Ecological principles and stream restoration (original) (raw)

Over forty years of lowland stream restoration: Lessons learned?

Journal of Environmental Management

Stream restoration efforts have increased, but the success rate is still rather low. The underlying reasons for these unsuccessful restoration efforts remain inconclusive and need urgent clarification. Therefore, the aim of the present study was to evaluate over 40 years of stream restoration to fuel future perspectives. To this purpose we evaluated the influence of policy goals on stream restoration efforts, biophysical restoration objectives, restoration measures applied including the scale of application and monitoring efforts. Information was obtained from five stream restoration surveys that were held among the regional water authorities in the Netherlands over the last 40 years and from an analysis of the international scientific publications on stream restoration spanning the same time period. Our study showed that there was a considerable increase in stream restoration efforts, especially motivated by environmental legislation. However, proper monitoring of the effectiveness of the measures was often lacking. Furthermore, a mismatch between restoration goals and restoration measures was observed. Measures are still mainly focused on hydromorphological techniques, while biological goals remain underexposed and therefore need to be better targeted. Moreover, restoration practices occur mainly on small scales, despite the widely recognized relevance of tackling multiple stressors acting over large scales for stream ecosystem recovery. In order to increase the success rate of restoration projects, it is recommended to improve the design of the accompanying monitoring programmes, allowing to evaluate, over longer time periods, if the measures taken led to the desired results. Secondly, we advise to diagnose the dominant stressors and plan restoration measures at the appropriate scale of these stressors, generally the catchment scale.

The role of stream restoration in enhancing ecosystem services

Hydrobiologia

Striving for an integrated semi-natural stream-floodplain system as restoration target would optimally serve biodiversity and the provisioning of ecosystem services. This pursuit is currently limited by multiple pressures and constraints that come with, amongst others, a high human population density and intensive land-use. To be able to weigh the ecological and societal needs in lowland-stream watersheds, we analysed the developments in lowland-stream restoration in relation to the actual and potential state of ecosystems services these systems provide. To reach an ecological-societal balance in stream restoration, we pose five steps: (i) Choose a clear and realistic restoration target, (ii) Map and quantify environmental stressors at local to watershed scale, (iii) Map and quantify biological indicators at local to regional scale, (iv) List potential restoration measures to remove or mitigate stressors, and (v) Build scenarios, composed of combinations of measures fitting the soci...

And Challenges in River Restoration – the

2016

www.hydrol-earth-syst-sci.net/18/2449/2014/ doi:10.5194/hess-18-2449-2014 © Author(s) 2014. CC Attribution 3.0 License. Morphological, hydrological, biogeochemical and ecological changes

Report on the restoration success of lowland streams following remeandering projects

2009

Project co-funded by the European Commission within the Sixth Framework Programme (2002-2006) Dissemination Level (tick appropriate box) PU Public PP Restricted to other programme participants (including the Commission Services) RE Restricted to a group specified by the consortium (including the Commission CO Confidential, only for members of the consortium (including the Commission Services)

A General Protocol for Restoration of Regulated Rivers

Regulated Rivers: Research & Management, 1996

Large catchment basins may be viewed as ecosystems in which natural and cultural attributes interact. Contemporary river ecology emphasizes the four-dimensional nature of the river continuum and the propensity for riverine biodiversity and bioproduction to be largely controlled by habitat maintenance processes, such as cut and fill alluviation mediated by catchment water yield. Stream regulation reduces annual flow amplitude, increases baseflow variation and changes temperature, mass transport and other important biophysical patterns and attributes. As a result, ecological connectivity between upstream and downstream reaches and between channels, ground waters and floodplains may be severed. Native biodiversity and bioproduction usually are reduced or changed and non-native biota proliferate.

Reconciling theory and practise: The role of stream ecology

River Research and Applications, 2010

Stream ecology has played an important role in advancing general ecological theory. As an integrating element in complex landscapes, our understanding of ecological indicators, the movement of energy and materials across ecosystems and the pervasive importance of disturbance and dynamics has been critically informed by our study of streams. Faced with increases in the demands for water and changes in the patterns of rainfall and evaporation due to climate change, the need to apply ecological theory to management practice has become all the more immediate. This will involve not only restoration, but reconstruction and engineering of whole ecosystems. We review the key areas of theory that have been informed by stream ecology, and lay down a challenge to the next generation of stream ecologists, to drive ahead theory while applying it to real challenges.

A tale of two streams: restoration strategies compared

1996

Many stream ecosystems are severely limited by damaged physical habitat. Channelization and associated accelerated erosion is a primary cause of damages in agricultural watersheds. Cost-effective strategies are needed to address erosion problems and restore stream corridor habitats. Detailed studies of restoration outcomes are rare. Herein we present a case study of two small streams (watershed size = 12 and 14 km 2) damaged by channel straightening and incision. One stream was stabilized using a low drop grade control structure and dormant willow post planting, while the other was treated with a stone weir, stone toe bank protection, and willow sprout planting. Effects of restoration were monitored by collecting physical and biological data for one to two years before restoration and two to three years afterward. Following construction, channel planforms were stable, but up to 1 m of deposition and erosion occurred along the thalweg profile. Willow planting was not successful, so canopy, bank vegetation and woody debris density were unchanged. Pool habitat area increased from less than 5% to more than 30%. Fish species richness was unchanged, but species composition shifted away from cyprinids that occur in shallow, sandy runs toward pool-dwelling types (catostomids and centrarchids). Response to restoration was more modest than for two nearby restoration projects. Potential causes include less ambitious restoration design, greater initial degradation, and isolation from less-degraded sites which could serve as sources of colonists.