title: When less is more: positive population-level effects of mortality.
abstract: Experimental and theoretical studies show that mortality imposed on a population can counter-intuitively increase the density of a specific life-history stage or total population density. Understanding positive population-level effects of mortality is advancing, illuminating implications for population, community, and applied ecology. Reconciling theory and data, we found that the mathematical models used to study mortality effects vary in the effects predicted and mechanisms proposed. Experiments predominantly demonstrate stage-specific density increases in response to mortality. We argue that the empirical evidence supports theory based on stage-structured population models but not on unstructured models. We conclude that stage-specific positive mortality effects are likely to be common in nature and that accounting for within-population individual variation is essential for developing ecological theory.
authors.affiliation: Department 4: Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587 Berlin, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Schröder
authors.affiliation: Department of Ecology and Evolutionary Biology, Princeton University, 106A Guyot Hall, Princeton, NJ 08544, USA. Electronic address: aleeuwen@princeton.edu.
authors.forename: Anieke
authors.initials: A
authors.lastname: van Leeuwen
authors.affiliation: School of Biological Sciences, University of Essex, Colchester, CO4 3SQ, UK.
authors.forename: Tom C
authors.initials: TC
authors.lastname: Cameron
mesh_terms: D000818:Animals; D018533:Biomass; D008018:Life Cycle Stages; D008962:Models, Theoretical; D009026:Mortality; D011156:Population Density; D011157:Population Dynamics
keywords: biomass overcompensation; consumer-resource model; density dependence; fisheries; hydra effect; mortality; numerical response; pest control; population dynamics; population management; predation; size-structure; stage-structure