title: From wing to wing: the persistence of long ecological interaction chains in less-disturbed ecosystems.
abstract: Human impact on biodiversity usually is measured by reduction in species abundance or richness. Just as important, but much more difficult to discern, is the anthropogenic elimination of ecological interactions. Here we report on the persistence of a long ecological interaction chain linking diverse food webs and habitats in the near-pristine portions of a remote Pacific atoll. Using biogeochemical assays, animal tracking, and field surveys we show that seabirds roosting on native trees fertilize soils, increasing coastal nutrients and the abundance of plankton, thus attracting manta rays to native forest coastlines. Partnered observations conducted in regions of this atoll where native trees have been replaced by human propagated palms reveal that this complex interaction chain linking trees to mantas readily breaks down. Taken together these findings provide a compelling example of how anthropogenic disturbance may be contributing to widespread reductions in ecological interaction chain length, thereby isolating and simplifying ecosystems.
authors.affiliation: Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA. mccauley@berkeley.edu
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: McCauley
authors.forename: Paul A
authors.initials: PA
authors.lastname: Desalles
authors.forename: Hillary S
authors.initials: HS
authors.lastname: Young
authors.forename: Robert B
authors.initials: RB
authors.lastname: Dunbar
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Dirzo
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Mills
authors.forename: Fiorenza
authors.initials: F
authors.lastname: Micheli
mesh_terms: D000818:Animals; D001717:Birds / Q000502:physiology*; D017753:Ecosystem; D020387:Food Chain; D005843:Geography; D006802:Human Activities; D006801:Humans; D008954:Models, Biological; D010140:Pacific Ocean; D010839:Phytoplankton / Q000254:growth & development; D054712:Salinity; D012987:Soil; D013696:Temperature; D014197:Trees / Q000254:growth & development; D014921:Wings, Animal / Q000502:physiology*; D015048:Zooplankton / Q000254:growth & development
chemical_list: D012987:Soil