Sammanfattning

Restoration of channelized streams by returning coarse sediment from stream edges to the wetted channel has become a common practice in Sweden. Yet, restoration activities do not always result in the return of desired biota. This study evaluated a restoration project in the Vindel River in northern Sweden in which practitioners further increased channel complexity of previously restored stream reaches by placing very large boulders (>1m), trees (>8m), and salmonid spawning gravel from adjacent upland areas into the channels. One reach restored with basic methods and another with enhanced methods were selected in each of ten different tributaries to the main channel. Geomorphic and hydraulic complexity was enhanced but the chemical composition of riparian soils and the communities of riparian plants and fish did not exhibit any clear responses to the enhanced restoration measures during the first 5years compared to reaches restored with basic restoration methods. The variation in the collected data was among streams instead of between types of restored reaches. We conclude that restoration is a disturbance in itself, that immigration potential varies across landscapes, and that biotic recovery processes in boreal river systems are slow. We suggest that enhanced restoration has to apply a catchment-scale approach accounting for connectivity and availability of source populations, and that low-intensity monitoring has to be performed over several decades to evaluate restoration outcomes.

Nyckelord

fish; geomorphic complexity; hydraulics; ice; landscape scale; restoration; riparian chemistry; riparian plants; Sweden

Publicerad i

Ecosystems
2017, Volym: 20, nummer: 1, sidor: 144-162

SLU författare

• Palm, Daniel

  • Institutionen för vilt, fisk och miljö, Sveriges lantbruksuniversitet
    

• Lundqvist, Hans

  • Institutionen för vilt, fisk och miljö, Sveriges lantbruksuniversitet
    

Globala målen

SDG6 Säkerställa tillgången till och en hållbar förvaltning av vatten och sanitet för alla
SDG15 Skydda, återställa och främja ett hållbart nyttjande av landbaserade ekosystem, hållbart bruka skogar, bekämpa ökenspridning, hejda och vrida tillbaka markförstöringen samt hejda förlusten av biologisk mångfald


UKÄ forskningsämne

Ekologi
Fisk- och akvakulturforskning
Oceanografi, hydrologi, vattenresurser


Publikationens identifierare

DOI: https://doi.org/10.1007/s10021-016-0020-0

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/77380