Restoration of a Danish headwater stream: short‐term changes in plant species abundance and composition

Abstract

1. This paper describes the short-term effects (2 years) of stream restoration on vascular plant communities in a 1.4 km upper reach of the River Gudenå, Denmark. The effects of restoration were assessed in terms of the abundance and composition of plant species in the stream, on the banks and in the stream valley. 2. Total species richness was similar before and after restoration, and comprised approximately 150 species representing 12% of the entire Danish vascular plant flora. 3. In the stream, total plant cover had not recovered to pre-restoration levels 2 years after restoration. Cover by submerged, amphibious and terrestrial species growing submerged decreased, as did the number of amphibious and terrestrial species growing submerged. 4. On the banks, total plant cover almost attained pre-restoration levels the second year after restoration. The plant communities changed from dominance by non-riparian species to more diverse communities with a greater number and increased cover of riparian gramineous species requiring a higher soil moisture content. 5. In the valley, the plant communities only changed slightly after restoration, although growth of riparian species was enhanced on the southern side of the stream. Copyright © 2000 John Wiley & Sons, Ltd.