Ecological networks of an Antarctic ecosystem: a full description of non-trophic interactions

Abstract

Interactions between organisms are diverse and attend to multiple biological demands; hence, understanding ecological communities requires considering different types of species interactions beyond predation. In this work, we assembled the non-trophic networks of a marine Antarctic ecosystem for the first time. We report mutualistic (+ / +), competitive (− / −), commensalistic (+ /0) and amensalistic (− /0) interactions between species of the Potter Cove marine community (South Shetland Is., Antarctica). Based on a network approach, we present a full description of each type of interaction and analyze its distribution according to different species-level properties. Also, we constructed a multiple interactions network including trophic and non-trophic interactions and studied network-level properties. We found more than double non-trophic interactions than trophic mostly corresponding to competitive interactions that mainly involve mid-trophic level species. Low-trophic level species were mainly involved in mutualistic and amensalistic interactions. We observed that single-type interaction networks display differences in their topology. Finally, we highlight that including a description of species interactions in ecological network analyses provides a better understanding of ecosystems which it is crucial to comprehend and predict ecosystems responses to environmental changes.