Aquatic-terrestrial food web linkages along rivers

摘要

Rivers are open ecosystems that are characterized by intensive flows of matter and organisms between land and water. Aquatic resource fluxes to terrestrial systems, such as emerging aquatic insects, can subsidise a diversity of terrestrial consumers.The aim of the present paper is to synthesize recent research on aquatic-terrestrial subsidies with particular emphasis on biological complexity. We studied taxon-specific aquatic-terrestrial food web linkages for a riparian arthropod assemblage in the braided Tagliamento River (north east Italy) using a combined approach of field experiments and stable isotope analysis. The riparian arthropod assemblage relied substantially on riverine resource inputs (i.e. aquatic insect emergence and surface drift).However, the contributions of aquatic prey to riparian arthropod diets differed considerably among taxa and over seasons. The results suggest that the diversity of life history traits of riparian consumers may enhance the use of riverine subsidies by riparian food webs. Finally, we discuss how the role of aquatic-terrestrial subsidies is expected to change as landscape characteristics change along a river corridor.