Substrate size modifies stream grazer-biofilm interactions in the presence of invertivorous fish.

ABSTRACT: When herbivore abundance is controlled by predators there may be an indirect positive effect on primary producers due to reduced grazing pressure, but the potential of predation refuges to modify such trophic cascades has rarely been studied. By experimentally manipulating substrate particle size and fish predation regime, we assessed the outcome of invertebrate grazer-biofilm interactions in streams. Locations at the center of larger substrate particles were predicted to pose a higher predation risk, and therefore be subjected to a lower grazing pressure. In our 52-day experiment in a New Zealand stream, small-sized substrates (terracotta tiles) remained virtually free of periphyton across their entire upper surface, whereas a thick periphyton mat was formed across large tiles with only e

SUBMITTER: Albarino RJ 

PROVIDER: S-EPMC10078335 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature