Epsilon Archive for Student Projects

Abstract

The loss of biodiversity and natural ecosystems and the freshwater crisis are among the most critical global challenges of our time. Hydropower dams cause fragmentation of river systems and have major impacts on aquatic and terrestrial vegetation and fauna. During dam construction, rivers were dredged and sand and sediment were often deposited along the banks, creating new or modified riparian zones. These modified sites exist in large numbers to date and there is a lack of research to understand the dynamics and possible restoration potential of these habitats. The aim of this study is to assess the faunistic biodiversity of riparian zones affected by dredging. For this, several biodiversity measurements were carried out using camera trapping, bioacoustics, insect trapping and eDNA soil sampling. In addition, environmental factors measured using drone surveys and satellite imagery were used to identify variation between sites and their impact on biodiversity, and to provide information on the ecological restoration potential of modified sites. The studied highly modified riparian zone close to the Gallejaur hydropower plant showed the lowest overall diversity, while the moderately modified riparian zone close to the Rusfors power plant showed a diverse species community, indicating the ecological potential of the modified site and highlights the importance of surrounding areas. The natural site along the free-flowing Vindel River (Vormfors) showed the highest overall faunistic diversity. The environmental factors suggest that increased vertical heterogeneity, greater variation in annual flow, higher NDVI values, larger (mean) vegetation and less steep slopes (within the first 10 metres from the river) can be used to distinguish natural and modified riparian areas and are likely to be associated with differences in biodiversity.