Premium
Bending the rules: exploitation of allochthonous resources by a top‐predator modifies size‐abundance scaling in stream food webs
Author(s) -
Perkins Daniel M.,
Durance Isabelle,
Edwards Francois K.,
Grey Jonathan,
Hildrew Alan G.,
Jackson Michelle,
Jones J. Iwan,
Lauridsen Rasmus B.,
LayerDobra Katrin,
Thompson Murray S. A.,
Woodward Guy
Publication year - 2018
Publication title -
ecology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.852
H-Index - 265
eISSN - 1461-0248
pISSN - 1461-023X
DOI - 10.1111/ele.13147
Subject(s) - allometry , ecosystem , ecology , streams , apex predator , predation , dominance (genetics) , scaling , abundance (ecology) , predator , aquatic insect , biology , food web , invertebrate , habitat , mathematics , computer network , biochemistry , geometry , computer science , gene
Body mass–abundance ( M‐N ) allometries provide a key measure of community structure, and deviations from scaling predictions could reveal how cross‐ecosystem subsidies alter food webs. For 31 streams across the UK, we tested the hypothesis that linear log‐log M‐N scaling is shallower than that predicted by allometric scaling theory when top predators have access to allochthonous prey. These streams all contained a common and widespread top predator (brown trout) that regularly feeds on terrestrial prey and, as hypothesised, deviations from predicted scaling increased with its dominance of the fish assemblage. Our study identifies a key beneficiary of cross‐ecosystem subsidies at the top of stream food webs and elucidates how these inputs can reshape the size‐structure of these ‘open’ systems.