title: Herbivory and Stoichiometric Feedbacks to Primary Production.
abstract: Established theory addresses the idea that herbivory can have positive feedbacks on nutrient flow to plants. Positive feedbacks likely emerge from a greater availability of organic carbon that primes the soil by supporting nutrient turnover through consumer and especially microbially-mediated metabolism in the detrital pool. We developed an entirely novel stoichiometric model that demonstrates the mechanism of a positive feedback. In particular, we show that sloppy or partial feeding by herbivores increases detrital carbon and nitrogen allowing for greater nitrogen mineralization and nutritive feedback to plants. The model consists of differential equations coupling flows among pools of: plants, herbivores, detrital carbon and nitrogen, and inorganic nitrogen. We test the effects of different levels of herbivore grazing completion and of the stoichiometric quality (carbon to nitrogen ratio, C:N) of the host plant. Our model analyses show that partial feeding and plant C:N interact because when herbivores are sloppy and plant biomass is diverted to the detrital pool, more mineral nitrogen is available to plants because of the stoichiometric difference between the organisms in the detrital pool and the herbivore. This model helps to identify how herbivory may feedback positively on primary production, and it mechanistically connects direct and indirect feedbacks from soil to plant production.
authors.affiliation: Department of Biology and Molecular Biology, Montclair State University, Montclair, New Jersey, United States of America; Department of Terrestrial Ecology, Netherlands Institute of Ecology, Wageningen, The Netherlands.
authors.forename: Jennifer Adams
authors.initials: JA
authors.lastname: Krumins
authors.affiliation: Department of Environmental Sciences, Rutgers University, New Brunswick, New Jersey, United States of America.
authors.forename: Valdis
authors.initials: V
authors.lastname: Krumins
authors.affiliation: Department of Mathematical Sciences, Montclair State University, Montclair, New Jersey, United States of America.
authors.forename: Eric
authors.initials: E
authors.lastname: Forgoston
authors.affiliation: Department of Mathematical Sciences, Montclair State University, Montclair, New Jersey, United States of America.
authors.forename: Lora
authors.initials: L
authors.lastname: Billings
authors.affiliation: Department of Terrestrial Ecology, Netherlands Institute of Ecology, Wageningen, The Netherlands; Laboratory of Nematology, Wageningen University, Wageningen, The Netherlands.
authors.forename: Wim H
authors.initials: WH
authors.lastname: van der Putten
mesh_terms: D000818:Animals; D018533:Biomass; D002244:Carbon / Q000032:analysis; D025461:Feedback, Physiological; D020387:Food Chain; D060434:Herbivory / Q000502:physiology*; D008954:Models, Biological; D009584:Nitrogen / Q000032:analysis; D018521:Plant Physiological Phenomena; D010944:Plants / Q000737:chemistry
chemical_list: D002244:Carbon; D009584:Nitrogen