title: Mechanical vulnerability explains size-dependent mortality of reef corals.
abstract: Understanding life history and demographic variation among species within communities is a central ecological goal. Mortality schedules are especially important in ecosystems where disturbance plays a major role in structuring communities, such as coral reefs. Here, we test whether a trait-based, mechanistic model of mechanical vulnerability in corals can explain mortality schedules. Specifically, we ask whether species that become increasingly vulnerable to hydrodynamic dislodgment as they grow have bathtub-shaped mortality curves, whereas species that remain mechanically stable have decreasing mortality rates with size, as predicted by classical life history theory for reef corals. We find that size-dependent mortality is highly consistent between species with the same growth form and that the shape of size-dependent mortality for each growth form can be explained by mechanical vulnerability. Our findings highlight the feasibility of predicting assemblage-scale mortality patterns on coral reefs with trait-based approaches.
authors.affiliation: Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia.
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Madin
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Baird
authors.forename: Maria
authors.initials: M
authors.lastname: Dornelas
authors.forename: Sean R
authors.initials: SR
authors.lastname: Connolly
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000502:physiology*; D016015:Logistic Models; D008954:Models, Biological; D009026:Mortality; D011156:Population Density; D013314:Stress, Mechanical
keywords: Biomechanics; colonial; demography; disturbance; life history; mortality; reef coral