Suchergebnisse

The purpose of this study is to evaluate the potential of restoration of a stream section. The starting point of the multiple-step assessment process was a historical analysis, which resulted in the definition of different sections within the study area, providing a base for the further restoration goals. The assessment of the current conditions was elaborated particularly to determine those factors, which could limit restoration. These assessments cover the land use pattern, furthermore the analysis of vegetation and habitat patches. As a result of the historical analysis, it has been found that the stream side habitat patches have decreased significantly despite the constant space available. This change was not caused by the increased area of the settlement, but rather by the higher dominancy of arable forms of land use. The greatest share of wet and mesic meadows and agricultural habitats in the study areas, covering 57.5% of the total area, indicates significant anthropogenic effects. Consequently it can be stated that the reference conditions are not the only determining factors of the restoration possibilities. Restoration style and intensity have been defined on basis of all assessed factors.

Forestry and wood industry have formed a foundation for Finland's national economy, yet inevitably at the expense of aquatic environments. From 1940s to 1970s, to provide energy resources for the industry sector, majority of large rivers were dammed for hydropower, blocking off their longitudinal connectivity. Concurrently, majority of the stream channels were dredged to facilitate timber transportation from headwaters to downriver factories. While most large rivers remain blocked, the timber floating ceased in the 1980s, and legislation imposing restoration as well as intensive restoration programs have been established ever since. Habitat restoration has mostly been motivated by the enhancement of recreational fisheries through the provision of better living conditions for salmonids. The measures have included construction of in-stream structures, such as weirs, flow deflectors, boulder dams and gravel beds, and recently also installation of large wood. Based on before-after-restoration measurements of physical variables and habitat-hydraulic modeling, the measures have been effective in enhancing complexity of stream beds and hydraulic conditions, thus potentially increasing the availability of suitable habitat for juvenile brown trout. The increase in habitat heterogeneity has been persistent over time, and has also shown positive signs in functional processes of stream ecosystem. Nevertheless, overall substrate variability in restored streams has remained lower than in natural streams, especially with a shortage of gravel beds for brown trout spawning. Sound ecological monitoring of restoration projects has been limited in Finland. A few long term before-after-restoration monitoring of brown trout densities, together with a meta-analytical synthesis of all good-quality monitoring data, have indicated an overall positive effect on brown trout parr densities. Yet, the absolute juvenile brown trout density in post-management streams has mainly remained lower than in natural reference streams. In addition, brown trout responses have varied strongly between restored streams. The strong context-dependency in restoration outcomes is explained mainly by catchment scale (e.g. river basin size, dominant geology) and local (potential interspecific competition, fisheries management) factors. Among the local fisheries management measures, loosely restricted fishing has diluted the positive effects of restoration, and stocking by eggs and parr have either been ineffective or affected negatively brown trout's response to restoration. Stream-specific differences have also been observed in the delivery of ecosystem services, mainly reflecting stakeholder perceptions of landscape values and fish provisioning. Yet, stream restoration in its present form has a strong public acceptance in Finland, mainly because it is considered beneficial for recreationally important fish, ecotourism, and the well-being of local people. ; peerReviewed

Agriculture is widespread across the EU and has caused considerable impacts on freshwater ecosystems. To revert the degradation caused to streams and rivers, research and restoration efforts have been developed to recover ecosystem functions and services, with the European Water Framework Directive (WFD) playing a significant role in strengthening the progress. Analysing recent peer-reviewed European literature (2009–2016), this review explores 1) the conflicts and difficulties faced when restoring agriculturally impacted streams, 2) the aspects relevant to effectively reconcile agricultural land uses and healthy riverine ecosystems and 3) the effects and potential shortcomings of the first WFD management cycle. Our analysis reveals significant progress in restoration efforts, but it also demonstrates an urgent need for a higher number and detail of restoration projects reported in the peer-reviewed literature. The first WFD cycle ended in 2015 without reaching the goal of good ecological status in many European water-bodies. Addressing limitations reported in recent papers, including difficulties in stakeholder integration and importance of small headwater streams, is crucial. Analysing recent developments on stakeholder engagement through structured participatory processes will likely reduce perception discrepancies and increase stakeholder interest during the next WFD planning cycle. Despite an overall dominance of nutrient-related research, studies are spreading across many important topics (e.g. stakeholder management, land use conflicts, climate change effects), which may play an important role in guiding future policy. Our recommendations are important for the second WFD cycle because they 1) help secure the development and dissemination of science-based restoration strategies and 2) provide guidance for future research needs

Green and blue infrastructure in cities -- Climate change : mitigation and adaptation strategies -- Environmental and ecological imbalances in dense urban areas -- Water in urban areas : ecological and environmental issues and strategies -- Ecosystem services in urban areas : social, environmental, and economic benefits -- Green and blue infrastructure : vegetated systems -- Green and blue infrastructure : unvegetated systems -- Urban river restoration -- Strategies and techniques : case studies -- Green and blue infrastructure top-down policies -- Bottom-up initiatives for green and blue infrastructure -- Selection of management practices and guidelines -- Opportunities and policies : case studies

International audience ; Urban rivers are highly disturbed ecosystems. Indeed, urban rivers have been dammed and sometimes buried. The aim was to reduce the risk of flooding and solve health problems due to water pollution. In the mid-20th century, many cities have turned banks into parking. Cities and rivers were therefore separated due to urban development. Since the 1960s and 1970s, the water policy was to build or upgrade the wastewater treatment plants and water treatment plants. In Europe and North America, however, the legislation has evolved over the last fifteen years for increased and overall protection of aquatic ecosystems. The hydromorphological river restoration is now a priority of the new water policy in Europe. This is why cities are experimenting with today's renaturation projects of urban rivers: both territorial marketing and sustainable development. This article defines the concept of renaturation. The paper also presents two case studies: Quebec in Canada and Lyon in France to evaluate the advantages and limitations of this concept.

International audience ; Urban rivers are highly disturbed ecosystems. Indeed, urban rivers have been dammed and sometimes buried. The aim was to reduce the risk of flooding and solve health problems due to water pollution. In the mid-20th century, many cities have turned banks into parking. Cities and rivers were therefore separated due to urban development. Since the 1960s and 1970s, the water policy was to build or upgrade the wastewater treatment plants and water treatment plants. In Europe and North America, however, the legislation has evolved over the last fifteen years for increased and overall protection of aquatic ecosystems. The hydromorphological river restoration is now a priority of the new water policy in Europe. This is why cities are experimenting with today's renaturation projects of urban rivers: both territorial marketing and sustainable development. This article defines the concept of renaturation. The paper also presents two case studies: Quebec in Canada and Lyon in France to evaluate the advantages and limitations of this concept.

International audience ; Urban rivers are highly disturbed ecosystems. Indeed, urban rivers have been dammed and sometimes buried. The aim was to reduce the risk of flooding and solve health problems due to water pollution. In the mid-20th century, many cities have turned banks into parking. Cities and rivers were therefore separated due to urban development. Since the 1960s and 1970s, the water policy was to build or upgrade the wastewater treatment plants and water treatment plants. In Europe and North America, however, the legislation has evolved over the last fifteen years for increased and overall protection of aquatic ecosystems. The hydromorphological river restoration is now a priority of the new water policy in Europe. This is why cities are experimenting with today's renaturation projects of urban rivers: both territorial marketing and sustainable development. This article defines the concept of renaturation. The paper also presents two case studies: Quebec in Canada and Lyon in France to evaluate the advantages and limitations of this concept.

International audience ; Urban rivers are highly disturbed ecosystems. Indeed, urban rivers have been dammed and sometimes buried. The aim was to reduce the risk of flooding and solve health problems due to water pollution. In the mid-20th century, many cities have turned banks into parking. Cities and rivers were therefore separated due to urban development. Since the 1960s and 1970s, the water policy was to build or upgrade the wastewater treatment plants and water treatment plants. In Europe and North America, however, the legislation has evolved over the last fifteen years for increased and overall protection of aquatic ecosystems. The hydromorphological river restoration is now a priority of the new water policy in Europe. This is why cities are experimenting with today's renaturation projects of urban rivers: both territorial marketing and sustainable development. This article defines the concept of renaturation. The paper also presents two case studies: Quebec in Canada and Lyon in France to evaluate the advantages and limitations of this concept.

International audience ; Urban rivers are highly disturbed ecosystems. Indeed, urban rivers have been dammed and sometimes buried. The aim was to reduce the risk of flooding and solve health problems due to water pollution. In the mid-20th century, many cities have turned banks into parking. Cities and rivers were therefore separated due to urban development. Since the 1960s and 1970s, the water policy was to build or upgrade the wastewater treatment plants and water treatment plants. In Europe and North America, however, the legislation has evolved over the last fifteen years for increased and overall protection of aquatic ecosystems. The hydromorphological river restoration is now a priority of the new water policy in Europe. This is why cities are experimenting with today's renaturation projects of urban rivers: both territorial marketing and sustainable development. This article defines the concept of renaturation. The paper also presents two case studies: Quebec in Canada and Lyon in France to evaluate the advantages and limitations of this concept.