Responses of riparian plant communities and water quality after 8 years of passive ecological restoration using a BACI design
Résumé
This study investigated the consequences of passive ecological restoration on a riparian habitat and on water quality. The restoration plan consists of excluding livestock by constructing fences along an entire stream 1 m from the stream bed, with the assumption that recovering riparian habitat will restore their ecological processes (e.g., filtration, soil stabilization). We measured responses of riparian plant communities and physico-chemical water quality. We presented data from an 8-year before-after control-impact design across a reference stream and a restored stream in a rural landscape in Normandy, France. Restoration appeared to modify plant communities. After 8 years of restoration, the restored stream had a complex riparian bank, similar to that of the reference stream, with an increase in the number of trees, a decrease in bare soil, and an increase in habitat heterogeneity. Despite this modification, water quality did not improve. The same low water quality in the reference stream demonstrated the need for a watershed-scale approach and for actions to improve agricultural practices before implementing restoration practices at a smaller scale. Nonetheless, the lack of improved water quality does not necessarily mean that the restoration failed. Other functions and services can be provided by excluding livestock.
Mots clés
BACI design
Headwater
Bundles of ecosystem services
Passive
ecological restoration
Riparian plant communities
Watershed
Water
quality
western united-states
integrated catchment management
in-stream
restoration
salmon salmo-salar
river restoration
headwater streams
macroinvertebrate assemblages
wetland restoration
european rivers
habitat
Marine & Freshwater Biology