title: Silicon-based plant defences, tooth wear and voles.
abstract: Plant-herbivore interactions are hypothesized to drive vole population cycles through the grazing-induced production of phytoliths in leaves. Phytoliths act as mechanical defences because they deter herbivory and lower growth rates in mammals. However, how phytoliths impair herbivore performance is still unknown. Here, we tested whether the amount of phytoliths changes tooth wear patterns. If confirmed, abrasion from phytoliths could play a role in population crashes. We applied dental microwear texture analysis (DMTA) to laboratory and wild voles. Lab voles were fed two pelleted diets with differing amounts of silicon, which produced similar dental textures. This was most probably due to the loss of food mechanical properties through pelletization and/or the small difference in silicon concentration between diets. Wild voles were trapped in Poland during spring and summer, and every year across a population cycle. In spring, voles feed on silica-rich monocotyledons, while in the summer they also include silica-depleted dicotyledons. This was reflected in the results; the amount of silica therefore leaves a traceable record in the dental microwear texture of voles. Furthermore, voles from different phases of population cycles have different microwear textures. We tentatively propose that these differences result from grazing-induced phytolith concentrations. We hypothesize that the high amount of phytoliths in response to intense grazing in peak years may result in malocclusion and other dental abnormalities, which would explain how these silicon-based plant defences help provoke population crashes. DMTA could then be used to reconstruct vole population dynamics using teeth from pellets or palaeontological material.
authors.affiliation: GEGENAA - EA 3795, Université de Reims Champagne-Ardenne, 51100 Reims, France calandra.ivan@gmail.com.
authors.forename: Ivan
authors.initials: I
authors.lastname: Calandra
authors.affiliation: Mammal Research Institute, Polish Academy of Sciences, 17-230 Białowiez˙a, Poland.
authors.forename: Karol
authors.initials: K
authors.lastname: Zub
authors.affiliation: Mammal Research Institute, Polish Academy of Sciences, 17-230 Białowiez˙a, Poland.
authors.forename: Paulina A
authors.initials: PA
authors.lastname: Szafrańska
authors.affiliation: Mammal Research Institute, Polish Academy of Sciences, 17-230 Białowiez˙a, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Zalewski
authors.affiliation: iPHEP UMR 7262, CNRS & Université de Poitiers, 86073 Poitiers, France.
authors.forename: Gildas
authors.initials: G
authors.lastname: Merceron
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000033:anatomy & histology / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D060434:Herbivory; D018515:Plant Leaves / Q000737:chemistry; D010944:Plants / Q000737:chemistry*; D011044:Poland; D012621:Seasons; D012822:Silicon Dioxide / Q000008:administration & dosage / Q000737:chemistry*; D057085:Tooth Wear
chemical_list: D012822:Silicon Dioxide
keywords: Arvicolinae; Dental microwear texture analysis; Feeding experiments; Phytoliths; Plant–herbivore interactions; Population cycles