Restoration effects on germination and survival of plants in the riparian zone: a phytometer study
2015 (English)In: Plant Ecology, ISSN 1385-0237, E-ISSN 1573-5052, Vol. 216, no 3, 465-477 p.Article in journal (Refereed) Published
Many streams that were channelized to facilitate timber floating in northern Sweden, have in recent years been restored by returning coarse sediment (cobbles and boulders) to the channel and reconnecting riparian with instream habitats. We asked if such restoration measures affect germination and survival of plants in the riparian zone, and if such potential effects depend on location in the catchment. We used a paired site approach, comparing the performance of Helianthus annuus (sunflower) phytometers (seeds and seedlings) in the riparian zone in channelized versus restored river reaches along climate and stream size gradients in the Vindel River catchment in northern Sweden. Phytometer survival, substrate availability, and soil nutrient content in large streams were enhanced by restoration, but overall, phytometer performance was negatively related to the length of the growing season, i.e. phytometers grew best at high altitudes and short growing seasons. This result may have been caused by less competition from the shorter and sparser neighbouring vegetation at these sites or to more frequent flooding events, enhancing retention of organic matter. Soil nutrient levels were lowest close to the coast and in large streams, probably due to deposition of mineral sediment. The higher availability of riparian habitat at restored than at channelized sites suggests that plant species richness and abundance may potentially increase after restoration. Seedling transplantation seems to be a preferable revegetation measure, because phytometer seedlings established better than seeds and survival was significantly higher at restored sites. The good plant performance at sites with short growing seasons and high altitudes suggests that, with limited resources, restoration measures should first be located to such sites.
Place, publisher, year, edition, pages
2015. Vol. 216, no 3, 465-477 p.
Habitat availability, Helianthus annuus, Plant performance, Relative growth rate, Soil, Sunflower, rvival, Sweden
IdentifiersURN: urn:nbn:se:umu:diva-101385DOI: 10.1007/s11258-015-0450-3ISI: 000349975000010OAI: oai:DiVA.org:umu-101385DiVA: diva2:840221
Originally published in manuscript form with title "Restoration effects on germination and establishment of plants in the riparian zone: a phytometer study"2015-07-072015-03-302016-05-18Bibliographically approved