Vegetation i förändring - en jämförelse mellan två vattendrag

Sammanfattning: Restoring and meandering straightened streams is an important part of the Swedish environmental objective “Live lakes and water courses”. Restoration improves the living conditions for plants and animals that reside in or near the stream, and increases the uptake of excess nutrients leaking from nearby farmland. In this study, I have examined two restored streams; Glomsbäcken and Trollebergssträckan in Lund, Sweden. I wanted to investigate whether the vegetation in the two locations had improved since the restorations, and if I could make any conclusions regarding the future of the streams. By performing an inventory of the vegetation in and alongside the two streams, and comparing the results to prior observations and reports, I discovered that both streams host many species indicating high nutrient levels. In the case of Trollebergssträckan, this was expected since it is surrounded by farmland and therefore is the recipient of highly nutritious groundwater. Glomsbäcken is in itself somewhat nutrient rich due to the naturally eutrophic water coming from Glomsjön - the outlet for Glomsbäcken. The species I found that indicate nutrient rich waters and soils are tall and fast growing, such as great manna grass Glyceria maxima, great willowherb Epilobium hirsutum and common reed Phragmites australis. These need to be monitored to keep them from growing to great stands and cause overgrowth. Continued management on both sites is essential for the restorations to be successful and for the two streams not to return to their pre-restoration states.