Responses of riparian plants to habitat changes following restoration of channelized streams

• Published in: Ecohydrology
• Main Authors: Kuglerová, Lenka, Botková, Kamila, Jansson, Roland
• Other Authors: Svenska Forskningsrådet Formas
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2016
• Subjects: Earth-Surface Processes; Ecology; Aquatic Science; Ecology, Evolution, Behavior and Systematics; Northern Sweden
• Online Access: http://dx.doi.org/10.1002/eco.1798; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Feco.1798; https://onlinelibrary.wiley.com/doi/pdf/10.1002/eco.1798; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/eco.1798

Abstract The ecological effects of stream restoration were evaluated by comparing riparian vegetation, flooding, and habitat properties between channelized and two types of restored streams in northern Sweden. Channelized streams were straightened and cleared of in‐stream boulders and wood >50 years ago to facilitate timber floating. Basic restoration (performed 8–10 years ago) returned cleared material back to the channels, and enhanced restoration (3 years ago) added large structural elements (boulders and downed trees) to previously basic‐restored streams. Riparian inundation duration increased only after enhanced restoration. Similarly, enhanced‐restored reaches had the highest amount of substrate available for plant establishment compared to channelized and basic‐restored streams. In contrast, soil biochemical properties (pH and C:N ratio) did not improve following either restoration effort. Riparian plant cover was higher at both restored types than channelized reaches. Plant species richness was higher at plot‐scale level (0.25 m 2 ) at both restored types in the most species‐rich elevation levels compared to channelized reaches, whereas at the reach‐scale (>700 m 2 of riparian area), species richness did not differ among stream types. Similarly, species composition segregated between channelized and restored reaches only at the plot scale. We found no significant differences in riparian vegetation between the two restored types. The lack of positive responses of vegetation to enhanced restoration and to variables that changed immediately after restoration (inundation, habitat area) implies that responses were either slower than expected or the changes in hydrology and substrate availability were not as important for riparian flora as believed.