Abstract
Boreal stream ecosystems have large intrinsic values but our understanding about their structure and function is still weak which holds back the development of useful management strategies. This deficit is unfortunate because boreal forests are strongly affected by forestry and predicted to experience relatively strong climate change effects with likely negative consequences for stream communities and their ability to deliver ecosystem goods and services. Current knowledge seems to suffer especially from being dated and from misconceptions, e.g. that streams are fuelled by detritus generally. The functional feeding group concept (FFG) is unclear, community assembly is believed to be deterministic and possible to describe by standard investigations. This project will test the hypotheses that 1) light radiation in boreal forests makes streams autotrophic, except in winter, 2) gut analyses and stable isotope analysis better link food and consumers than FFG, 3) only when disturbed, communities shift from higher species richness and beta diversity into deterministic, homogenous ones. In addition, 4) components of biodiversity such as dominance and biomass as well as the identities of often neglected but putatively important taxa improve ecological understanding. The work will be carried out in northern Sweden in a carefully selected set of 12 streams (6 controls, 6 forestry-impacted). The study is expected to generate useful results for stream management and conservation.
Sweden