answering the following research questions: 1. What annual erosion and aggradation rates were typical for the river-floodplain system of the Viennese Danube prior to regulation? 2. Which riparian vegetation communities were typical for the Viennese floodplain and which successional/age stages did they show? 3. Which timber yield could theoretically be expected based on the historical site conditions (site age, hydrological conditions, ...) and how large are the differences in yield compared to today's regulated/stable floodplains? 4. How much wood was annually mobilized due to the erosion by the Danube River? (dead wood) 5. How big was the annual consumption of (fuel)wood in Vienna in comparison to the timber resources in the riparian forests and which proportion of required biomass could be met by local resources? 6. Which conclusions can be drawn from the historical analysis for an ecologically favorable and sustainable management of Danube floodplains under the current changed natural and socio-economic conditions?

This thesis deals with the development of Austrian riverine landscapes in the 19th and 20th centuries. The period covers expanding hydropower use as well as systematic river channelization and flood protection, enabling a risk-minimized establishment of permanent settlements in natural floodplains. This fundamentally altered natural river characteristics, transforming the formerly extensive riverine landscapes with regularly flooded zones into today's channelized running waters. Some floodplains were already colonized in the later Middle Ages, and agriculture and forestry were the dominant land uses for centuries. Up until the 19th century, buildings were erected almost only for commercial hydropower production. Over the last 200 years the demographic development required considerably larger land surfaces for settlements, especially around urban centres. Floodplains were particular target areas. The expansion of municipalities towards the rivers demanded systematic river regulat...

Zusammenfassung Auen sind ein wichtiger Teil des Ökosystems Flusslandschaft. Ihre Ausdehnung und ökologische Funktionsfähigkeit haben vor allem in den letzten 200 Jahren durch die zunehmende menschliche Nutzung stark abgenommen. Die Kolonisierung von Flussauen ging Hand in Hand mit einem grundlegenden Wandel im Hochwasserschutz. Dieser Artikel beschreibt anhand des Beispiels der Traisenflusslandschaft im Bereich der Stadt St. Pölten die parallel verlaufenden und sich gegenseitig beeinflussenden Prozesse von Landnutzungsänderung, Siedlungsentwicklung und Ausbau technischer Hochwasserschutzmaßnahmen. Im räumlichen und zeitlichen Verlauf der Siedlungsentwicklung St. Pöltens in den Traisenauen waren Industrialisierung, Urbanisierung, städtische Planung und technische Hochwasserschutzpraktiken treibende Faktoren. Die Stadt dehnte sich im 20. Jahrhundert kontinuierlich in die Traisenauen aus. Diese Expansion beschränkte sich zunächst auf die Ränder des HQ100-Abflussraums, während entlang ...

The temporal dynamic of riverine ecosystems and their fish communities and populations has been addressed in ecological theory and management for several decades. A growing number of case studies on the historic development especially of European and North American rivers have been published. Nonetheless, a theoretical debate about the contributions and limits of historical approaches and interdisciplinary co-operation is lacking. This article presents a brief overview of the role of history in river and fish ecology and suggests historical ecology as a scientific field that can offer a framework for future research. Based on case studies compiled in this special issue on the "Historical ecology of riverine fish in Europe", we draw conclusions on long-term changes of fish communities, on fisheries, aquatic ecosystem management and past habitat alterations and the potential of archaeological remains and written sources to study them. We discuss how modelling of historical f...

The modeling of the historical floodplain vegetation presented here is based on historical data and expert rules adapted from long-term field experience in recent floodplains. Historical maps and archive data were used to model the floodplain topography, age of vegetation stands, depths of the groundwater level, inundation frequencies and soil conditions of the entire Viennese Danube floodplain in 1825. This information, combined with expert knowledge about the autecology of the species, enables reconstructing the historical floodplain vegetation types.

... Gabriele Weigelhofer 1,3 , Alfred P. Blaschke 4 , Gertrud Haidvogl 2 , Severin Hohensinner 2 , Walter Reckendorfer 3 , Karl Reiter 3 , Bernd Schuh 5 , Thomas Hein 1,2 Keywords: restoration management, multi criteria decision aid, hydrological modelling, ecosystem modelling ...

RÉSUMÉ Que savons-nous de la productivité naturelle des forêts alluviales des grands fleuves avant les travaux de régulation à la fin du 19eme siècle ? Quelle était leur importance en termes de ressources et de source d'énergie ? Ces modèles historiques (pré-aménagements) peuvent-ils être utilisé pour définir des objectifs en termes de gestion durable des forêts alluviales actuelles ? Une équipe interdisciplinaire composée de géomorphologues fluviaux, d'écologues forestiers et d'historien environnementaux a étudié la dynamique des paysages fluviaux dans la région de Vienne (Autriche) au début du 19 ème siècle (1825). L'objectif était de reconstituer la production annuelle potentielle de bois avant les travaux de chenalisation. Nos modèles de reconstitution des forêt alluviales et les sources historiques ont montré que la production naturelle de bois dans ces plaines alluviales était supérieure à celle observée dans des forêt alluviales actuelles quasi-pristine. Cepen...

In this article, we investigate the changing role of the Danube river in relation to urban resource use, transport and land use for the case of 19th and early 20th century Vienna. Vienna makes a good case study due to its geographical position as a continental city and its dynamic development of population numbers and transport infrastructure in the 19th century. We trace the amount of energy used in the city and identify a shift from a biomass-based energy supply to the large-scale use of coal. Along with this shift went a change in the Danube’s role as transport route: while until the 1870s, the Danube was the most important freight transport route, river transport lost importance after the great Danube regulation in 1874, and the railway took over. The river was the most important route for providing fuel wood well into the 19th century: Vienna drew wood from remote areas situated upstream along the Danube to the West of the city. Only after the railway connection to Northern coa...

Contributing Authors and Commentators: Barben Daniel, Cont in Marco, Cut ura Marij a, Domany Bruno, Dorondel St efan, Egner Heike, Gaj ski Goran, Garcia-Sant os Glenda, Gueorguiev Tzvetel in, Hart l Mart ina, Hein Thomas, Hudecz Ferenc, Ivan Oana, Jelen Igor, Jungmeier Michael, Kopl iku Bresena, Laci Sabri, Lenhardt Mirj ana, Tamáska Mát é David, Mihalca Andrei, Miho Aleko, Papp Leila, Pet rovic Ana, Pont Didier, Pop Ana-Maria, Popova Jul iana, Sandu Crist ina, Sendzimir Jan, Šmid Hribar Mat ej a, St oica Georget a, St öglehner Gernot , Tabakovic Momir, Terzic Aleksandra, Torkar Gregor, Žlender Vita, Zoj er Hans

Land uses affect flood risks in various ways. The comparative analysis of the historical and current land cover/uses helps to better understand changing flood regimes. Based on historical cadastre maps from 1826 to 1859, the land cover/uses in the Austrian catchments of the rivers Rhine, Salzach and Drava were reconstructed to almost the level of exact plots of land. Catchment-wide analysis reveals a six-fold expansion of settlement areas, a decline of arable land by 69% and a shrinking of the formerly glaciated areas by 73% until 2016. In the Alpine fluvial corridors, i.e. flood-prone areas at the valley floors and valley sides at ca. 300-year floods, settlements even expanded 7.5-fold, severely increasing the potential for flood damages. At the same time, the overall channel area of running waters has been reduced by 40% and 95% the formerly large wetlands have been lost. Overall, the fluvial corridors were truncated by 203 km2 or 14%, thereby reducing flood retention capacity. Th...

River systems have undergone a massive transformation since the Anthropocene. The natural properties of river systems have been drastically altered and reshaped, limiting the use of management frameworks, their scientific knowledge base and their ability to provide adequate solutions for current problems and those of the future, such as climate change, biodiversity crisis and increased demands for water resources. To address these challenges, a socioecologically driven research agenda for river systems that complements current approaches is needed and proposed. The implementation of the concepts of social metabolism and the colonisation of natural systems into existing concepts can provide a new basis to analyse the coevolutionary coupling of social systems with ecological and hydrological (i.e., 'socio-ecohydrological') systems within rivers. To operationalize this research agenda, we highlight four initial core topics defined as research clusters (RCs) to address specific system properties in an integrative manner. The colonisation of natural systems by social systems is seen as a significant driver of the transformation processes in river systems. These transformation processes are influenced by connectivity (RC 1), which primarily addresses biophysical aspects and governance (RC 2), which focuses on the changes in social systems. The metabolism (RC 3) and vulnerability (RC 4) of the social and natural systems are significant aspects of the coupling of social systems and ecohydrological systems with investments, energy, resources, services and associated risks and impacts. This socio-ecohydrological research agenda complements other recent approaches, such as 'socio-ecological', 'socio-hydrological' or 'socio-geomorphological' systems, by focusing on the coupling of social systems with natural systems in rivers and thus, by viewing the socioeconomic features of river systems as being just as important as their natural characteristics. The proposed research agenda builds on interdisciplinarity and transdisciplinarity and requires the implementation of such programmes into the education of a new generation of river system scientists, managers and engineers who are aware of the transformation processes and the coupling between systems.

River systems are among the world's most threatened ecosystems, facing multiple and often interlinked pressures across different spatial and temporal scales (Best, 2019; Tockner, Pusch, Borchardt, & Lorang, 2010; Vörösmarty et al., 2010). With increasing population growth, industrialization, and the intensification of land use during the last century, both the variety of demands and the intensity of uses have increased, while ecological integrity, functioning, and biodiversity of riverine landscapes have declined (Ferreira, Globevnik, & Schinegger, 2019). The subordination of multiple ecosystem services provided by pristine river-floodplain systems to a few dominant anthropic uses has reduced the multifunctionality of these ecosystems severely (Parsons et al., 2017). Today, river managers face the challenge of considering a variety of social, economic, and ecological demands simultaneously and objectively, where policy and human attitudes and perceptions may hamper the acceptance of management measures (Dunham et al., 2018; Jähnig et al., 2011). Thus, future management and restoration need to recognize river landscapes as socio-ecological entities, which provide ecosystem services for humans based on their ecological integrity. The 6th Biennial Symposium of the International Society for River Science (ISRS) was hosted by the Institute of Hydrobiology and Aquatic Ecosystem Management at the University of Natural Resources and Life Sciences, Vienna (BOKU), Austria, from September 8–13, 2019. According to the conference theme “Riverine landscapes as coupled socio-ecological systems,” the symposium emphasized integrative research on the sustainable use, management, and protection of aquatic ecosystems. Particular attention was given to the complex interactions between society and the ecological functioning of highly modified riverine landscapes. This special issue of River Research and Applications includes 16 articles from this meeting, which address various challenges and solutions relating to the management and restoration of river-floodplain systems in the face of changing environmental and climatic conditions and increasing complexity of ecological and socio-economic demands. The articles span a wide range of topics, from the hydro-morphological development of river systems to the consideration of social aspects and complex abiotic–biotic interactions in river management, thus highlighting the need for process-based, dynamic, and integrated approaches in river management. 2 | THEMES OF THIS SPECIAL ISSUE

The present state of the Austrian Danube, its landscapes and its fish fauna is the result of many human interventions. These happened partly only in recent decades, but some also date back centuries. In the new book "Österreichs Donau. Landschaft – Fisch – Geschichte" ("Austria's Danube. Landscape – Fish – History") the authors persue the exciting question how the ecosystem of the Danube River and its floodplain has changed over time and how it can develop in the future. Besides the various human interventions in form of river regulations, construction of hydropower plants and their effects on the fish fauna, also the geological and fish ecology development throughout the whole Danube Basin are described. Previously implemented revitalization measures and proposals for a comprehensive ecological improvement of the river landscape with humans as part of the Danube habitat show the future potential of this great European river. Extensive illustrations with old ...

Integrated sustainable development is the new guiding vision in river basin management. This means that anthropogenic impacts on river systems are evaluated not only in sectoral terms with respect to their effects on the river itself, but also in integrative terms regarding the whole river landscape as a living space for man. This article presents a method of assessing the ecological, social and economic impacts of planned measures. This allows those measures to be selected from a number of possible scenarios whose implementation will have the better effects on the diverse functions of the river landscape.

The 350-km-long Austrian Danube river section has been changed dramatically by channelization in the 19th century and hydropower plant construction since the 1950s. A research project on the alluvial Machland floodplain (Upper/Lower Austria) is currently striving to reconstruct former habitat turnover (structural habitat regeneration and succession) of the Danube river-floodplain system based on the analyses of historical sources between 1715 and 1991.