Management challenges related to long‐term ecological impacts, complex stressor interactions, and different assessment approaches in the Danube River Basin

Abstract

For centuries, rivers have experienced massive changes of their hydromorphic structures due to human activities. The Danube River, the second largest river in Europe, is a case in point for longterm societal imprint. Resulting human-induced pressures are a key issue for river management, aiming to improve the ecological conditions and guarantee the provision of ecosystem services.As the most international river basin in the world, the management of the Danube is particularly challenging and needs a well-organized cooperation of 19 nations. The recent river basin management plan has identified pollution and hydromorphological alterations as most pressing problems, but it has also acknowledged newly emerging issues. In this article, we present 3 specific exam- ----------------------------------------------------------------This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Principal threats to the conservation of freshwater habitats in the continental biogeographical region of Central Europe

“…Tierney et al (1998);Friberg et al (1998);Sievers et al (2017) Reforestation-it may be assumed that on balance the impacts of reforestation using native species should be positive for freshwater biodiversity in the . (2019);Bloom et al (2013);Abell et al (2019);Beltran et al (2011);Hein et al (2018) …”

Large rivers as complex adaptive ecosystems

“…This legacy of modification represents a challenge for the current management of these landscapes. The manuscripts by Hein et al () and Schletterer et al () provide examples of these challenges, whereas the study of O'Keefe et al () shows how a transdisciplinary approach has been employed to develop and implement sustainable environment flow regimes.…”

“…Management of the Danube is particularly challenging because it involves the cooperation of 19 nations. The Hein et al () manuscript outlines the development of the recent river basin management plan, which identified pollution and hydromorphological alterations as the most pressing problems, but it also highlights recent emerging issues that have arisen from the attempt to link the different assessment approaches based on the European legal frameworks to analyse the specific pressures at different spatial scales. These examples highlight the need for a more integrated approach in the management of large rivers that cross government boundaries and particularly for the future management of the Danube River Basin.…”

Long-Term Changes of Species Composition and Functional Traits of Epiphytic Diatoms in the Szigetköz Region (Hungary) of the Danube River

“…It has long served social and economic purposes (shipping, hydropower generation, irrigation, recreation, etc. ), still, it is a riverine ecosystem with good ecological potential [6]. A wastewater treatment program implemented in the early 2000s resulted in re-oligotrophization of the Hungarian section of the Danube, while the effects of global warming (rise in water temperature, altered water flow) also contributed to detectable changes in the riverine ecosystem [7].…”

“…Recently, a new water management problem emerged in the area related to both global warming and altered relationship between the river and groundwater as a consequence of Danube diversion [10]. Due to the altered water regime of the Danube (increasing difference between minimum and maximum water levels, increasing variability of water regime [6]), drying out of certain tributaries of the Lower Szigetköz floodplain is becoming more frequent during low water periods and wetland extent is gradually shrinking. As a result, lateral connectivity between branches is eliminated over time and water supply to branches is impaired.…”