"Mangfold, spredning og opphav til karplanter i og langs en blågrønn infrastruktur-bekk på campus til Norges Miljø- og Biovitenskapelige Universitet"

Sammendrag

Abstract Anthropogenic climate change and biodiversity loss are two of the major challenges of the 21st century. Blue-green infrastructure (BGI) offers potential solutions to address the impacts of both, including handling excessive flood water and providing habitat and dispersion corridors for a number of species. Plants are a vital part of any BGI project, aiding in the stabilizing of stream banks, absorbing excess water and providing habitat for wildlife. The aim of my study was to investigate the diversity of vascular plants in and and alongside a BGI-stream called the Campus Stream, located on the campus of the Norwegian University of Life Science, at Ås, in South-Eastern Norway. The study was conducted by doing vegetation surveys in 0.5 x 0.5 plots on transects placed across the stream and riparian vegetation. All plants within each plot were identified, preferably to species level, and the cover within the plot was estimated. The origin of each species, e.i. if they were planted or spontaneously occurring, was also determined as far as possible using maps over the initial plantings conducted by the contractors after the construction of the stream, as well as information from representatives of the park management. In total, 134 taxa were identified during the field work, the most common being native wetland species, as well as a number of generalists. The streambed, not initially planted, generally exhibited relatively high degrees of vegetation cover, indicating spread from the banks and surrounding areas. The streambed was dominated by wetland specialists and aquatic plants, indicating considerable ability to spread among these species. Most taxa identified were classified as spontaneous, but the taxa that had been planted were considerably more dominant in terms of cover. Significant differences in species diversity were observed among the different areas of the stream, likely driven by variation in construction, maintenance and initial plantings. Further research is needed to identify the variables contributing to the differences in diversity. The study shows that BGI-structures can provide habitat for numerous species of vascular plants, including red-listed species, which in turn can provide several ecosystem services. The information might be useful for park management, landscape designers and others that create or manage blue-green infrastructure.