Abstract
Food webs constitute an important biological concept, depicting ecological communities as detailed networks of trophic interactions. Parasites have rarely been included in food-web studies, despite their omnipresence and the fact that parasitism represent s the most common consumer strategy among organisms. With a growing awareness of the potential importance of parasites in trophic networks, there has recently been a comprehensive call for their inclusion in food-web analyses. The proposed project address es key issues related to the topology and functioning of food webs with special emphasis on the role of parasites, using subarctic lakes as a model system. Two contrasting but complimentary approaches are employed; the first being related to the establish ment and analysis of the detailed structure of a whole-lake food web including parasites in a subarctic lake ecosystem, and the latter to the investigations of a key sub-web interaction module (fish predators, their prey and their trophically transmitted parasites) in time (long-term within-lake variations) and space (between-lake variations). The adopted framework facilitates in-depth exploration of the importance of parasites in food webs, including analyses of compartmentalisation and main energy pathw ays, assessment of the impacts of fish species additions and their potential hitchhiking parasites on food-web structure and dynamics, and an evaluation of the role of fish species composition for parasite transmission and the functioning of the trophic n etwork. The addressed topics represent fundamental objectives in ecology and conservation biology that presently are receiving increasing attention from the scientific community. The project will also provide important insight to the functioning and persi stence of vulnerable arctic ecosystems.
Norway