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Refuge increases food chain length: modeled impacts of littoral structure in lake food webs
Author(s) -
Ziegler Jacob P.,
GregoryEaves Irene,
Solomon Christopher T.
Publication year - 2017
Publication title -
oikos
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.672
H-Index - 179
eISSN - 1600-0706
pISSN - 0030-1299
DOI - 10.1111/oik.03517
Subject(s) - food chain , trophic level , ecosystem , food web , littoral zone , ecology , environmental science , biomass (ecology) , apex predator , lake ecosystem , biology
Food chain length (FCL) represents a fundamental metric within ecology because it has implications for ecosystem function and responses to environmental change. Omnivory between linked food chains situated within large ecosystems can increase FCL, whereas overlap of food chains within small or spatially compressed ecosystems is generally thought to decrease FCL. Yet FCL varies widely in small ecosystems and the mechanisms underlying determinants of FCL in these systems is unclear. In small shallow lakes, littoral structure is a predictor of FCL but it is unclear whether this is due to productivity or refuge mechanisms. Here we provide evidence, using consumer resource food web modules parameterized with empirical data, that refuge in spatially compressed ecosystems has the ability on its own to increase the trophic position of top predators by increasing the biomass of top and intermediate predators across a range of common food web module structures. Our results suggest that refuge is an important driver of FCL in small ecosystems, which has implications for determining responses of these systems to environmental change.