Food-web models predict species abundances in response to habitat change.
Plant and animal population sizes inevitably change following habitat loss, but the mechanisms underlying these changes are poorly understood. We experimentally altered habitat volume and eliminated top trophic levels of the food web of invertebrates that inhabit rain-filled leaves of the carnivorous pitcher plant Sarracenia purpurea. Path models that incorporated food-web structure better predicted population sizes of food-web constituents than did simple keystone species models, models that included only autecological responses to habitat volume, or models including both food-web structure and habitat volume. These results provide the first experimental confirmation that trophic structure can determine species abundances in the face of habitat loss.
Gotelli
Nicholas J
NJ
Department of Biology, University of Vermont Burlington, Burlington, Vermont, USA. ngotelli@uvm.edu
Ellison
Aaron M
AM
D000818:Animals; D044822:Biodiversity; D004463:Ecology; D017753:Ecosystem; D004777:Environment; D005069:Evaluation Studies as Topic; D020387:Food Chain; D007448:Invertebrates / Q000502:physiology; D008954:Models, Biological; D018521:Plant Physiological Phenomena; D011157:Population Dynamics; D011235:Predatory Behavior; D052583:Sarraceniaceae / Q000502:physiology*