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AUTHOR
Pauliina Louhi
showing 5 related works from this author
Synthesis of habitat restoration impacts on young-of-the-year salmonids in boreal rivers
2019
River restoration offers the potential to enhance biological integrity, often measured as fish population changes. We used a meta-analytical approach to synthesize density responses to in-stream habitat restoration by young-of-the year (YOY) brown trout and Atlantic salmon in 28 rivers (overall 32 restoration projects) in Finland. We also examined which local and watershed-scale factors most influenced restoration success. Finally, we conducted an expert survey to obtain an independent estimate of a sufficient density enhancement for restoration to be considered successful. Despite strong context-dependency, habitat restoration had an overall positive effect on YOY salmonid density. When co…
Stream salmonids as opportunistic foragers: the importance of terrestrial invertebrates along a stream-size gradient
2011
Terrestrial invertebrates have been reported to be positively selected by stream salmonids. We assessed the impor- tance of terrestrial and aquatic invertebrates to salmonid diets in 25 streams in Finland, with the hypothesis that terrestrial prey would be important in only the smallest forest streams. Several measures of prey availability were used, including pro- portional abundance in benthic or drift samples, compared with a trait-based approach, to predict diet composition. Across all 25 streams in autumn, blackfly and caddis larvae were the most important prey items. Terrestrial invertebrates were of moderate importance in all streams, including the smallest. Pure availability predict…
Life in the ice lane: the winter ecology of stream salmonids
2007
Despite the common view that conditions in winter strongly influence survival and population size of fish, the ecology of salmonids has not been as extensively studied in winter as in other seasons. In this paper, we review the latest studies on salmonid winter survival, habitat use, movement and biotic interactions as they relate to the prevailing physical and habitat conditions in rivers and streams. The majority of research conducted on the winter ecology of salmonids has been carried out in small rivers and streams, where temperatures are above zero and where there is no ice. Investigations in large rivers, regulated and dredged rivers, and under conditions of different ice formations a…
FRESHABIT: The LIFE integrated project for restoration of wetland ecosystems at the catchment level
2018
Freshwaters provide multiple natural and cultural ecosystem services, which form the basis of Finnish water heritage. In most cases, the deterioration of freshwater ecosystems is due to a range of interacting background factors at many scales, and reversing the trend requires comprehensive restoration measures in catchment areas and water systems as well. Following this, to preserve our valuable water heritage, the co-operation across human-set boundaries is required. Funding for restoration projects conventionally comes from one or few sources and is often targeted to a given habitat or species. However, enhancing the ecological status of many inter-connected habitats or species usually re…
In-stream restoration in forestry impacted catchments: benefits to stream habitats, brown trout populations and society
2018
Forestry and wood industry have formed a foundation for Finland’s national economy, yet inevitably at the expense of aquatic environments. From 1940s to 1970s, to provide energy resources for the industry sector, majority of large rivers were dammed for hydropower, blocking off their longitudinal connectivity. Concurrently, majority of the stream channels were dredged to facilitate timber transportation from headwaters to downriver factories. While most large rivers remain blocked, the timber floating ceased in the 1980s, and legislation imposing restoration as well as intensive restoration programs have been established ever since. Habitat restoration has mostly been motivated by the enhan…