A 2018 study by Borst et al.. tested the general hypothesis that foundation species – spatially dominant habitat-structuring organisms Angelini C, Altieri AH, Silliman BR, Bertness MD. Interactions among foundation species and their consequences for community organization, biodiversity, and conservation. Bioscience. 2011;61(10):782–9.Dayton PK. Toward an understanding of community resilience and the potential effects of enrichments to the benthos at McMurdo Sound, Antarctica. In: Parker B, editor. Proceedings of the Colloquium on Conservation Problems in Antarctica. Lawrence, Kansas: Allen Press; 1972. – modify food webs by enhancing their size as indicated by species number, and their complexity as indicated by link density, via facilitation of species, regardless of ecosystem type (see diagram). Additionally, they tested that any change in food web properties caused by foundation species occurs via random facilitation of species throughout the entire food web or via targeted facilitation of specific species that belong to certain trophic levels or functional groups. It was found that species at the base of the food web are less strongly, and carnivores are more strongly facilitated in foundation species' food webs than predicted based on random facilitation, resulting in a higher mean trophic level and a longer average chain length. This indicates foundation species strongly enhance food web complexity through non-trophic facilitation of species across the entire trophic network.
