Mechanical vulnerability explains size‐dependent mortality of reef corals

• Published in: Ecology letters Vol. 17; no. 8; pp. 1008 - 1015
• Main Authors: Madin, Joshua S, Baird, Andrew H, Dornelas, Maria, Connolly, Sean R, Cornell, Howard
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Science 01.08.2014; Blackwell Publishing Ltd; Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Anthozoa - physiology; Biological and medical sciences; Biomechanics; Cnidaria. Ctenaria; colonial; Coral reefs; corals; Demecology; demography; disturbance; ecosystems; Fundamental and applied biological sciences. Psychology; General aspects; hydrodynamics; Invertebrates; Letters; life history; Logistic Models; Marine biology; Models, Biological; Mortality; Population Density; prediction; reef coral; Stress, Mechanical; disturbance; Life history; Demography; Mortality; Coral reef; Vulnerability; Perturbation; reef coral; Biomechanics; Coelenterata; colonial; Cnidaria; Population dynamics; Invertebrata; demography; life history; mortality
• ISSN: 1461-023X; 1461-0248
• DOI: 10.1111/ele.12306

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.